INFORMATION
STORAGE AND
MANAGEMENT (ISM) V4
Revision [1.0]
PARTICIPANT GUIDE
PARTICIPANT GUIDE
Dell Confidential and Proprietary
Copyright © 2019 Dell Inc. or its subsidiaries. All Rights Reserved. Dell Technologies,
Dell, EMC, Dell EMC and other trademarks are trademarks of Dell Inc. or its
subsidiaries. Other trademarks may be trademarks of their respective owners.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page i
Table of Contents
Course Introduction.................................................................................. 1
Information Storage and Management (ISM) v4 ...................................................... 2
Prerequisite Skills ................................................................................................................ 3
Course Agenda .................................................................................................................... 4
Introduction to Information Storage ........................................................ 5
Introduction to Information Storage ......................................................................... 6
Introduction to Information Storage ...................................................................................... 7
Assessment ....................................................................................................................... 24
Summary................................................................................................................... 25
Modern Technologies Driving Digital Transformation ......................... 26
Cloud Computing Lesson ....................................................................................... 27
Cloud Computing ............................................................................................................... 28
Big Data Analytics Lesson ...................................................................................... 51
Big Data Analytics .............................................................................................................. 52
Internet of Things Lesson ....................................................................................... 68
Internet of Things ............................................................................................................... 69
Machine Learning Lesson ....................................................................................... 75
Machine Learning .............................................................................................................. 76
Concepts in Practice Lesson .................................................................................. 82
Concepts in Practice .......................................................................................................... 83
Assessment ....................................................................................................................... 85
Summary................................................................................................................... 86
Information Storage and Management (ISM) v4
Page ii
© Copyright 2019 Dell Inc.
Modern Data Center Environment ......................................................... 87
Compute System Lesson ........................................................................................ 88
Compute System ............................................................................................................... 89
Compute and Desktop Virtualization Lesson ...................................................... 105
Compute and Desktop Virtualization ................................................................................ 106
Storage and Network Lesson ................................................................................ 122
Storage and Network ....................................................................................................... 123
Applications Lesson .............................................................................................. 135
Applications ..................................................................................................................... 136
Software-Defined Data Center (SDDC) Lesson ................................................... 146
Software-Defined Data Center (SDDC) ............................................................................ 147
Modern Data Center Infrastructure Lesson ......................................................... 152
Modern Data Center Infrastructure ................................................................................... 153
Concepts in Practice Lesson ................................................................................ 170
Concepts in Practice ........................................................................................................ 171
Assessment ..................................................................................................................... 177
Summary................................................................................................................. 178
Intelligent Storage Systems ................................................................. 179
Components of Intelligent Storage Systems Lesson ......................................... 180
ISMv4 Source - Intelligent Storage Systems - Components ............................................. 181
RAID Techniques Lesson ...................................................................................... 211
RAID Techniques ............................................................................................................. 212
Types of Intelligent Storage Systems Lesson ..................................................... 233
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page iii
Types of Intelligent Storage Systems ............................................................................... 234
Assessment ..................................................................................................................... 238
Summary................................................................................................................. 239
Block-Based Storage System .............................................................. 240
Components of a Block-Based Storage System Lesson.................................... 241
Components of a Block-Based Storage System ............................................................... 242
Storage Provisioning Lesson ............................................................................... 256
Storage Provisioning ........................................................................................................ 257
Storage Tiering Lesson ......................................................................................... 269
Storage Tiering ................................................................................................................ 270
Concepts in Practice Lesson ................................................................................ 278
Concepts in Practice ........................................................................................................ 279
Assessment ..................................................................................................................... 282
Summary................................................................................................................. 283
Fibre Channel SAN ............................................................................... 284
Introduction to SAN Lesson .................................................................................. 285
Introduction to SAN .......................................................................................................... 286
FC SAN Overview Lesson ..................................................................................... 289
FC SAN Overview ............................................................................................................ 290
FC Architecture Lesson......................................................................................... 302
FC SAN Architecture........................................................................................................ 303
Topologies, Link Aggregation and Zoning Lesson ............................................. 314
Topologies, Link Aggregation and Zoning ........................................................................ 315
SAN Virtualization Lesson .................................................................................... 328
Information Storage and Management (ISM) v4
Page iv
© Copyright 2019 Dell Inc.
SAN Virtualization ............................................................................................................ 329
Concepts in Practice Lesson ................................................................................ 339
Concepts In Practice ........................................................................................................ 340
Assessment ..................................................................................................................... 343
Summary................................................................................................................. 344
IP and FCoE SAN .................................................................................. 345
Overview of TCP/IP Lesson................................................................................... 346
Overview of TCP/IP ......................................................................................................... 347
Overview of IP SAN Lesson .................................................................................. 356
Overview of IP SAN ......................................................................................................... 357
iSCSI Lesson .......................................................................................................... 363
iSCSI ............................................................................................................................... 364
FCIP Lesson ........................................................................................................... 386
FCIP ................................................................................................................................ 387
FCoE Lesson .......................................................................................................... 395
FCoE ............................................................................................................................... 396
Concepts in Practice Lesson ................................................................................ 404
Concepts In Practice ........................................................................................................ 405
Assessment ..................................................................................................................... 408
Summary................................................................................................................. 409
File-Based and Object-Based Storage System ................................... 410
NAS Components and Architecture Lesson ........................................................ 411
NAS Components and Architecture ................................................................................. 412
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page v
File-Level Virtualization and Tiering Lesson ....................................................... 432
File-Level Virtualization and Tiering ................................................................................. 433
Object-Based and Unified Storage Lesson .......................................................... 440
Object-Based and Unified Storage Overview ................................................................... 441
Concepts in Practice Lesson ................................................................................ 462
Concepts in Practice ........................................................................................................ 463
Assessment ..................................................................................................................... 465
Summary................................................................................................................. 466
Software-Defined Storage and Networking ......................................... 467
Software-Defined Storage (SDS) Lesson ............................................................. 468
Software-Defined Storage (SDS) ..................................................................................... 469
Software-Defined Networking (SDN) Lesson ....................................................... 493
Software-Defined Networking (SDN) ................................................................................ 494
Concepts in Practice Lesson ................................................................................ 502
Concepts in Practice ........................................................................................................ 503
Assessment ..................................................................................................................... 505
Summary................................................................................................................. 506
Introduction to Business Continuity ................................................... 507
Business Continuity Overview Lesson ................................................................ 508
Business Continuity Overview .......................................................................................... 509
Business Continuity Fault Tolerance Lesson ..................................................... 529
Fault Tolerance IT Infrastructure ...................................................................................... 530
Concepts in Practice Lesson ................................................................................ 556
Concepts In Practice ........................................................................................................ 557
Information Storage and Management (ISM) v4
Page vi
© Copyright 2019 Dell Inc.
Assessment ..................................................................................................................... 560
Summary................................................................................................................. 561
Data Protection Solutions .................................................................... 562
Replication Lesson ................................................................................................ 563
Replication ....................................................................................................................... 564
Backup and Recovery Lesson .............................................................................. 594
Backup and Recovery Overview ...................................................................................... 595
Data Deduplication Lesson ................................................................................... 622
Data Deduplication........................................................................................................... 623
Data Archiving Lesson .......................................................................................... 634
ISMv4 Source - Data Protection Solutions - Data Archiving ............................................. 635
Migration Lesson ................................................................................................... 647
Migration .......................................................................................................................... 648
Concepts in Practice Lesson ................................................................................ 660
Concepts In Practice ........................................................................................................ 661
Assessment ..................................................................................................................... 672
Summary................................................................................................................. 674
Storage Infrastructure Security ........................................................... 675
Introduction to Information Security Lesson ...................................................... 676
Introduction to Information Security .................................................................................. 677
Storage Security Domains and Threats Lesson .................................................. 691
Storage Security Domains and Threats............................................................................ 692
Security Controls Lesson...................................................................................... 703
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page vii
Security Controls.............................................................................................................. 704
Concepts in Practice Lesson ................................................................................ 730
Concepts in Practice ........................................................................................................ 731
Assessment ..................................................................................................................... 735
Summary................................................................................................................. 736
Storage Infrastructure Management.................................................... 737
Introduction to Storage Infrastructure Management Lesson ............................. 738
Introduction to Storage Infrastructure Management ......................................................... 739
Operations Management ....................................................................................... 751
Operations Management.................................................................................................. 752
Concepts in Practice Lesson ................................................................................ 790
Concepts In Practice ........................................................................................................ 791
Assessment ..................................................................................................................... 793
Summary................................................................................................................. 794
Course Conclusion ............................................................................... 795
Information Storage and Management (ISM) v4 .................................................. 796
Summary ......................................................................................................................... 797
Information Storage and Management (ISM) v4
Page viii
© Copyright 2019 Dell Inc.
Course Introduction
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 1
Information Storage and Management (ISM) v4
Information Storage and Management (ISM) v4
Introduction
Information Storage and Management (ISM) is a unique course that provides a
comprehensive understanding of the various storage infrastructure components in
a modern data center environment. Participants will learn the architectures,
features, and benefits of intelligent storage systems including block-based, filebased, object-based, and unified storage; software-defined storage; storage
networking technologies such as FC SAN, IP SAN, and FCoE SAN; business
continuity solutions such as backup and replication; the highly-critical area of
information security; and storage infrastructure management. This course takes an
open-approach to describe all the concepts and technologies, which are further
illustrated and reinforced with Dell products and based on real world use cases.
This course aligns to the Associate level proven professional certification which
serves as a baseline for a number of additional product specializations.
Information Storage and Management (ISM) v4
Page 2
© Copyright 2019 Dell Inc.
Information Storage and Management (ISM) v4
Prerequisite Skills
The following skills are prerequisites:

To understand the content and successfully complete this course, a participant
must have a basic understanding of computer architecture, operating systems,
networking, and databases

Participants with experience in specific segments of storage infrastructure
would also be able to assimilate the course material
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 3
Information Storage and Management (ISM) v4
Course Agenda
Introductions
Information Storage and Management (ISM) v4
Page 4
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Introduction
This module presents digital data, types of digital data, and information. This
module also focuses on data center characteristics and technologies driving digital
transformation.
Upon completing this module, you will be able to:
 Describe digital data, types of digital data, and information
 Describe data center and its key characteristics
 Describe the technologies driving digital transformation
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 5
Introduction to Information Storage
Introduction to Information Storage
Information Storage and Management (ISM) v4
Page 6
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Introduction to Information Storage
Growth of the Digital Universe

Digital universe is created and defined by
software
 Digital data is continuously generated,
collected, stored, and analyzed through
software

IDC report predicts worldwide data creation will
grow to an enormous 163 (ZB) by 2025

Technologies driving digital transformation add to data growth
Notes
We live in a digital universe – software creates and defines a world. A massive
amount of digital data is continuously generated, collected, stored, and analyzed
through software in the digital universe. IDC report predicts worldwide data creation
will grow to an enormous 163 zettabytes (ZB) by 2025.
The data in the digital universe comes from diverse sources, including both
individuals and organizations. Individuals constantly generate and consume
information through numerous activities, such as web searches, emails, uploading
and downloading content and sharing media files. In organizations, the volume and
importance of information for business operations continue to grow at astounding
rates. Technologies driving digital transformation including Internet of Things (IoT)
have significantly contributed to the growth of the digital universe.
In the past, individuals created most of the data in the world. Now IDC predicts
organizations will create 60 percent of world’s data through applications relying on
machine learning, automation, machine-to-machine technologies, and embedded
devices.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 7
Introduction to Information Storage
Why Information Storage and Management

Organizations are dependent on continuous and reliable access to information

Organizations seek to store, protect, process, manage, and use information

Organizations are increasingly implementing intelligent storage solutions:
 To efficiently store and manage information
 To gain competitive advantage
 To derive new business opportunities
Notes
Organizations have become increasingly
information-dependent in the 21st century, and
information must be available whenever and
wherever it is required. It is critical for users and applications to have continuous,
fast, reliable, and secure access to information for business operations to run as
required. Some examples of such organizations and processes include banking
and financial institutions, online retailers, airline reservations, social networks, stock
trading, scientific research, and healthcare.
Data is the lifeblood of a rapidly growing digital existence, opening up new
opportunities for businesses and gain a competitive edge. For example, an online
retailer may need to identify the preferred product types and brands of customers
by analyzing their search, browsing, and purchase patterns. This information helps
the retailer to maintain a sufficient inventory of popular products, and also advertise
relevant products to the existing and potential customers. It is essential for
organizations to store, protect, process, and manage information in an efficient and
cost-effective manner. Legal, regulatory, and contractual obligations regarding the
availability, retention, and protection of data further add to the challenges of storing
and managing information.
To meet all these requirements and more, organizations are increasingly
undertaking digital transformation initiatives to implement intelligent storage
solutions. These solutions enable efficient and optimized storage and management
of information. They also enable extraction of value from information to derive new
Information Storage and Management (ISM) v4
Page 8
© Copyright 2019 Dell Inc.
Introduction to Information Storage
business opportunities, gain a competitive advantage, and create sources of
revenue.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 9
Introduction to Information Storage
Digital Data
Definition: Digital Data
A collection of facts that is transmitted and stored in electronic form,
and processed through software.
Video
Laptop
Text
Photos
Desktop
Internal or External Storage
Digital Data
Tablet and Mobile
Notes
A generic definition of data is that it is a collection of facts, typically collected for
analysis or reference. Data can exist in various forms such as facts stored in a
person's mind, photographs and drawings, a bank ledger, and tabled results of a
scientific survey. Digital data is a collection of facts that is transmitted and stored in
electronic form, and processed through software. Devices such as desktops,
laptops, tablets, mobile phones, and electronic sensors generate digital data.
Digital data is stored as strings of binary values on a storage medium. This storage
medium is either internal or external to the devices generating or accessing the
data. The storage devices may be of different types, such as magnetic, optical, or
SSD. Examples of digital data are electronic documents, text files, emails, ebooks,
digital images, digital audio, and digital video.
Information Storage and Management (ISM) v4
Page 10
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Types of Digital Data
Unstructured
Quasi-Structured
Semi-Structured
Structured

Unstructured data has no inherent structure and is usually stored as different
types of files
 Text documents, PDFs, images, and videos

Quasi-structured data consists of textual data with erratic formats that can be
formatted with effort and software tools
 Clickstream data

Semi-structured data consists of textual data files with an apparent pattern,
enabling analysis
 Spreadsheets and XML files

Structured data has a defined data model, format, structure
 Database
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 11
Introduction to Information Storage
Notes
Based on how it is stored and managed, digital data can be broadly categorized
into structured, semi-structured, quasi-structured, and unstructured.

Structured data is organized in fixed fields within a record or file. To structure
the data, you require a data model. A data model specifies the format for
organizing data, and also specifies how different data elements are related to
each other. For example, in a relational database, data is organized in rows and
columns within named tables.

Semi-structured data does not have a formal data model but has an apparent,
self-describing pattern and structure that enable its analysis. Examples of semistructured data include spreadsheets that have a row and column structure, and
XML files that are defined by an XML schema.

Quasi-structured data consists of textual data with erratic data formats, and
can be formatted with effort, software tools, and time. An example of quasistructured data is a “clickstream” that includes data about which webpages a
user visited and in what order – which is the result of the successive mouse
clicks the user made. A clickstream shows when a user entered a website, the
pages viewed, the time that is spent on each page, and when the user exited.

Unstructured data does not have a data model and is not organized in any
particular format. Some examples of unstructured data include text documents,
PDF files, emails, presentations, images, and videos.
The majority, which is more than 90 percent of the data that is generated in the
digital universe today is non-structured data (semi-, quasi-, and unstructured).
Although the illustration shows four different and separate types of data, in reality a
mixture of these data is typically generated.
Information Storage and Management (ISM) v4
Page 12
© Copyright 2019 Dell Inc.
Introduction to Information Storage
What is Information?
Definition: Information
Processed data that is presented in a specific content to enable useful
interpretation and decision-making.

Example: Annual sales data processed into a sales report
 Enables calculation of the average sales for a product and the comparison
of actual sales to projected sales

Emerging architectures and technologies enable extracting information from
non-structured data
Notes
The terms “data” and “information” are closely related and you can use these two
terms interchangeably. However, it is important to understand the difference
between the two. Data, by itself, is simply a collection of facts that requires
processing for it to be useful. For example, annual sales figures of an organization
is data. When data is processed and in a specific context, it can be interpreted in a
useful manner. This processed and organized data is called information.
For example, when you process the annual sales data into a sales report, it
provides useful information, such as the average sales for a product (indicating
product demand and popularity), and a comparison of the actual sales to the
projected sales.
Information thus creates knowledge and enables decision-making. Processing and
analyzing data is vital to any organization. It enables organizations to derive value
from data, and create intelligence to enable decision-making and organizational
effectiveness. It is easier to process structured data due to its organized form. On
the other hand, processing non-structured data and extracting information from it
using traditional applications is difficult, time-consuming, and requires considerable
resources. Emerging architectures, technologies, and techniques enable storing,
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 13
Introduction to Information Storage
managing, analyzing, and deriving value from unstructured data coming from
numerous sources.
Information Storage and Management (ISM) v4
Page 14
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Information Storage

Information is stored on storage devices on non-volatile media
 Magnetic storage devices: Hard disk drive and magnetic tape drive
 Optical storage devices: Blu-ray, DVD, and CD
 Flash-based storage devices: Solid-state drive (SSD), memory card, and
USB thumb drive

Storage devices are assembled within a storage system or “array”
 Provides high capacity, scalability, performance, reliability, and security

Storage systems along with other IT infrastructure are housed in a data center
Notes
In a computing environment, storage devices (or storage) are devices consisting of
nonvolatile recording media on which digital data or information can be persistently
stored. Storage may be internal or external to a compute system. Based on the
nature of the storage media used, storage devices are classified as: magnetic
storage devices, optical storage devices, or flash-based storage devices.
Storage is a core component in an organization’s IT infrastructure. Various factors
such as the media, architecture, capacity, addressing, reliability, and performance
influence the choice and use of storage devices in an enterprise environment. For
example, disk drives and SSDs are used for storing business-critical information
that needs to be continuously accessible to applications. Magnetic tapes and
optical storage are typically used for backing up and archiving data.
In enterprise environments, information is typically stored on storage
systems/storage arrays. A storage system is a hardware component that contains a
group of homogeneous/heterogeneous storage devices that are assembled within
a cabinet. These enterprise-class storage systems are designed for high capacity,
scalability, performance, reliability, and security to meet business requirements.
The compute systems that run business applications are provided storage capacity
from storage systems. Storage systems are covered in Module, ‘Intelligent Storage
Systems (ISS)’. Organizations typically house their IT infrastructure, including
compute systems, storage systems, and network equipment within a data center.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 15
Introduction to Information Storage
Information Storage and Management (ISM) v4
Page 16
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Data Center

A data center typically comprises:
 Facility: The building and floor space where
the data center is constructed
 IT equipment: Compute system, storage, and
connectivity elements
 Support infrastructure: Power supply, fire
detection, HVAC, and security systems

Organizations are moving towards modern data
center to overcome the business and IT
challenges
 Helps them to be successful in their digital
transformation journey
Notes
A data center is a dedicated facility where an organization houses, operates, and
maintains its IT infrastructure along with other supporting infrastructures. It
centralizes an organization’s IT equipment and data-processing operations. A data
center may be constructed in-house and located in an organization’s own facility.
The data center may also be outsourced, with equipment being at a third-party site.
A data center typically consists of the following:

Facility: It is the building and floor space where organizations construct the data
center. It typically has a raised floor with ducts underneath holding power and
network cables.

IT equipment: It includes components such as compute systems, storage, and
connectivity elements along with cabinets for housing the IT equipment.

Support infrastructure: It includes power supply, fire, heating, ventilation, and air
conditioning (HVAC) systems. It also includes security systems such as
biometrics, badge readers, and video surveillance systems.
Digital transformation is disrupting every industry, and with the evolution of modern
technologies, organizations are facing too many business challenges.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 17
Introduction to Information Storage
Organizations must operate in real time, develop smarter products, and deliver a
great user experience. They must be agile, operate efficiently, and make decisions
quickly to be successful. However, these disruptive technologies along with agile
methodologies are less resilient on traditional IT infrastructure and services.
Organization’s IT department also faces several challenges in supporting business
challenges. So, organizations are moving towards modern data center to overcome
the business challenges and be successful in their digital transformation journey.
Information Storage and Management (ISM) v4
Page 18
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Key Characteristics of a Data Center
Data centers are designed and built to fulfill the key characteristics as shown in the
figure. Although the characteristics are applicable to almost all data center
components, the details here primarily focus on storage systems.
Availability
Data Integrity
Security
Manageability
Performance
Capacity
Scalability
Notes
Data center characteristics are:

Availability: Availability of information as and when required should be
ensured. Unavailability of information can severely affect business operations,
lead to substantial financial losses, and damage the reputation of an
organization.

Security: Policies and procedures should be established, and control measures
should be implemented to prevent unauthorized access to and alteration of
information.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 19
Introduction to Information Storage

Capacity: Data center operations require adequate resources to efficiently store
and process large and increasing amounts of data. When capacity requirements
increase, additional capacity should be provided either without interrupting the
availability or with minimal disruption. Capacity may be managed by adding new
resources or by reallocating existing resources.

Scalability: Organizations may need to deploy additional resources such as
compute systems, new applications, and databases to meet the growing
requirements. Data center resources should scale to meet the changing
requirements, without interrupting business operations.

Performance: Data center components should provide optimal performance
based on the required service levels.

Data integrity: Data integrity refers to mechanisms, such as error correction
codes or parity bits, which ensure that data is stored and retrieved exactly as it
was received.

Manageability: A data center should provide easy, flexible, and integrated
management of all its components. Efficient manageability can be achieved
through automation for reducing manual intervention in common, repeatable
tasks.
Information Storage and Management (ISM) v4
Page 20
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Digital Transformation
Digital transformation puts technology at the heart of an organization’s products,
services, and operations.
Notes
Digital transformation is imperative for all businesses. Businesses of all shapes and
sizes are changing to a more digital mindset. This digital mindset is being driven by
the need to innovate more quickly. Digital transformation puts technology at the
heart of an organization’s products, services, and operations.
In general terms, digital transformation is defined as the integration of digital
technology into all areas of a business. This results in fundamental changes to how
businesses operate and how they deliver value to customers, improve efficiency,
reduce business risks, and uncover new opportunities.
With people, customers, businesses, and things communicating, transacting, and
negotiating with each other, a new world comes into being. It is the world of the
digital business that uses data as a way to create value. According to Gartner, by
2020, more than seven billion people and businesses, and at least 30 billion
devices, will be connected to the Internet. Organizations need to accelerate their
digital transformation journeys to avoid being left behind in an increasingly digital
world.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 21
Introduction to Information Storage
Information Storage and Management (ISM) v4
Page 22
© Copyright 2019 Dell Inc.
Introduction to Information Storage
Key Technologies Driving Digital Transformation
In this digital world, organizations need to develop new applications using agile
processes and new tools to assure rapid time-to-market. Simultaneously, the
organizations still expect IT to operate and manage the traditional applications
which provide much revenue.
To survive, the organization has to transform and adopt modern technologies to
support the digital transformation. Some of the key technologies that drive digital
transformation are listed in the figure.
Cloud
Big Data Analytics
Internet of Things
Machine Learning
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 23
Introduction to Information Storage
Assessment
1. Which data asset is an example of unstructured data?
A. XML data file
B. News article text
C. Database tableTBF
D. Webserver log
2. Why are businesses undergoing the digital transformation?
A. To innovate more quickly
B. To avoid security risks
C. To avoid compliance penalty
D. To eliminate management costs
Information Storage and Management (ISM) v4
Page 24
© Copyright 2019 Dell Inc.
Summary
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 25
Modern Technologies Driving Digital Transformation
Introduction
This module presents an overview on the modern technologies that are driving
digital transformation in today’s world. The modern technologies covered in this
lesson include cloud computing, big data analytics, Internet of Things (IoT), and
machine learning.
Upon completing this module, you will be able to:




Describe cloud computing
Describe Big Data analytics
Describe Internet of Things
Describe machine learning
Information Storage and Management (ISM) v4
Page 26
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Cloud Computing Lesson
Introduction
This lesson presents an overview of cloud computing along with its essential
characteristics, various cloud deployment and service models, and uses cases.
This lesson covers the following topics:

Cloud computing and its essential characteristics

Cloud service models

Cloud deployment models

Use cases of cloud computing
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 27
Cloud Computing Lesson
Cloud Computing
Cloud Computing: An Overview
Definition: Cloud Computing
A model for enabling convenient, on-demand network access to a
shared pool of configurable computing resources (for example,
networks, servers, storage, applications, and services) that can be
rapidly provisioned and released with minimal management effort or
service provider interaction.
Source: The National Institute of Standards and Technology (NIST)—
a part of the U.S. Department of Commerce—in its Special
Publication 800-145
Cloud Infrastructure
Desktop
VM
VM
APP
APP
OS
OS
Applications
Hypervisor
LAN/WAN
Laptop
Compute
Network
Storage
Applications
Platform Software
Tablet and
Mobile
Information Storage and Management (ISM) v4
Page 28
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Notes
The term “cloud” originates from the cloud-like bubble that is commonly used in
technical architecture diagrams to represent a system. This system may be the
Internet, a network, or a compute cluster. In cloud computing, a cloud is a collection
of IT resources, including hardware and software resources. You can deploy these
resources either in a single data center, or across multiple geographically
dispersed data centers that are connected over a network.
A cloud service provider is responsible for building, operating, and managing cloud
infrastructure. The cloud computing model enables consumers to hire IT resources
as a service from a provider. A cloud service is a combination of hardware and
software resources that are offered for consumption by a provider. The cloud
infrastructure contains IT resource pools, from which you can provision resources
to consumers as services over a network, such as the Internet or an intranet.
Resources are returned to the pool when the consumer releases them.
Example: The cloud model is similar to utility services such as electricity, water,
and telephone. When consumers use these utilities, they are typically unaware of
how the utilities are generated or distributed. The consumers periodically pay for
the utilities based on usage. Similarly, in cloud computing, the cloud is an
abstraction of an IT infrastructure. Consumers hire IT resources as services from
the cloud without the risks and costs that are associated with owning the resources.
Cloud services are accessed from different types of client devices over wired and
wireless network connections. Consumers pay only for the services that they use,
either based on a subscription or based on resource consumption.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 29
Cloud Computing Lesson
Essential Cloud Characteristics
In SP 800-145, NIST specifies that a cloud infrastructure should have the five
essential characteristics.
Measured Service
Resource Pooling
Cloud Characteristics
Rapid Elasticity
On-demand Selfservice
Broad Network
Access
Notes
The five characteristics are:

Measured Service: “Cloud systems automatically control and optimize
resource use by leveraging a metering capability at some level of abstraction
appropriate to the type of service (for example, storage, processing, bandwidth,
and active user accounts). Resource usage can be monitored, controlled, and
reported, providing transparency for both the provider and consumer of the
utilized service.” – NIST

Resource Pooling: “The provider’s computing resources are pooled to serve
multiple consumers using a multitenant model, with different physical and virtual
resources that are dynamically assigned and reassigned according to consumer
demand. There is a sense of location independence in that the customer
generally has no control or knowledge over the exact location of the provided
Information Storage and Management (ISM) v4
Page 30
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
resources but may be able to specify location at a higher level of abstraction (for
example, country, state, or datacenter). Examples of resources include storage,
processing, memory, and network bandwidth.” – NIST

Rapid Elasticity: “Capabilities can be rapidly and elastically provisioned, in
some cases automatically, to scale rapidly outward and inward commensurate
with demand. To the consumer, the capabilities available for provisioning often
appear to be unlimited and can be appropriated in any quantity at any time.” –
NIST

On-demand Self-service: “A consumer can unilaterally provision computing
capabilities, such as server time or networked storage, as needed automatically
without requiring human interaction with each service provider.” – NIST

Broad Network Access: “Capabilities are available over the network and
accessed through standard mechanisms that promote use by heterogeneous
thin or thick client platforms (for example, mobile phones, tablets, laptops, and
workstations).” – NIST
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 31
Cloud Computing Lesson
Cloud Service Models
Infrastructure as a Service
Cloud Service Models
Platform as a Service
Software as a Service

A cloud service model specifies the services and the capabilities that are
provided to consumers

In SP 800-145, NIST classifies cloud service offerings into the three primary
models:
 Infrastructure as a Service (IaaS)
 Platform as a Service (PaaS)
 Software as a Service (SaaS)
Notes
Cloud administrators or architects assess and identify potential cloud service
offerings. The assessment includes evaluating what services to create and
upgrade, and the necessary feature set for each service. It also includes the
service level objectives (SLOs) of each service aligning to consumer needs and
market conditions. SLOs are specific measurable characteristics such as
availability, throughput, frequency, and response time. They provide a
measurement of performance of the service provider. SLOs are key elements of a
Information Storage and Management (ISM) v4
Page 32
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
service level agreement (SLA). SLA is a legal document that describes items such
as what service level will be provided, how it will be supported, service location,
and the responsibilities of the consumer and the provider.
Many alternate cloud service models based on IaaS, PaaS, and SaaS are defined
in various publications and by different industry groups. These service models are
specific to the cloud services and capabilities that are provided. Examples of such
service models include Network as a Service (NaaS), Database as a Service
(DBaaS), Big Data as a Service (BDaaS), Security as a Service (SECaaS), and
Disaster Recovery as a Service (DRaaS). However, these models eventually
belong to one of the three primary cloud service models.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 33
Cloud Computing Lesson
Infrastructure as a Service (IaaS)
Definition: Infrastructure as a Service
“The capability provided to the consumer is to provision processing,
storage, networks, and other fundamental computing resources where
the consumer is able to deploy and run arbitrary software, which can
include operating systems and applications. The consumer does not
manage or control the underlying cloud infrastructure but has control
over operating systems, storage, and deployed applications; and
possibly limited control of select networking components (for example,
host firewalls).” – NIST

IaaS pricing may be subscription-based or based on resource usage
 Provider pools the underlying IT resources and multiple consumers share
these resources through a multitenant model

Organizations can even implement IaaS internally, where internal IT manages
the resources and services
Examples:
Application
Database
- Amazon EC2, S3
Consumer's Resources
Programming Framework
- Virtustream
Operating System
- Google Compute Engine
Cloud Infrastructure
Compute
Provider's Resources
Storage
Network
Information Storage and Management (ISM) v4
Page 34
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 35
Cloud Computing Lesson
Platform as a Service (PaaS)
Definition: Platform as a Service

In the PaaS model, a cloud service includes compute, storage, and network
resources along with platform software

Platform software includes software such as:
 Operating system, database, programming frameworks, middleware
 Tools to develop, test, deploy, and manage applications

Most PaaS offerings support multiple operating systems and programming
frameworks for application development and deployment

Typically you can calculate PaaS usage fees based on the following factors:
 Number of consumers
 Types of consumers (developer, tester, and so on)
 The time for which the platform is in use
 The compute, storage, or network resources that the platform consumes
Information Storage and Management (ISM) v4
Page 36
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Consumer's Resources
Application
Database
Programming Framework
Operating System
Cloud
Infrastructure
Provider's Resources
Compute
Storage
Network
Examples:
- Pivotal Cloud Foundry
- Google App Engine
- AWS Elastic Beanstalk
- Microsoft Azure
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 37
Cloud Computing Lesson
Software as a Service (SaaS)
Definition: Software as a Service
“The capability provided to the consumer is to use the provider’s
applications running on a cloud infrastructure. The applications are
accessible from various client devices through either a thin client
interface, such as a web browser (for example, web-based email), or
a program interface. The consumer does not manage or control the
underlying cloud infrastructure including network, servers, operating
systems, storage, or even individual application capabilities, except
limited user-specific application configuration settings.” – NIST

In the SaaS model, a provider offers a cloud-hosted application to multiple
consumers as a service
 The consumers do not own or manage any aspect of the cloud infrastructure

Some SaaS applications may require installing a client interface locally on an
end-point device

Examples of applications that are delivered through SaaS:
 Customer Relationship Management (CRM)
 Enterprise Resource Planning (ERP)
 Email and Office Suites
Information Storage and Management (ISM) v4
Page 38
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Application
Database
Programming Framework
Provider's Resources
Operating System
Cloud Infrastructure
Compute
Storage
Network
Examples:
- Salesforce
- Google Apps
- Microsoft Office 365
- Oracle
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 39
Cloud Computing Lesson
Cloud Deployment Models

A cloud deployment model provides a basis for how cloud infrastructure is built,
managed, and accessed

In SP 800 to 145, NIST specifies the four primary cloud deployment models
listed in the figure

Each cloud deployment model may be used for any of the cloud service models:
IaaS, PaaS, and SaaS

The different deployment models present several tradeoffs in terms of control,
scale, cost, and availability of resources
Public Cloud
Private Cloud
Cloud Deployment Models
Hybrid Cloud
Community Cloud
Information Storage and Management (ISM) v4
Page 40
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Public Cloud
Definition: Public Cloud
“The cloud infrastructure is provisioned for open use by the general
public. It may be owned, managed, and operated by a business,
academic, or government organization, or some combination of them.
It exists on the premises of the cloud provider.” – NIST

Public cloud services may be free, subscription-based, or provided on a payper-use model
 A public cloud provides the benefits of low upfront expenditure on IT
resources and enormous scalability

Some concerns for the consumers include:
 Network availability
 Risks associated with multitenancy
 Visibility
 Control over the cloud resources and data
 Restrictive default service levels.
Enterprise Q
Enterprise P
Resources of
Cloud Provider
VM
VM
Individual R
Hypervisor
Applications
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 41
Cloud Computing Lesson
Information Storage and Management (ISM) v4
Page 42
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Private Cloud
Definition: Private Cloud
“The cloud infrastructure is provisioned for exclusive use by a single
organization comprising multiple consumers (for example, business
units). It may be owned, managed, and operated by the organization,
a third party, or some combination of them, and it may exist on or off
premises.” – NIST

Many organizations may not want to adopt public clouds due to concerns
related to privacy, external threats, and lack of control over the IT resources and
data
 When compared to a public cloud, a private cloud offers organizations a
greater degree of privacy and control over the cloud infrastructure,
applications, and data

There are two variants of private cloud: on-premise and externally hosted
 An organization deploys on-premise private cloud in its data center within its
own premises
Enterprise P
Resources of Cloud
Provider
1. On-premise Private Cloud
Enterprise P
Resources of
Enterprise P
Dedicated for
Enterprise P
2. Externally Hosted Private Cloud
Application
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 43
Cloud Computing Lesson
Notes
In the externally hosted private cloud (or off-premise private cloud) model:

An organization outsources the implementation of the private cloud to an
external cloud service provider

The cloud infrastructure is hosted on the premises of the provider and multiple
tenants may share
 However, the organization’s private cloud resources are securely separated
from other cloud tenants by access policies implemented by the provider
Information Storage and Management (ISM) v4
Page 44
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Community Cloud
Definition: Community Cloud
“The cloud infrastructure is provisioned for exclusive use by a specific
community of consumers from organizations that have shared
concerns (for example, mission, security requirements, policy, and
compliance considerations). It may be owned, managed, and
operated by one or more of the organizations in the community, a
third party, or some combination of them, and it may exist on or off
premises.” – NIST

The organizations participating in the community cloud typically share the cost
of deploying the cloud and offering cloud services
 This enables them to lower their individual investments

Since the costs are shared by a fewer consumer than in a public cloud, this
option may be more expensive

However, a community cloud may offer a higher level of control and protection
than a public cloud

There are two variants of a community cloud: on-premise and externally hosted
Enterprise P
Enterprise Q
Enterprise R
Community
Users
Resources of Cloud
Provider
Dedicated for
Community
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 45
Cloud Computing Lesson
Information Storage and Management (ISM) v4
Page 46
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
Hybrid Cloud
Definition: Hybrid Cloud
“The cloud infrastructure is a composition of two or more distinct cloud
infrastructures (private, community, or public) that remain unique
entities, but are bound by standardized or proprietary technology that
enables data and application portability (for example, cloud bursting
for load balancing between clouds.)” – NIST
Enterprise Q
Public
Enterprise P
Private
Individual R
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 47
Cloud Computing Lesson
Evolution of Hybrid Cloud: Multicloud

To create the best possible solution for their businesses, today organizations
want to choose different public cloud service providers

To achieve this goal, some organizations have started adopting a multicloud
approach
Public Cloud
Private Cloud
Public Cloud
Notes
The drivers for adopting this approach include avoiding vendor lock-in, data control,
cost savings, and performance optimization. This approach helps to meet the
business demands since, sometimes no single cloud model can suit the varied
requirements and workloads across an organization. Some application workloads
run better on one cloud platform while other workloads achieve higher performance
and lower cost on another platform.
Also, certain compliance, regulation, and governance policies require an
organization’s data to reside in particular locations. A multicloud strategy can help
organizations meet those requirements because different cloud models from
Information Storage and Management (ISM) v4
Page 48
© Copyright 2019 Dell Inc.
Cloud Computing Lesson
various cloud service providers can be selected. Each cloud vendor offers different
service options at different prices.
Organizations can also analyze the performance of their various application
workloads and compare them to what is available from other vendors. This method
helps to analyze both workload performance and cost for various services in each
cloud. Options can then be identified that meet the workload performance and cost
requirements of the organization.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 49
Cloud Computing Lesson
Cloud Computing Use Cases
Use Case
Description
Cloud bursting
Provisioning resources for a limited time from a public
cloud to handle peak workloads
Web application
hosting
Hosting less critical applications on the public cloud
Migrating packaged
applications
Migrating standard packaged applications such as e-mail
to the public cloud
Application
development and
testing
Developing and testing applications in the public cloud
before launching them
Big Data Analytics
Using cloud to analyze the voluminous data to gain
insights and for deriving business value
Disaster Recovery
Adopting cloud for a DR solution can provide cost benefit,
scalability and faster recovery of data
Internet of Things
IoT in cloud provides infrastructure for enhancing the
network connectivity, storage space, and tools for data
analysis
Information Storage and Management (ISM) v4
Page 50
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
Big Data Analytics Lesson
Introduction
This lesson presents an overview of Big Data along with its characteristics, data
repositories, components of big data analytics solution, and uses cases.
This lesson covers the following topics:

Big Data and its key characteristics

Data repositories

Components of Big Data analytics solution

Use cases of Big Data
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 51
Big Data Analytics Lesson
Big Data Analytics
Big Data: An Overview
Definition: Big Data
Information assets whose high volume, high velocity, and high variety
require the use of new technical architectures and analytical methods
to gain insights and for deriving business value.
Characteristics of Data
Data Processing Nodes
Business Value
Big Data
Big Data:

Represents the information assets whose high volume, high velocity, and high
variety require the use of new technical architectures and analytical methods to
gain insights and for deriving business value.

Many organizations such as government departments, retail,
telecommunications, healthcare, social networks, banks, and insurance
companies employ data science techniques to benefit from Big Data analytics.
The definition of Big Data has three principal aspects, which are:
Information Storage and Management (ISM) v4
Page 52
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
Characteristics of Data
Big Data includes data sets of considerable sizes containing both structured and
non-structured digital data. Apart from its size, the data gets generated and
changes rapidly, and also comes from diverse sources. These and other
characteristics are covered next.
Data Processing Needs
Big Data also exceeds the storage and processing capability of conventional IT
infrastructure and software systems. It not only needs a highly-scalable architecture
for efficient storage, but also requires new and innovative technologies and
methods for processing.
These technologies typically make use of platforms such as distributed processing,
massively-parallel processing, and machine learning. The emerging discipline of
Data Science represents the synthesis of several existing disciplines, such as
statistics, mathematics, data visualization, and computer science for Big Data
analytics.
Business Value
Big Data analytics has tremendous business importance to organizations.
Searching, aggregating, and cross-referencing large data sets in real-time or nearreal time enables gaining valuable insights from the data. This enables better datadriven decision making.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 53
Big Data Analytics Lesson
Characteristics of Big Data
Apart from the characteristics of volume, velocity, and variety—popularly known as
“the 3V’s, the three other characteristics of Big Data include variability, veracity,
and value
Volume
Velocity
Variety
Variability
Veracity
Value
• Costeffectiveness and
business value
• Massive volumes
of data
• Rapidly
changing data
• Diverse data
from numerous
sources
• Constantly
changing meaning
of data
• Varying quality
and reliability of
data
• Challenges in
storage and
analysis
• Challenges in
real-time analysis
• Challenges in
integration, and
analysis
• Challenges in
gathering and
interpretation
• Challenges in
transforming and
trusting data
Notes

Volume: The word “Big” in Big Data refers to the massive volumes of data.
Organizations are witnessing an ever-increasing growth in data of all types.
These types include transaction-based data that is stored over the years,
sensor data, and unstructured data streaming in from social media. The volume
of data has already reached Petabyte and Exabyte scales, and it is still growing
everyday. The excessive volume not only requires substantial cost-effective
storage, but also rises challenges in data analysis.

Velocity: Velocity refers to the rate at which data is produced and changes, and
also how fast the data must be processed to meet business requirements.
Today, data is generated at an exceptional speed, and real-time or near-real
time analysis of the data is a challenge for many organizations. It is essential to
process and analyze the data, and to deliver the results in a timely manner. An
example of such a requirement is real-time face recognition for screening
passengers at airports.

Variety: Variety refers to the diversity in the formats and types of data. There
are numerous sources that generate data in various structured and unstructured
forms. Organizations face the challenge of managing, merging, and analyzing
Information Storage and Management (ISM) v4
Page 54
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
the different varieties of data in a cost-effective manner. The combination of
data from a variety of data sources and in a variety of formats is a key
requirement in Big Data analytics. An example of such a requirement could be
an autonomous vehicle dealing with various data formats and sources to
operate safely.

Variability: Variability refers to the constantly changing meaning of data. It
highlights the importance of deriving the right information at all possible
contexts. For example, analysis of natural language search and social media
posts requires interpretation of complex and highly variable grammar. The
inconsistency in the meaning of data creates challenges that are related to
gathering the data and in interpreting its context.

Veracity: Veracity refers to the reliability and verifiability of the data. The quality
of the data being gathered can differ greatly, and the accuracy of analysis
depends on the veracity of the source data. Establishing trust in Big Data
presents a major challenge because as the variety and number of sources
grows, the likelihood of noise and errors in the data increases. Therefore,
significant effort may go into cleaning data to remove noise and errors, and to
produce accurate datasets before analysis can begin. For example, a retail
organization may have gathered customer behavior data from across systems
to analyze product purchase patterns and to predict purchase intent. The
organization would have to clean and transform the data to make it consistent
and reliable.

Value: Value refers to the cost-effectiveness of the Big Data analytics
technology that is used and the business value that is derived from it. Many
large enterprise scale organizations have maintained large data repositories,
such as data warehouses, managed unstructured data, and carried out realtime data analytics for many years. With hardware and software becoming more
affordable and the emergence of more providers, Big Data analytics
technologies are now available to a broader market. Organizations are also
gaining the benefits of business process enhancements, increased revenues,
and better decision making.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 55
Big Data Analytics Lesson
Data Repositories
Data Warehouses
Data Lake
• Central repository of data
gathered from different sources
• Collection of structured and
unstructured data assets
Data Repositories
• Stores current and historical
data in a structured format
• Designed for query and analysis
• Uses 'store everything'
approach to big data
• Presents unrefined view of
data
Notes
Data for analytics typically comes from repositories such as enterprise data
warehouses and data lakes.
A data warehouse is a central repository of integrated data that is gathered from
multiple different sources. It stores current and historical data in a structured
format. It is designed for query and analysis to support the decision-making
process of an organization. For example, a data warehouse may contain current
and historical sales data that is used for generating trend reports for sales
comparisons.
A data lake is a collection of structured and unstructured data assets that are
stored as exact or near-exact copies of the source formats. The data lake
architecture is a “store-everything” approach to Big Data. Unlike conventional data
warehouses, you do not classify the data when it is stored in the repository, as the
value of the data may not be clear at the outset. The data is also not arranged as
per a specific schema and is stored using an object-based storage architecture. As
a result, data preparation is eliminated and a data lake is less structured compared
to a data warehouse. Data is classified, organized, or analyzed only when it is
accessed. When a business need arises, the data lake is queried, and the resultant
subset of data is then analyzed to provide a solution. The purpose of a data lake is
to present an unrefined view of data to highly skilled analysts. Also to enable them
to implement their own data refinement and analysis techniques.
Information Storage and Management (ISM) v4
Page 56
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 57
Big Data Analytics Lesson
Components of a Big Data Analytics

The technology layers in a Big Data analytics solution include storage plus
MapReduce and query technologies

These components are collectively called the ‘SMAQ stack’
 SMAQ solutions may be implemented as a combination of multi-component
systems

May also be offered as a product with a self-contained system comprising
storage, MapReduce, and query – all in one
• Foundational layer of the stack
Storage
• Distributed architecture
• Enables distribution of computation
MapReduce
• Uses multiple compute systems for parallel processing
• Implements NoSQL database
Query
• Provides platform for analytics and reporting
Notes
The technology layers in a Big Data analytics solution include storage, MapReduce
technologies, and query technologies. These components are collectively called
the ‘SMAQ stack’.

Storage: It is the foundational layer of the stack, and has a distributed
architecture characteristic with primarily unstructured content in non-relational
form.
Information Storage and Management (ISM) v4
Page 58
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson

MapReduce: It is an intermediate layer in the stack. It enables the distribution
of computation across multiple generic compute systems for parallel processing
to gain speed and cost advantage. It also supports a batch-oriented processing
model of data retrieval and computation as opposed to the record-set
orientation of most SQL-based databases.

Query: This layer typically implements a NoSQL database for storing,
retrieving, and processing data. It also provides a user-friendly platform for
analytics and reporting.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 59
Big Data Analytics Lesson
Storage

Storage systems consist of multiple nodes that are collectively called a “cluster”
 Based on distributed file systems
 Each node has processing capability and storage capacity
 Highly scalable architecture

You may implement a NoSQL database on top of the distributed file system
Notes
A storage system in the SMAQ stack is based on either a proprietary or an opensource distributed file system, such as Hadoop Distributed File System (HDFS).
The storage system may also support multiple file systems for client access. The
storage system consists of multiple nodes—collectively called a “cluster”—, and the
file system is distributed across all the nodes in the cluster. Each node in the
cluster has processing capability and storage capacity. The system has a highly
scalable architecture, and you can add extra nodes dynamically to meet the
workload and the capacity needs.
The distributed file system like HDFS typically provides only an interface similar to
that of regular file systems. Unlike a database, they can only store and retrieve
data and not index it, which is essential for fast data retrieval. To mitigate this
challenge and gain the advantages of a database system, SMAQ solutions may
implement a NoSQL database on top of the distributed file system. NoSQL
databases may have built-in MapReduce features that enable processing to be
parallelized over their data stores. In many applications, the primary source of data
is in a relational database. Therefore, SMAQ solutions may also support the
interfacing of MapReduce with relational database systems.
MapReduce fetches datasets and stores the results of the computation in storage.
The data must be available in a distributed fashion, to serve each processing node.
The design and features of the storage layer are important not just because of the
interface with MapReduce, but also because they affect the ease with which data
can be loaded and the results of computation extracted and searched.
Information Storage and Management (ISM) v4
Page 60
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
MapReduce

MapReduce is the driving force behind most Big Data processing solutions
 A parallel programming framework for processing large datasets on a
compute cluster

The key innovation of MapReduce is the ability to take a query over a dataset,
divide it, and run it in parallel over multiple compute systems or nodes
 This distribution solves the issue of processing data that is too large for a
single machine to process
Notes
MapReduce is the driving force behind most Big Data processing solutions. It is a
parallel programming framework for processing large datasets on a compute
cluster. The key innovation of MapReduce is the ability to take a query over a
dataset, divide it, and run it in parallel over multiple compute systems or nodes.
This distribution solves the issue of processing data that is too large for a single
machine to process.
MapReduce works in two phases namely ‘Map’ and ‘Reduce’ as the name
suggests. An input dataset is split into independent chunks which are distributed to
multiple compute systems. The Map function processes the chunks in a parallel
manner, and transforms them into multiple smaller intermediate datasets. The
Reduce function condenses the intermediate results and reduces them to a
summarized dataset, which is the wanted end result. Typically both the input and
the output datasets are stored on a file-system. The MapReduce framework is
highly scalable and supports the addition of processing nodes to process chunks.
Apache’s Hadoop MapReduce is the predominant open source Java-based
implementation of MapReduce.
The illustration depicts a generic representation of how MapReduce works. You
can use this illustration to show various examples. A classic example of
MapReduce is the task of counting the number of unique words in a large body of
data including millions of documents. In the Map phase, each word is identified and
given the count of 1. In the Reduce phase, the counts are added for each word.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 61
Big Data Analytics Lesson
Another example is the task of grouping customer records within a dataset into
multiple age groups, such as 20- 30, 30- 40, 40- 50, and so on. In the Map phase,
you split the records and process in parallel to generate intermediate groups of
records. In the Reduce phase, you summarize the intermediate datasets to obtain
the distinct groups of customer records (depicted in the colored groups).
Information Storage and Management (ISM) v4
Page 62
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
MapReduce Example

A classic example of MapReduce is the task of counting the number of unique
words in a large body of data including millions of documents
 In the Map phase, each word is identified and given the count of 1
 In the Reduce phase, the counts are added for each word

Another example is the task of grouping customer records within a dataset into
multiple age groups, such as 20- 30, 30- 40, 40- 50, and so on.
 In the Map phase, you split the records and process in parallel to generate
intermediate groups of records
 In the Reduce phase, you summarize the intermediate datasets to obtain the
distinct groups of customer records

The illustration depicts a generic representation of how MapReduce works; it
can be used to represent various examples
Input Data
Output Data
Map Phase
Reduce Phase
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 63
Big Data Analytics Lesson
Query

Simplifies the specification of MapReduce operations, and the retrieval and
analysis of the results

It is non-intuitive and inconvenient to specify MapReduce jobs in terms of
distinct Map and Reduce functions in a programming language
 SMAQ systems help mitigate this challenge by incorporating a higher-level
query layer to simplify both the:
o Specification of the MapReduce operations
o Analysis of the results

Query layer implements high-level languages that enable users to describe, run,
and monitor MapReduce jobs
 Languages are designed to handle not only the processing, but also the
loading and saving of data from and to the MapReduce cluster
 Languages typically support integration with NoSQL databases that you
implement on the MapReduce cluster
Information Storage and Management (ISM) v4
Page 64
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
Big Data Use Cases
Use Case
Description
Healthcare
Provides consolidated diagnostic information and improves
patient care
Finance
Effective sales promotion and fraud detection
Retail and
eCommerce
Understand customer buying patterns, and anticipate future
demand
Government
Improves efficiency and effectiveness across various
domains
Social Network
Analysis
Discovery and analysis of communities, personalization of
solitary, and social activities
Gaming
Improves revenue of gaming industry and gaming
experience
Geolocation
Services
Improves service, customer experience, and to gain
competitive advantage
Notes

Healthcare: In healthcare, Big Data analytics solutions provide consolidated
diagnostic information and enable healthcare providers to analyze patient data;
improve patient care and outcomes; minimize errors; increase patient
engagement; and improve operations and services. These solutions also enable
healthcare providers to monitor patients and analyze their experiences in real
time.

Finance: In finance, organizations use Big Data analytics for activities such as
correlating purchase history, profiling customers, and analyzing behavior on
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 65
Big Data Analytics Lesson
social networks. This also enables in controlling customer acquisition costs and
target sales promotions more effectively. Big Data analytics is also being used
extensively in detecting credit card frauds.

eCommerce: eCommerce organizations use Big Data analytics to gain
valuable insights from the data. They use this solution to understand customer
buying patterns, and anticipate future demand. Also for effective marketing
campaigns, optimize inventory assortment, and improve distribution. This
solution enables them to provide optimal prices and services to customers, and
also improve operations and revenue.

Government: In government organizations, Big data analytics enables
improved efficiency and effectiveness across a variety of domains such as
social services, education, defense, national security, crime prevention,
transportation, tax compliance, and revenue management.

Social Network Analysis: The increasing use of online social networking
services has led to a massive growth of data in the digital universe. Through Big
Data analytics, organizations can gain valuable insights from the data that is
generated through social networking. This analysis enables the discovery and
analysis of communities, personalization for solitary activities (for example,
search) and social activities (for example, discovery of potential friends). It also
involves the analysis of user behavior in open forums (for example,
conventional sites, blogs, and communities) and in commercial platforms (for
example, eCommerce).

Gaming: Big Data plays a very important role in gaming industry due to billions
of video game players in the world. Gamers are generating a massive amount
of data through offline and online games. There are many factors that contribute
to the rapid growth of data in the gaming industry. These factors include what
game the gamers play and with whom they play, advertisements, and real time
information of the gamer. These industries use Big Data technologies to
improve their revenue and gaming experience.

Geolocation Services: Businesses like finance, social media, retailers, and
transport are using geolocation services in their applications to locate their
customers. This service generates a huge amount of data which requires them
to use Big Data algorithms to derive a meaning information. Businesses are
using this information to improve their service, customer experience, and to gain
competitive advantage.
Information Storage and Management (ISM) v4
Page 66
© Copyright 2019 Dell Inc.
Big Data Analytics Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 67
Internet of Things Lesson
Internet of Things Lesson
Introduction
This lesson presents an overview of the Internet of Things (IoT) along with its
components and protocols used. It also focuses on the impact of IoT on data center
and its use cases.
This lesson covers the following topics:

Internet of Things and its components

Use cases of Internet of Things
Information Storage and Management (ISM) v4
Page 68
© Copyright 2019 Dell Inc.
Internet of Things Lesson
Internet of Things
Internet of Things: An Overview
Concept of networking objects and people for real time
applications
Allow real-life objects to independently share and process
information
Internet of Things
Enable Machine to Machine communication to provide real
time results
Notes
In this rapidly transforming digital landscape, the speed of communication has
become a necessary metric for every organization to access their information. The
evolution of Internet and the rise of devices that are connected to Internet provide
new opportunities for smarter decision making, getting a competitive edge, and to
improve the life of customers. These devices range from laptops, mobiles phones
to irrigation systems to cars generating digital data.
The Internet of Things (IoT) is the concept of networking things such as objects and
people to collect and exchange data. The idea is that real-life objects can
independently share and process information - without humans having anything to
do with the data input stage.
IoT supports Machine to Machine (M2M) communication enabling devices to
communicate with each other to provide faster, accurate, and timely data-driven
results. The use of IoT requires organizations to store large volumes of data, and to
process and analyze data in real time. It also requires a transformation in data
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 69
Internet of Things Lesson
center to meet the network, security, and data storage and management
requirements.
Information Storage and Management (ISM) v4
Page 70
© Copyright 2019 Dell Inc.
Internet of Things Lesson
Components of Internet of Things

IoT implementation requires a proper understanding of its components
Actuators
Sensors
Gateways
Detect changes in the
surrounding environment
Collect data from sensors to
perform required action
Manage data traffic and
translate network protocols
Produce and transmit digital
data
In IoT, they help to automate
the operations
Ensure that the devices are
interoperable
IoT Example: Modern Irrigation System

IoT devices are used to monitor the crop field and automate the irrigation
system to increase the efficiency and productivity of the overall agricultural
processes.

Soil moisture sensors detect the moisture levels in the soil and send the
appropriate data to the actuator

Based on the data, the actuator device will control the flow of water through the
valves

Since these devices generate a lot of data, gateways help to transfer this data
to the cloud for storage
– Gateways communicate with sensors using various protocols and translate
the data that is appropriate for cloud transmission.
Notes
The main components include:

Sensors: Smart devices that detect changes in their surrounding environment,
produce, and transmit digital data. Sensors should be able to detect a wide
range of physical phenomenon ranging from temperature, pressure, to motion
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 71
Internet of Things Lesson
and magnetic fields. Examples of sensors include thermostats, moisture
sensors, accelerometer, gas/smoke sensors and so on. In IoT, different sensors
are used for different IoT applications to produce and transfer the data for
processing.

Actuators: Devices that collect data from sensors and perform the required
action. Actuators consume energy to produce physical action like creating a
motion or controlling a system. Examples of actuators include electric motor that
uses electric power to generate motion, hydraulic actuators use fluid pressure to
generate motion. In IoT, actuators help to automate the operations by applying
a force based on the dynamics of data generated by sensors.

Gateways: IoT involves billions of devices that are on various networks getting
connected for data communication. Gateways are devices that manage data
traffic between networks by translating their network protocols. This process
ensures that devices operating in various networks are interoperable. In IoT,
these gateway devices can also be designed to analyze and secure the data
that are collected from sensors before transmitting it to the next phase.
Information Storage and Management (ISM) v4
Page 72
© Copyright 2019 Dell Inc.
Internet of Things Lesson
Internet of Things Use Cases
Use Case
Description
Home Automation
Allows home owners to monitor and control home appliances
anytime irrespective of the location
Smart Cities
Highlights the need to enhance the quality of life of the
citizens using IoT
Wearables
Helps to collect data about the users health. Also helps to
detect and report crimes
Manufacturing
Industries
Helps industries to identify optimization possibilities in their
day to day operations
Notes

Home Automation: The use of IoT has entered the residential environment with
the introduction of smart home technology. Various electronic objects at home
such as air conditioner, lights, refrigerators, security cameras, kitchen stoves
can be connected to the Internet with the help of sensors. This will allow the
home owners to efficiently monitor and control the objects anytime irrespective
of the location.

Smart Cities: The smart cities concept highlights the need to enhance the
quality of life of the citizens using smart public infrastructure. This process
enables optimization of power usage, efficient water supply, manage waste
collections, reliable public transportation using IoT sensors. All these data will
collected and sent to a control center which directs the necessary actions. This
application of IoT can also be extended to build smarter environment by early
detection of earthquake, air pollution, and forest fire.

Wearables: With the use of wearables and embedded devices on people, IoT
sensors can collect data about the users regarding their health, heartbeat, and
exercise patterns. For example, embedded chips enable doctors to monitor
patients who are in critical care, by tracking and charting all their vital signs
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 73
Internet of Things Lesson
constantly. Wearables also have their application in detecting and reporting
crimes in the city.

Manufacturing Industries: Using IoT in manufacturing industries is helping them
to identify optimization possibilities in their day to day operations. By applying
IoT, they are not just able to monitor but they are also able to automate the
complex tasks involved.
Information Storage and Management (ISM) v4
Page 74
© Copyright 2019 Dell Inc.
Machine Learning Lesson
Machine Learning Lesson
Introduction
This lesson presents an overview of machine learning and the different types of
machine learning algorithms. It focuses on the impact of machine learning on data
center, and its use cases.
This lesson covers the following topics:

Overview of Machine Learning

Types of Machine Learning Algorithms

Impact of Machine Learning on the Data Center

Use cases of Machine Learning
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 75
Machine Learning Lesson
Machine Learning
Machine Learning (ML) Overview

Automation can provide faster, better, and deeper data insights

Intelligent machines are being built to automatically learn from data and to make
decisions
– Intelligent machines help to process the data in real time
Artificial Intelligence
Machine Learning
Deep Learning
Notes
Artificial intelligence, machine learning, and deep learning are three intertwined
concepts that help to build this human-like ability into computer systems. Artificial
Intelligence (AI) is an umbrella term, while machine and deep learning are the
techniques that make AI possible. AI is a technology of creating intelligent systems
that work and think like humans.
Machine learning refers to the process of ‘training’ the machine, feeding large
amounts of data into algorithms that give it the ability to learn how to perform the
Information Storage and Management (ISM) v4
Page 76
© Copyright 2019 Dell Inc.
Machine Learning Lesson
task without being explicitly programmed. Instead of writing a program, a machine
is provided with data. With the help of algorithms, machines learn from the data
and complete a specific task. When the machine is provided with a new dataset, it
adapts to it by learning from previous experiences to produce reliable outputs.
Deep learning is a machine learning technique that uses neural networks as the
underlying architecture for training models. Fast compute and storage with a lot of
memory and high-bandwidth networking will enable machine to learn faster and
provide accurate results. Neural networks is a set of algorithms that are used to
establish relationships in a dataset by imitating a human brain. A training model is
an object which is provided with an algorithm along with a set of data from which it
can learn.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 77
Machine Learning Lesson
Algorithm Types

A machine learning process involves creating mathematical and statistical
algorithms that can accept input data and use some sort of analysis to predict
the output
 In this process, the first step is to collect the datasets for analysis.

Once the data is collected, select the type of algorithm to be used, then build a
model.
 Train the model with test data sets, and improvise the model accordingly for
future decision making
 Most machine learning algorithms can be classified into the following three
types:
Supervised Learning
Unsupervised Learning
Reinforcement Learning
Models are trained to predict future
events
Models are left to discover the
information
Algorithms/models interacts with their
environment
Algorithms try to find patterns using
labeled dataset
Algorithms uses unlabeled data and try
to find similarities/differences
Produces results based on trial and
error method
Inputs and outputs can be clearly
defined
Only input data is given and output data
is not available
Uses rewards and errors as feedback to
learn
Notes

Supervised Learning: Models are trained to predict future events by learning
from previous datasets. In supervised learning, you teach the models by training
them on a labelled data set. The algorithm then tries to find patterns in the data
to predict events on new data sets. This labeled dataset includes attributes
(properties) and observations (values). This type of learning is used when the
inputs and outputs can be clearly identified. The learning algorithm can
compare its predictions with the correct output. If any errors are recognized,
they have the capability to correct themselves and improvise the model
accordingly.
Information Storage and Management (ISM) v4
Page 78
© Copyright 2019 Dell Inc.
Machine Learning Lesson
 Example: A dataset consists of bikes and cars. The machine is trained by
providing the features of each. A bike has 2 wheels, and a car has four
wheels. Now, when the machine is provided with a new dataset, the
machine can identify either of them based on the previous experience.

Unsupervised Learning: Models are left to discover the information/structure
that is hidden in the unlabeled data. This type of learning is used when only the
input data is available and there is no output data. The model itself has to
identify the output by grouping the unlabeled data by similarities or differences
without any prior training.
 Example: A machine is provided with an image having dogs and cats in it
without specifying either the dog feature or the cat feature. The machine
categorizes them by comparing the similarities and differences into two
groups. One group having all dogs in it and the second group having all cats
in it.

Reinforcement Learning: The learning algorithm is enabled to interact with its
environment and produce results based on a trial and error method. The model
continues to train itself with the help of rewards and errors feedback. The
machine depends on both learning from the previous feedback, and discovers
the new strategy to complete a specific task. By determining which action
results in greater rewards, the output results are produced and this is how the
machine maximizes its performance.
 Example: Reinforcement learning is similar to playing video games, when a
gamer completes a level, he will be rewarded, and if he is unable to
complete over a certain number of chances, the game will be over. Now, the
gamer has to make new strategies based on the previous game experience
to improve his performance.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 79
Machine Learning Lesson
Impact on the Data Center

Improves efficiency of the data center and its management

Helps to identify security issues which would otherwise become challenging
using manual operations

Requires sufficient storage capacity to manage and store datasets

Requires high-end microprocessors and modern storage solution
Notes
Artificial Intelligence and
Machine Learning are providing
new opportunities for the data
center as well as creating
challenges if organizations are
not prepared to support these
technologies from their
infrastructure aspect.
Machine learning helps in
making the data center and its management efficient by reducing energy usage,
maximizing usage and operation of resources, automating operations, and
preventing downtime.
Machine learning algorithms can be applied to data logs collected from
infrastructure resources to identify any problems or security issues that would
otherwise become challenging using manual operations. As this operational data
log becomes a larger dataset for machine learning systems, it requires sufficient
storage capacity to efficiently manage and store.
Machine learning applications require high-end microprocessors for faster
processing of data and modern storage solutions to keep up with the processing
speed. Organizations can consider using hybrid cloud storage options for reducing
the data center footprint, load-balancing, and cost-effectiveness.
Information Storage and Management (ISM) v4
Page 80
© Copyright 2019 Dell Inc.
Machine Learning Lesson
Machine Learning Use Cases
Use Case
Description
Energy
A large amount of data that is generated by this industry is
processed using machine learning solutions to increase their
productivity. It helps to efficiently use energy storage by
tracking the usage. Handles different types of energy
sources using autonomous grids. It also helps to predict
component failures and consumption demand.
Media and
Entertainment
Content from the media and entertainment industry can be
automatically tagged using metadata by applying machine
learning solutions. This method enhances content-based
search activity by finding the right content quickly and helps
the content developers to optimize the content to specific
audiences based on their search data. It also plays an
important role in creating video subtitles using natural
language processing.
Sports
Machine learning can be applied to sports in predicting the
results of the games, helps coaches to get insights into the
players performance and to better organize the games with
appropriate strategy by analyzing the performance and game
data.
Financial Services
Banks and other businesses use machine learning to detect
and prevent fraudulent activities for credit cards and bank
accounts. It also helps to identify investment opportunities for
traders by monitoring market changes. It is used to provide
risk management solutions like predicting financial crisis,
loan repayment capabilities of the customers, and securing
financial data.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 81
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC Cloud for Microsoft Azure,

Dell EMC Ready Solution for Artificial Intelligence

Dell Edge Gateway

VMware Cloud on AWS

Pivotal Cloud Foundry
Information Storage and Management (ISM) v4
Page 82
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
Dell EMC Cloud for Microsoft Azure
Delivers Infrastructure and Platform as a Service with a consistent Azure
experience on-premises and in the public cloud. This platform is built on VxRack
AS hyper-converged architecture that has modular building blocks that are called
nodes and powered by Microsoft Windows software-defined storage and
networking capabilities. It is managed using Microsoft Azure Stack interface. Cloud
for Microsoft Azure Stack provides a simple, cost-effective solution that delivers
multiple performance and capacity options to match any use case and covers a
wide variety of cloud-native applications and workloads.
Pivotal Cloud Foundry
An enterprise Platform as a Service solution, which is built on the foundation of the
Cloud Foundry open-source PaaS project. Pivotal CF, powered by Cloud Foundry,
enables streamlined application development, deployment, and operations in both
private and public clouds. It supports multiple programming languages and
frameworks. It helps developers to deploy their applications without being
concerned about configuring and managing the underlying cloud infrastructure. It
provides zero downtime stack updates while migrating the applications to the new
stack. Developers can use the security controls offered by PCF.
Dell Edge Gateway
An intelligent device that is designed to aggregate, secure, analyze, and relay data
from diverse sensors and equipment at the edge of the network. These gateways
bridge both legacy systems and modern sensors to the internet, helping to get
business insights from the real-time, pervasive data in your machines and
equipment. It is compact, consumes less power, and suitable for challenging field
and mobile use cases. It is designed for flexible manageability using Dell Edge
Device Manager or a third-party on-premise console.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 83
Concepts in Practice Lesson
Dell EMC Ready Solution for Artificial Intelligence
These solutions shorten the deployment time from months to days. They include
software that streamlines the set‑ up of data science environments to just a few
clicks, boosting data scientist productivity. These solutions are optimized with
software, servers, networking, storage, and services to help organizations to get
faster and deeper insights. These solutions include:

Dell EMC Machine Learning with Hadoop: Builds on the power of tested and
proven Dell EMC Ready Bundles for Hadoop, created in partnership with
Cloudera®. This solution includes an optimized solution stack along with data
science and framework optimization. It consists of Cloudera Data Science
Workbench with the added ease of a Dell EMC Data Science Engine

Dell EMC Deep Learning with Intel: Simplifies and accelerates the adoption of
deep learning technology with an optimized solution stack that simplifies the
entire workflow from model building to training to inferencing. It consists of
PowerEdge C servers and Dell EMC H-series networking based on Intel OmniPath networking.

Dell EMC Deep Learning with NVIDIA: Provides a GPU‑ optimized solution
stack that can shave valuable time from deep learning projects. It consists of
PowerEdge servers with NVIDIA GPUs and Isilon Scale-out NAS storage.
VMware Cloud on AWS
Extends the VMware Software Defined Data Center (SDDC) software onto the
AWS cloud. This SDDC software consists of several other products including
vCenter Server for data center management, vSAN for software-defined storage,
and NSX for software-defined networking. It enables customers to run their
VMware vSphere based applications across private, public, and hybrid cloud
environments with optimized access to AWS services. It helps virtual machines in
SDDC to access AWS EC2 and S3 services. This solution provides workload
migration, allows customers to use the global presence of AWS data centers, and
flexibility of management.
Information Storage and Management (ISM) v4
Page 84
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. What is a machine learning technique that uses neural networks as the
underlying architecture for training models?
A. Deep learning
B. Bigdata analytics
C. Edge computing
D. Internet of Things
2. Identify the cloud computing characteristic that controls and optimizes resource
use by leveraging a metering capability.
A. Measured services
B. On-demand self service
C. Resource pooling
D. Rapid elasticity
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 85
Summary
Summary
Information Storage and Management (ISM) v4
Page 86
© Copyright 2019 Dell Inc.
Modern Data Center Environment
Introduction
This module focuses on the compute system, its components, and its types. This
module also focuses on compute virtualization and application virtualization.
Further, this module focuses on an overview of storage and connectivity in a data
center. Finally, this module focuses on an overview of software-defined data
center.
Upon completing this module, you will be able to:
 Describe a compute system, its components, and its types
 Describe compute virtualization, desktop virtualization, and application
virtualization
 Provide an overview of storage and connectivity in a data center
 Provide an overview of software-defined data center
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 87
Compute System Lesson
Compute System Lesson
Introduction
This lesson covers compute system, and its key physical and logical components.
This lesson also covers the types of compute systems.
This lesson covers the following topics:

Explain physical and logical components of a compute system

Explain types of compute systems
Information Storage and Management (ISM) v4
Page 88
© Copyright 2019 Dell Inc.
Compute System Lesson
Compute System
What is a Compute System?

A computing platform (hardware and system software) that runs applications
 Physical components include processor, memory, internal storage, and I/O
devices
 Logical components include OS, device drivers, file system, and logical
volume manager
Compute System
Notes
A compute system is a computing device (combination of hardware, firmware, and
system software) that runs business applications.
Examples of compute systems include physical servers, desktops, laptops, and
mobile devices. The term compute system refers to physical servers and hosts on
which platform software, management software, and business applications of an
organization are deployed.
A compute system’s hardware consists of processor(s), memory, internal storage,
and I/O devices. The logical components of a compute system include the
operating system (OS), file system, logical volume manager, and device drivers.
The OS may include the other software, or they can be installed individually.
In an enterprise data center, applications are typically deployed on compute
clusters for high availability and for balancing computing workloads. A compute
cluster is a group of two or more compute systems that function together, sharing
certain network and storage resources, and logically viewed as a single system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 89
Compute System Lesson
Information Storage and Management (ISM) v4
Page 90
© Copyright 2019 Dell Inc.
Compute System Lesson
Types of Compute Systems
The compute systems used in building data centers are typically classified into
three categories: tower compute system, rack-mounted compute system, and blade
compute system
Rack-mounted Compute System
Blade Compute System
Tower Compute System
Tower
A tower compute system, also known as a tower server, is a compute system built
in an upright stand-alone enclosure called a “tower”, which looks similar to a
desktop cabinet. Tower servers have a robust build, and have integrated power
supply and cooling. They typically have individual monitors, keyboards, and mice.
Tower servers occupy significant floor space and require complex cabling when
deployed in a data center. They are also bulky, and a group of tower servers
generate considerable noise from their cooling units. Tower servers are typically
used in smaller environments. Deploying many tower servers in large environments
may involve substantial expenditure.
Rack-mounted
A rack-mounted compute system, also known as a rack server, is a compute
system designed to be fixed inside a frame called a “rack”. A rack is a standardized
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 91
Compute System Lesson
enclosure containing multiple mounting slots called “bays”, each of which holds a
server in place with the help of screws. A single rack contains multiple servers
stacked vertically in bays, thereby simplifying network cabling, consolidating
network equipment, and reducing the floor space use. Each rack server has its own
power supply and cooling unit. Typically, a console is mounted on a rack to enable
administrators to manage all the servers in the rack.
Some concerns with rack servers are that they are cumbersome to work with, and
they generate many heat because of which more cooling is required, which in turn
increases power costs. A “rack unit” (denoted by U or RU) is a unit of measure of
the height of a server designed to be mounted on a rack. One rack unit is 1.75
inches (44.45 mm). A 1 U rack server is typically 19 inches (482.6 mm) wide.
The standard rack cabinets are 19 inches wide and the common rack cabinet sizes
are 42U, 37U, and 27U. The rack cabinets are also used to house network,
storage, telecommunication, and other equipment modules. A rack cabinet may
also contain a combination of different types of equipment modules.
Blade
A blade compute system, also known as a blade server, is an electronic circuit
board containing only core processing components, such as processor(s), memory,
integrated network controllers, storage drive, and essential I/O cards and ports.
Each blade server is a self-contained compute system and is typically dedicated to
a single application.
A blade server is housed in a slot inside a blade enclosure (or chassis), which
holds multiple blades and provides integrated power supply, cooling, networking,
and management functions. The blade enclosure enables interconnection of the
blades through a high-speed bus and also provides connectivity to external storage
systems.
The modular design of the blade servers makes them smaller, which minimizes the
floor space requirements, increases the compute system density and scalability,
and provides better energy efficiency as compared to the tower and the rack
servers. It also reduces the complexity of the compute infrastructure and simplifies
compute infrastructure management. It provides these benefits without
compromising on any capability that a non-blade compute system provides.
Information Storage and Management (ISM) v4
Page 92
© Copyright 2019 Dell Inc.
Compute System Lesson
Some concerns with blade servers include the high cost of a blade system (blade
servers and chassis), and the proprietary architecture of most blade systems due to
which a blade server can typically be plugged only into a chassis from the same
vendor.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 93
Compute System Lesson
Physical Components of a Compute System
Component
Description
Processor
An IC that executes software programs by performing
arithmetical, logical, and input/output operations
Random-Access Volatile data storage that contains the programs for execution
Memory
and the data that are used by the processor
Read-Only
Memory
Semiconductor memory containing boot, power management,
and other device-specific firmware
Motherboard
A PCB that holds the processor, RAM, ROM, network and I/O
ports, and other integrated components, such as GPU and NIC
Chipset
A collection of microchips on a motherboard to manage specific
functions, such as processor access to RAM and to peripheral
ports
Secondary
Storage
A persistent storage device such as HDD or SSD
Notes
Key components are:

Processor: A processor, also known as a Central Processing Unit (CPU), is an
integrated circuit (IC). This processor executes the instructions of a software
program by performing fundamental arithmetical, logical, and input/output
operations. A common processor/instruction set architecture is the x86
architecture with 32-bit and 64-bit processing capabilities. Modern processors
have multiple cores (independent processing units), each capable of functioning
as an individual processor. Socket- A single package which can have one or
more processor cores with one or more logical processors in each core. A dualcore processor, for example, can provide almost double the performance of a
Information Storage and Management (ISM) v4
Page 94
© Copyright 2019 Dell Inc.
Compute System Lesson
single-core processor, by allowing two virtual CPUs to execute at the same
time.

Random-Access Memory (RAM): The RAM or main memory is an IC that
serves as a volatile data storage internal to a compute system. The RAM is
directly accessible by the processor, and holds the software programs for the
execution and the data that are used by the processor.

Read-Only Memory (ROM): A ROM is a type of non-volatile semiconductor
memory from which data can only be read but not written to. It contains the boot
firmware (that enables a compute system to start), power management
firmware, and other device-specific firmware.

Motherboard: A motherboard is a printed circuit board (PCB) to which all
compute system components connect. It has sockets to hold components such
as the microprocessor chip, RAM, and ROM. It also has network ports, I/O ports
to connect devices such as keyboard, mouse, and printers, and essential
circuitry to carry out computing operations. A motherboard may also have
integrated components, such as a graphics processing unit (GPU), a network
interface card (NIC), and adapters to connect to external storage devices.

Chipset: A chipset is a collection of microchips on a motherboard, and it is
designed to perform specific functions. The two key chipset types are
Northbridge and Southbridge. Northbridge manages processor access to the
RAM and the GPU, while Southbridge connects the processor to different
peripheral ports, such as USB ports.

Secondary storage: Secondary storage is a persistent storage device, such as
a hard disk drive or a solid-state drive. In this storage the OS and the
application software are installed. The processor cannot directly access
secondary storage. The desired applications and data are loaded from the
secondary storage on to the RAM to enable the processor to access them.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 95
Compute System Lesson
Logical Components of a Compute System
The key logical components of a compute system are:

Operating system

Virtual memory

Logical volume manager

File system
Information Storage and Management (ISM) v4
Page 96
© Copyright 2019 Dell Inc.
Compute System Lesson
Logical Components: Operating System
An operating system (OS) is software that acts as an intermediary between a user
of a compute system and the compute system hardware.
The OS manages hardware functions, applications execution, and provides a user
interface (UI) for users to operate and use the compute system.
User Applications
Operating System
User Interface
Command Line
GUI
System Calls (APIS)
Services
Program
Execution
Memory
Management
Resource
Management
I/O Operations
File System
Management
Networking
Security
Compute System Hardware
Notes
The image depicts a generic architecture of an OS. Some functions (or services) of
an OS include program execution, memory management, resources management
and allocation, and input/output management. An OS also provides networking and
basic security for the access and usage of all managed resources. It also performs
basic storage management tasks while managing other underlying components,
such as the device drivers, logical volume manager, and file system. An OS also
contains high-level Application Programming Interfaces (APIs) to enable programs
to request services.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 97
Compute System Lesson
Logical Components: Virtual Memory
The amount of physical memory (RAM) in a compute system determines both the
size and the number of applications that can run on the compute system.
Address Translation
Unavailable
Unavailable
Physical Memory
Virtual Memory
Storage
Drive
Notes
Memory virtualization presents physical memory to applications as a single logical
collection of contiguous memory locations called virtual memory. While executing
applications, the processor generates logical addresses (virtual addresses) that
map into the virtual memory. The memory management unit of the processor and
then maps the virtual address to the physical address. The OS utility, which is
known as the virtual memory manager (VMM), manages the virtual memory and
also the allocation of physical memory to virtual memory.
An extra memory virtualization feature of an OS enables the capacity of secondary
storage devices to be allocated to the virtual memory. This device creates a virtual
memory with an address space that is larger than the physical memory space
Information Storage and Management (ISM) v4
Page 98
© Copyright 2019 Dell Inc.
Compute System Lesson
present in the compute system. This virtual memory enables multiple applications
and processes, whose aggregate memory requirement is greater than the available
physical memory to run on a compute system without impacting each other.
The VMM manages the virtual-to-physical memory mapping. This VMM fetches
data from the secondary storage when a process references a virtual address that
points to data at the secondary storage. The space used by the VMM on the
secondary storage is known as a swap space. A swap space (also known as page
file or swap file) is a portion of the storage drive that is used as physical memory.
In a virtual memory implementation, the memory of a system is divided into
contiguous blocks of fixed-size pages. A process known as paging moves inactive
physical memory pages onto the swap file and brings them back to the physical
memory when required.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 99
Compute System Lesson
Logical Components: Logical Volume Manager (LVM)

Creates and controls compute
level logical storage:
Physical Volumes
 Provides a logical view of
physical storage
 Logical data blocks are
mapped to physical data
blocks

Physical volumes form a
volume group:
 LVM manages volume
groups as a single entity

Volume Group
Logical
Volume
Logical
Volume
Logical
Volume
Logical volumes are created
from a volume group
Notes
Logical Volume Manager (LVM) is software that runs on a compute system and
manages logical and physical storage. LVM is an intermediate layer between the
file system and the physical drives. It can partition a larger-capacity disk into virtual,
smaller-capacity volumes (partitioning) or aggregate several smaller disks to form a
larger virtual volume (concatenation). LVMs are mostly offered as part of the OS.
The evolution of LVMs enabled dynamic extension of file system capacity and
efficient storage management. The LVM provides optimized storage access and
simplifies storage resource management. It hides details about the physical disk
and the location of data on the disk. It enables administrators to change the storage
allocation even when the application is running.
The basic LVM components are physical volumes, logical volume groups, and
logical volumes. In LVM terminology, each physical disk that is connected to the
compute system is a physical volume (PV). A volume group is created by grouping
one or more PVs. A unique physical volume identifier (PVID) is assigned to each
PV when it is initialized for use by the LVM. Physical volumes can be added or
Information Storage and Management (ISM) v4
Page 100
© Copyright 2019 Dell Inc.
Compute System Lesson
removed from a volume group dynamically. Each PV is divided into equal-sized
data blocks called physical extents when the volume group is created.
Logical volumes (LV) are created within a given volume group. A LV can be
thought of as a disk partition, whereas the volume group itself can be thought of as
a disk. The size of a LV is based on a multiple of the number of physical extents.
The LV appears as a physical device to the OS. A LV is made up of noncontiguous
physical extents and may span over multiple physical volumes. A file system is
created on a logical volume.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 101
Compute System Lesson
Logical Components: LVM Example

Disk partitioning was introduced to improve the flexibility and utilization of disk
drives

In partitioning, a disk drive is divided into logical containers called logical
volumes.
Compute Systems
Logical
Volume(s)
Physical
Volume(s)
Partitioning
Concatenation
Notes
For example, a large physical drive can be partitioned into multiple LVs to maintain
data according to the file system and application requirements. The partitions are
created from groups of contiguous cylinders when the hard disk is initially set up on
the host. The host’s file system accesses the logical volumes without any
knowledge of partitioning and physical structure of the disk. Concatenation is the
process of grouping several physical drives and presenting them to the host as one
large logical volume.
Information Storage and Management (ISM) v4
Page 102
© Copyright 2019 Dell Inc.
Compute System Lesson
Logical Components: File System

File is a collection of related records stored as a single named unit in
contiguous logical address space.

A file system controls and manages the storage and retrieval of files.
 Enables users to perform various operations on files
 Groups and organizes files in a hierarchical structure.

File system may be broadly classified as:
 Disk-based file system
 Network-based file system
 Virtual file system
Notes
Files are of different types, such as text, executable, image, audio/video, binary,
library, and archive. Files have various attributes, such as name, unique identifier,
type, size, location, owner, and protection.
A file system is an OS component that controls and manages the storage and
retrieval of files in a compute system. A file system enables easy access to the files
residing on a storage drive, a partition, or a logical volume. It consists of logical
structures and software routines that control access to files. It enables users to
perform various operations on files, such as create, access (sequential/random),
write, search, edit, and delete.
A file system typically groups and organizes files in a tree-like hierarchical
structure. It enables users to group files within a logical collection called a directory,
which is containers for storing pointers to multiple files. A file system maintains a
pointer map to the directories, subdirectories (if any), and files that are part of the
file system. It also stores all the metadata (file attributes) associated with the files.
A file system block is the smallest unit allocated for storing data. Each file system
block is a contiguous area on the physical disk. The block size of a file system is
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 103
Compute System Lesson
fixed at the time of its creation. The file system size depends on the block size and
the total number of file system blocks
File systems may be broadly classified as follows:
Disk-based
A disk-based file system manages the files stored on storage devices such as
solid-state drives, disk drives, and optical drives. Examples of disk-based file
systems are Microsoft NT File System (NTFS), Apple Hierarchical File System
(HFS) Plus, Extended File System family for Linux, Oracle ZFS, and Universal Disk
Format (UDF).
Network-based
A network-based file system uses networking to enable file system access between
compute systems. Network-based file systems may use either the client/server
model, or may be distributed/clustered. In the client/server model, the file system
resides on a server, and is accessed by clients over the network. The client/server
model enables clients to mount the remote file systems from the server.
NFS for UNIX environment and CIFS for Windows environment (both covered in
Module, ‘File-based Storage System (NAS)’) are two standard client/server file
sharing protocols. Examples of network-based file systems are: Microsoft
Distributed File System (DFS), Hadoop Distributed File System (HDFS), VMware
Virtual Machine File System (VMFS), Red Hat GlusterFS, and Red Hat CephFS.
Virtual
A virtual file system is a memory-based file system. This process enables compute
systems to transparently access different types of file systems on local and network
storage devices. It provides an abstraction layer that enables applications to
access different types of file systems in a uniform way. It bridges the differences
between the file systems for different operating systems, without the application’s
knowledge of the type of file system they are accessing. The examples of virtual file
systems are Linux Virtual File System (VFS) and Oracle CacheFS.
Information Storage and Management (ISM) v4
Page 104
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
Compute and Desktop Virtualization Lesson
Introduction
This lesson covers compute virtualization, hypervisor, and virtual machine. This
lesson also covers desktop virtualization.
This lesson covers the following topics:

Explain compute virtualization, hypervisor, and virtual machine

Explain desktop virtualization
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 105
Compute and Desktop Virtualization Lesson
Compute and Desktop Virtualization
What is Compute Virtualization?
Definition: Compute Virtualization
The technique of abstracting the physical compute hardware from the
operating system and applications enabling multiple operating
systems to run concurrently on a single or clustered physical compute
system(s).
VM
VM
VM
APP
APP
APP
OS
OS
OS
Compute Virtualization (Hypervisor)
Pool of Physical Compute Capacity (x86 Hardware)
Notes
Compute virtualization is a technique of abstracting the physical hardware of a
compute system from the operating system (OS) and applications. The decoupling
of the physical hardware from the OS and applications enables multiple operating
systems to run concurrently on a single or clustered physical compute system(s).
Compute virtualization enables the creation of virtual compute systems called
virtual machines (VMs). Each VM runs an OS and applications, and is isolated from
the other VMs on the same compute system. Compute virtualization is achieved by
a hypervisor, which is virtualization software that is installed on a physical compute
system. The hypervisor provides virtual hardware resources, such as CPU,
Information Storage and Management (ISM) v4
Page 106
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
memory, storage, and network resources to all the VMs. Depending on the
hardware capabilities, many VMs can be created on a single physical compute
system.
A VM is a logical entity; but to the OS running on the VM, it appears as a physical
compute system, with its own processor, memory, network controller, and disks.
However, all VMs share the same underlying physical hardware of the compute
system. The hypervisor allocates the compute system’s hardware resources
dynamically to each VM. From a hypervisor’s perspective, each VM is a discrete
set of files.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 107
Compute and Desktop Virtualization Lesson
Need for Compute Virtualization
Before Virtualization
Drawbacks

IT silos and underutilized resources

Inflexible and expensive

Management inefficiencies

Risk of downtime
APP
After Virtualization
OS
X86 Hardware
Benefits:

Server consolidation and improved
resource utilization

Flexible infrastructure at lower costs

Increased management efficiency

Increased availability and improved business continuity
VM
VM
VM
APP
APP
APP
OS
OS
OS
Compute Virtualization (Hypervisor)
Pool of Physical Compute Capacity (x86 Hardware)
Notes
In an x86-based physical compute system, the software,
and hardware are tightly coupled and it can run only one OS at a time. A physical
compute system often faces resource conflicts when multiple applications running
on the compute have conflicting requirements. Moreover, many applications do not
take full advantage of the hardware capabilities available to them.
Information Storage and Management (ISM) v4
Page 108
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
Resources such as processors, memory, and storage frequently remain
underutilized. Many compute systems also requires complex network cabling and
considerable floor space and power requirements. Hardware configuration,
provisioning, and management become complex and require more time. A physical
compute is a single point of failure because its failure leads to application
unavailability.
Compute virtualization enables overcoming these challenges by allowing multiple
operating systems and applications to run on a single compute system. It converts
physical machines to virtual machines and consolidates the converted machines
onto a single compute system. Server consolidation improves resource utilization
and enables organizations to run their data center with a fewer machines. This
server consolidation, in turn reduces the hardware acquisition costs and
operational costs, and saves the data center space and energy requirements.
Compute virtualization increases the management efficiency and reduces the
maintenance time. The creation of VMs takes less time compared to a physical
compute setup. The organizations can provision compute resources faster, and
with greater ease to meet the growing resource requirements. Individual VMs can
be restarted, upgraded, or even failed, without affecting the other VMs on the same
physical compute. Moreover, VMs are portable and can be copied or moved from
one physical compute to another without causing application unavailability.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 109
Compute and Desktop Virtualization Lesson
What is a Hypervisor?
Definition: Hypervisor
Software that provides a virtualization layer for abstracting compute
system hardware, and enables the creation of multiple virtual
machines.

There are two key components
to a hypervisor
VM
VM
 Hypervisor Kernel
APP
APP
OS
OS
VMM
VMM
o Provides functionality
similar to an OS kernel
o Presents resource
requests to physical
hardware
 Virtual machine manager
(VMM)
Hypervisor Kernel
Physical Compute System
o Each VM is assigned a
VMM

There are also two types of hypervisor
 Bare-metal
 Hosted
Notes
Hypervisor is a compute virtualization software that is installed on a compute
system. It provides a virtualization layer that abstracts the processor, memory,
network, and storage of the compute system and enables the creation of multiple
virtual machines. Each VM runs its own OS, which essentially enables multiple
Information Storage and Management (ISM) v4
Page 110
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
operating systems to run concurrently on the same physical compute system. The
hypervisor provides standardized hardware resources to all the VMs.
A hypervisor has two key components: kernel and virtual machine manager (VMM).
A hypervisor kernel provides the same functionality as the kernel of any OS,
including process management, file system management, and memory
management. It is designed and optimized to run multiple VMs concurrently. It
receives requests for resources through the VMM, and presents the requests to the
physical hardware. Each virtual machine is assigned a VMM that gets a share of
the processor, memory, I/O devices, and storage from the physical compute
system to successfully run the VM.
Hypervisors are categorized into two types: bare-metal (Type I) and hosted (Type
II). A bare-metal hypervisor is directly installed on the physical compute hardware
in the same way as an OS. It has direct access to the hardware resources of the
compute system and is therefore more efficient than a hosted hypervisor. A baremetal hypervisor is designed for enterprise data centers and third platform
infrastructure. It also supports the advanced capabilities such as resource
management, high availability, and security. The image represents a bare-metal
hypervisor. A hosted hypervisor is installed as an application on an operating
system. The hosted hypervisor does not have direct access to the hardware, and
all requests pass through the OS running on the physical compute system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 111
Compute and Desktop Virtualization Lesson
What is a Virtual Machine?
Definition: Virtual Machine (VM)
A logical compute system with virtual hardware on which a supported
guest OS and its applications run.
Important points about a VM:

Created by a hypervisor installed on a physical compute system

Comprises virtual hardware, such as virtual processor, virtual storage, and
virtual network resources

Appears as a physical compute system to the guest OS

Hypervisor maps the virtual hardware to the physical hardware

VMs on a compute system are isolated from each other
Notes
A virtual machine (VM) is a logical compute system with virtual hardware on which
a supported guest OS and its applications run. A VM is created by a hosted or a
bare-metal hypervisor installed on a physical compute system. An OS, called a
“guest OS”, is installed on the VM in the same way it is installed on a physical
compute system. From the perspective of the guest OS, the VM appears as a
physical compute system.
A VM has a self-contained operating environment, comprising OS, applications,
and virtual hardware, such as a virtual processor, virtual memory, virtual storage,
and virtual network resources. As discussed previously, a dedicated virtual
machine manager (VMM) is responsible for the execution of a VM. Each VM has its
own configuration for hardware, software, network, and security. The hypervisor
translates the VM’s resource requests and maps the virtual hardware of the VM to
the hardware of the physical compute system. For example, a VM’s I/O requests
Information Storage and Management (ISM) v4
Page 112
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
that to a virtual disk drive are translated by the hypervisor and mapped to a file on
the physical compute system’s disk drive
Compute virtualization software enables creating and managing several VMs. Each
VM has a different OS of its own—on a physical compute system or on a compute
cluster. VMs are created on a compute system, and provisioned to different users
to deploy their applications. The VM hardware and software are configured to meet
the application’s requirements. The different VMs are isolated from each other, so
that the applications and the services running on one VM do not interfere with
those running on other VMs. The isolation also provides fault tolerance so that if
one VM crashes, the other VMs remain unaffected.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 113
Compute and Desktop Virtualization Lesson
VM Hardware

When a VM is created, it is presented with virtual hardware components that
appear as physical hardware components to the guest OS

Within a given vendor’s environment, each VM has standardized hardware
components that make them portable across physical compute systems

The image shows the typical hardware components of a VM
Floppy/Optical Drives and
Controllers
HBA
RAM
Graphics
Card
Storage
Device
VM
Hardware
Mouse
SCSI/IDE
Controllers
Keyboard
USB
Controller
Processor
NIC
Notes
Based on the requirements, the virtual components can be added or removed from
a VM. However, not all components are available for addition and configuration.
Some hardware devices are part of the virtual motherboard and cannot be modified
Information Storage and Management (ISM) v4
Page 114
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
or removed. For example, the video card and the PCI controllers are available by
default and cannot be removed.
A VM can be configured with one or more virtual processors. Each VM is assigned
a virtual motherboard with the standardized devices essential for a compute system
to function. Virtual RAM is the amount of physical memory allocated to a VM, and it
can be configured based on the requirements. The virtual disk is a large physical
file, or a set of files that stores the VM’s OS, program files, application data, and
other data associated with the VM. A virtual network adapter functions like a
physical network adapter. It provides connectivity between VMs running on the
same or different compute systems, and between a VM and physical compute
systems.
Virtual optical drives and floppy drives can be configured to connect to either
physical devices or to image files, such as ISO on the storage. SCSI/IDE virtual
controllers provide a way for the VMs to connect to the storage devices. The virtual
USB controller is used to connect to a physical USB controller and to access the
connected USB devices. Serial and parallel ports provide an interface for
connecting peripherals to the VM.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 115
Compute and Desktop Virtualization Lesson
VM Files
From a hypervisor’s perspective, a VM is a discrete set of files on a storage device.
These files are:
Configuration file
Stores information, such as VM name, BIOS information,
guest OS type, memory size
Virtual disk file
Stores the contents of the VM's disk drive
Memory state file
Stores the memory contents of a VM in a suspended state
Snapshot file
Stores the VM settings and virtual disk of a VM
Log file
Keeps a log of the VM’s activity and is used in troubleshooting
Notes
From a hypervisor’s perspective, a VM is a discrete set of files on a storage device.
Some of the key files that make up a VM are the configuration file, the virtual disk
file, the memory file, and the logfile. The configuration file stores the VM’s
configuration information, including VM name, location, BIOS information, guest OS
type, virtual disk parameters, number of processors, memory size, number of
adapters and associated MAC addresses, SCSI controller type, and disk drive type.
The virtual disk file stores the contents of a VM’s disk drive. A VM can have
multiple virtual disk files, each of which appears as a separate disk drive to the VM.
The memory state file stores the memory contents of a VM and is used to resume a
VM that is in a suspended state. The snapshot file stores the running state of the
VM including its settings and the virtual disk, and may optionally include the
memory state of the VM. It is typically used to revert the VM to a previous state.
Log files are used to keep a record about the VM’s activity and are often used for
troubleshooting purposes.
Information Storage and Management (ISM) v4
Page 116
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
For managing VM files, a hypervisor may use a native clustered file system, or the
Network File System (NFS). A hypervisor’s native clustered file system is optimized
to store VM files. It may be deployed on Fibre Channel and iSCSI storage, apart
from the local storage. The virtual disks are stored as files on the native clustered
file system. Network File System enables storing of VM files on remote file servers
(NAS device) accessed over an IP network. The NFS client built into the hypervisor
uses the NFS protocol to communicate with the NAS device.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 117
Compute and Desktop Virtualization Lesson
What is Desktop Virtualization?
Definition: Desktop Virtualization
Technology that decouples the OS, applications, and user state from
a physical compute system to create a virtual desktop environment
that can be accessed from any client device.

Desktops are hosted and managed centrally

Desktop virtualization benefits include
 Simplified desktop infrastructure management
 Improved data protection and compliance
 Flexibility of access
Notes
With the traditional desktop machine, the OS, applications, and user profiles are all
tied to a specific piece of hardware. With legacy desktops, business productivity is
impacted greatly when a client device is broken or lost. Managing a vast desktop
environment is also a challenging task.
Desktop virtualization decouples the OS, applications, and user state (profiles,
data, and settings) from a physical compute system. These components,
collectively called a virtual desktop, are hosted on a remote compute system. It can
be accessed by a user from any client device, such as laptops, desktops, thin
clients, or mobile devices. A user accesses the virtual desktop environment over a
network on a client through a web browser or a client application.
The OS and applications of the virtual desktop execute on the remote compute
system, while a view of the virtual desktop’s user interface (UI) is presented to the
end-point device. Desktop virtualization uses a remote display protocol to transmit
the virtual desktop’s UI to the end-point devices. The remote display protocol also
Information Storage and Management (ISM) v4
Page 118
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
sends back keystrokes and graphical input information from the end-point device,
enabling the user to interact with the virtual desktop.
Some key benefits of desktop virtualization are:

Simplified desktop infrastructure management: Desktop virtualization
simplifies desktop infrastructure management, and creates an opportunity to
reduce the maintenance costs. New virtual desktops can be configured and
deployed faster than physical machines. The patches, updates, and upgrades
can be centrally applied to the OS and applications. This process simplifies or
eliminates many redundant, manual, and time-consuming tasks.

Improved data protection and compliance: Applications and data are located
centrally, which ensures that business-critical data is not at risk if there is loss or
theft of the device. Virtual desktops are also easier to back up compared to
deploying backup solutions on end-point devices.

Flexibility of access: Desktop virtualization enables users to access their
desktops and applications without being bound to a specific end-point device.
The virtual desktops can be accessed remotely from different end-point devices.
These benefits create a flexible work scenario and enables user productivity
from remote locations. Desktop virtualization also enables Bring Your Own
Device (BYOD), which creates an opportunity to reduce acquisition and
operational costs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 119
Compute and Desktop Virtualization Lesson
Use Cases for Compute and Desktop Virtualization
Compute and desktop virtualization provide several benefits to organizations and
facilitate the transformation to the modern data center. Two use cases are
described below.
Use Case
Description
Cloud Application
Streaming

Streaming applications from the cloud to diverse
client devices

Applications flexibly scale to meet growth in
processing and storage needs

Applications can be delivered to devices on which
they may run natively

Cloud service in which a VDI is hosted by a cloud
service provider

Provider manages VDI and OS updates

Facilitates CAPEX and OPEX savings
Desktop as a Service
(DaaS)
Cloud application streaming: Cloud application streaming employs application
virtualization to stream applications from the cloud to client devices. Streaming
applications from the cloud enable organizations to reach more users on multiple
devices, without modifying the application code. The application is deployed on a
cloud infrastructure, and the output is streamed to client devices, such as desktops,
tablets, and mobile phones. Because the application runs in the cloud, it can
flexibly scale to meet the massive growth in processing and storage needs,
regardless of the client devices the end users are using. The cloud service can
stream either all or portions of the application from the cloud. Cloud application
streaming enables an application to be delivered to client devices on which it may
not be possible to run the application natively.
Information Storage and Management (ISM) v4
Page 120
© Copyright 2019 Dell Inc.
Compute and Desktop Virtualization Lesson
Desktop as a Service: Desktop as a Service (DaaS) is a cloud service in which a
virtual desktop infrastructure (VDI) is hosted by a cloud service provider. The
provider offers a complete, business-ready VDI solution, delivered as a cloud
service with either subscription-based, or pay-as-you-go billing. The service
provider (internal IT or public) manages the deployment of the virtual desktops,
data storage, backup, security, and OS updates/upgrades. The virtual desktops are
securely hosted in the cloud and managed by the provider. DaaS has a multitenant
architecture, wherein virtual desktops of multiple users share the same underlying
infrastructure. However, individual virtual desktops are isolated from each other
and protected against unauthorized access and crashes on other virtual desktops.
The virtual desktops can be easily provisioned by consumers, and they are
delivered over the Internet to any client device. DaaS provides organizations with a
simple, flexible, and efficient approach to IT. It enables to lower CAPEX and OPEX
for acquiring and managing end-user computing infrastructure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 121
Storage and Network Lesson
Storage and Network Lesson
Introduction
This lesson covers evolution of storage architecture and the types of storage
devices. This lesson also covers compute-to-compute and compute-to-storage
connectivity. Further, this lesson covers different storage connectivity protocols.
This lesson covers the following topics:

Explain evolution of storage architecture

List types of storage devices

Explain compute-to-compute and compute-to-storage connectivity

Explain storage connectivity protocols
Information Storage and Management (ISM) v4
Page 122
© Copyright 2019 Dell Inc.
Storage and Network Lesson
Storage and Network
Evolution of Storage Architecture: Server-Centric (Internal DAS)

In a traditional environment, business units/departments in an organization have
their own servers running the business applications of the respective business
unit/department:
 Storage devices are connected directly to the servers and are typically
internal to the server
 These storage devices cannot be shared with any other server
 This is called server-centric storage architecture (Internal DAS)

In this architecture:
 Each server has a limited number of storage devices
 The storage device exists only in relation to the server to which it is
connected

The figure depicts an example of server-centric architecture; in the image:
 The servers of different departments in an organization have directly
connected storage
 Clients connect to the servers over a local area network (LAN) or a wide
area network (WAN)
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 123
Storage and Network Lesson
Sales Server
Storage Device
Clients
LAN/WAN
Finance Server
Storage Device
R&D Server
Storage Device
Notes
Traditional server-centric architecture (Internal DAS) has several limitations, and is
inadequate to satisfy the growing demand for storage capacity in modern
applications environments. The number of storage devices that can be connected
to one server is limited, and it is not possible to scale the storage capacity.
Moreover, a server cannot directly access the unused storage space available on
other servers.
A server failure or any administrative tasks, such as maintenance of the server or
increasing its storage capacity, also results in unavailability of information.
Furthermore, the proliferation of departmental servers in an organization results in
silos of information. These devices are difficult to manage and lead to an increase
in capital expenditure (CAPEX) and operating expenditure (OPEX).
Information Storage and Management (ISM) v4
Page 124
© Copyright 2019 Dell Inc.
Storage and Network Lesson
Evolution of Storage Architecture: Information-Centric (SAN)

To overcome the challenges of the server-centric architecture, storage evolved
to the information-centric architecture

In information-centric architecture (SAN), storage devices exist independently of
servers, and are managed centrally and shared between multiple compute
systems

The figure depicts an example of information-centric architecture; in the image:
 The servers of different departments in an organization are connected to the
shared storage over a SAN
 The clients connect to the servers over a LAN or a WAN
 When a new server is deployed in the environment, storage is assigned to
the server from the same shared pool of storage devices
 The storage capacity can be increased dynamically and without impacting
information availability by adding storage devices to the pool

This architecture improves the overall storage capacity utilization, while making
management of information and storage more flexible and cost-effective
Sales Server
Clients
Storage Area
Network
LAN/WAN
Finance Server
Storage Devices
R&D Server
Notes
Storage devices assembled within storage systems form a storage pool, and
several compute systems access the same storage pool over a specialized, high-
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 125
Storage and Network Lesson
speed storage area network (SAN). A SAN is used for information exchange
between compute systems and storage systems, and for connecting storage
systems. It enables compute systems to share storage resources, improve the
utilization of storage systems, and facilitate centralized storage management.
SANs are classified based on protocols they support. Common SAN deployment
types are Fibre Channel SAN (FC SAN), Internet Protocol SAN (IP SAN), and Fibre
Channel over Ethernet SAN (FCoE SAN). These topics are covered later in the
course.
Information Storage and Management (ISM) v4
Page 126
© Copyright 2019 Dell Inc.
Storage and Network Lesson
Types of Storage Devices
Storage
Type
Description
Magnetic
disk drive

Stores data on a circular disk with a ferromagnetic coating

Provides random read/write access

Most popular storage device with large storage capacity
Solid-state
(flash) drive

Stores data on a semiconductor-based memory

Very low latency per I/O, low power requirements, and very high
throughput
Magnetic
tape drive

Stores data on a thin plastic film with a magnetic coating

Provides only sequential data access

Low-cost solution for long term data storage

Stores data on a polycarbonate disc with a reflective coating

Write Once and Read Many capability: CD, DVD, BD

Low-cost solution for long-term data storage
Optical disc
drive
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 127
Storage and Network Lesson
Overview of Storage Virtualization

Abstracts physical storage resources to create virtual storage resources:
 Virtual volumes
 Virtual disk files
 Virtual storage systems

Storage virtualization software can be
 Built into the operating environment of a storage system
 Installed on an independent compute system
 Built into a hypervisor
Information Storage and Management (ISM) v4
Page 128
© Copyright 2019 Dell Inc.
Storage and Network Lesson
Introduction to Connectivity

Communication paths between IT infrastructure components for information
exchange and resource sharing

Types of connectivity
 Compute-to-compute connectivity
 Compute-to-storage connectivity
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 129
Storage and Network Lesson
Compute-to-Compute Connectivity

Compute-to-compute connectivity typically uses protocols based on the Internet
Protocol (IP)
 Each physical compute system is connected to a network through one or
more host interface devices, called a network interface controller (NIC)
 Physical switches and routers are the commonly used interconnecting
devices
 A switch enables different compute systems in the network to communicate
with each other

A router is an OSI Layer-3 device that enables different networks to
communicate with each other
 Commonly used network cables are copper cables and optical fiber cables

The figure shows a network (LAN or WAN) that provides interconnections
among the physical compute systems:
 It is necessary to ensure that appropriate switches and routers, with
adequate bandwidth and ports, are available to provide the required network
performance
VM
VM
APP
AP
P
OS
OS
Hypervisor
Compute
Systems
Client
Ethernet Switch
IP Router
Ethernet Switch
VM
VM
AP
P
AP
P
OS
OS
Hypervisor
Information Storage and Management (ISM) v4
Page 130
© Copyright 2019 Dell Inc.
Storage and Network Lesson
Compute-to-Storage Connectivity

Enabled through physical components and interface protocols

Physical connectivity components
 Host bus adapter, port, and cable

Storage may be connected directly or over a SAN
Clients
Ethernet Switch
LAN
Servers
iSCSI Target
FC Switch
Storage System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 131
Storage and Network Lesson
Notes
Storage may be connected directly to a compute system or over a SAN.
Connectivity and communication between compute and storage are enabled
through physical components and interface protocols. The physical components
that connect compute to storage are host interface device, port, and cable.
Host bus adapter: A host bus adapter (HBA) is a host interface device that
connects a compute system to storage or to a SAN. It is an application-specific
integrated circuit (ASIC) board. It performs I/O interface functions between a
compute system and storage, relieving the processor from more I/O processing
workload. A compute system typically contains multiple HBAs.
Port: A port is a specialized outlet that enables connectivity between the compute
system and storage. An HBA may contain one or more ports to connect the
compute system to the storage. Cables connect compute systems to internal or
external devices using copper or fiber optic media.
Information Storage and Management (ISM) v4
Page 132
© Copyright 2019 Dell Inc.
Storage and Network Lesson
What is a Protocol?
Definition: Protocols
Define formats for communication between devices. Protocols are
implemented using interface devices (or controllers) at both the
source and the destination devices.
Protocol
Description
Fibre Channel (FC)

Widely used protocol for high-speed computeto-storage communication

Provides a serial data transmission that
operates over copper wire and/or optical fiber

Existing IP-based network leveraged for
storage communication

Examples: iSCSI and FCIP protocols
Internet Protocol (IP)
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 133
Storage and Network Lesson
Overview of Network Virtualization
Abstracts physical network resources to create virtual network resources:

Virtual switch

Virtual LAN

Virtual SAN
Network virtualization software can be:

Built into the operating environment of a network device

Installed on an independent compute system

Built into a hypervisor
Information Storage and Management (ISM) v4
Page 134
© Copyright 2019 Dell Inc.
Applications Lesson
Applications Lesson
Introduction
This lesson covers traditional and modern application. Further, this lesson covers
microservices and application virtualization.
This lesson covers the following topics:

Explain traditional and modern applications

Explain microservices

Describe application virtualization
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 135
Applications Lesson
Applications
Application Overview
Definition: Application

Definition: Application
– A software program or set of
programs that is designed to
perform a group of
coordinated tasks.

Examples
– Customer relationship
management (CRM)
Applications
– Enterprise Resource
Planning (ERP)
– Email such as Microsoft
Outlook
Notes
For anyone who uses computers or smartphones, applications are used every day.
From reading your email to Facebook and Twitter, when you post pictures or write
your tweet, you are using an application.
For the business, applications unlock value from the digital world. Using a great
application reshapes user experiences and creates touch points in how to get the
information you want. Applications are crucial in how businesses provide value to
their customers, which drives fundamental business objectives. Applications
Information Storage and Management (ISM) v4
Page 136
© Copyright 2019 Dell Inc.
Applications Lesson
manage the information and provide it in a form that is useful to the business to
meet specific requirements.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 137
Applications Lesson
Modern Applications
Modern applications consist of a set of business-related functional parts, called
microservices, that are assembled with specific rules and best practices.
Modern Applications

It deliver the services
in hours and not
weeks or months that
are common in the
new world of a digital
business

Long-term technology
commitments are
reduced

Things are loosely
coupled making updates much easier and seamless from the end user
perspective

Examples: Facebook, Uber, and Netflix
Microservices

Microservices run in their own process and
communicate to other services through
REST APIs

It is a distinctive method of developing
software systems that has grown in
popularity in recent years

In this architecture, the application is
decomposed into small, loosely coupled,
and independently operating services
Information Storage and Management (ISM) v4
Page 138
© Copyright 2019 Dell Inc.
Applications Lesson
Traditional vs. Modern Applications
Traditional Application
Characteristics
Modern Application Characteristics
Monolithic
Distributed
Common programming language
Multiple programming languages
Resiliency and scale are infrastructure
managed
Resiliency and scale are application
managed
Infrastructure is application-specific
Infrastructure is application-agnostic
PC-based devices
Large variety of devices (BYOD)
Separate Build/Test/Run
DevOps, Continuous development and
deployment
Examples: CRM, ERP, and Email –
Microsoft Outlook
Examples: Facebook, Uber, and Netflix
Notes
Traditional applications are monolithic, it means, the modules are interdependent.
Changing one affects the others. Modern applications are designed to run
independently. These independent and distributed runtime modules that make up
an application are termed microservices.
Generally traditional applications are built using a single programming language
and framework. The modern application modules are decomposed, multiple
programming languages can be used to develop these applications.
The source code for traditional application is commonly commercial off-the-shelf, or
custom developed in-house, such as Oracle Financials. The modern applications
often use open-source or support a Freemium model, where the code is available
as open-source but support and enhancements can be purchased.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 139
Applications Lesson
In traditional application environment, the infrastructure manages the resiliency
from hardware failure and scalability of the application. The modern application
handles component failure and scalability itself, by using distributed system
architectures driving high availability.
Information Storage and Management (ISM) v4
Page 140
© Copyright 2019 Dell Inc.
Applications Lesson
What is Application Virtualization?
Definition: Application Virtualization
The technique of decoupling an application from the underlying
computing platform (operating system and hardware) to enable the
application to be used on a compute system without installation.
An application is either delivered from a remote compute system, or encapsulated
in a virtualized container.
Application Virtualization benefits are

Simplified application deployment and management

Eliminate OS modifications

Resolve application conflicts and compatibility issues

Flexibility of application access
Notes
Some key benefits of application virtualization are described below.

Simplified application management: Application virtualization provides a
solution to meet an organization’s need for simplified and improved application
deployment, delivery, and manageability.

Eliminate OS modifications: Since application virtualization decouples an
application from the OS, it leaves the underlying OS unaltered. This process
provides additional security, and protects the OS from potential corruptions and
problems that may arise due to changes to the file system and registry.

Resolve application conflicts and compatibility issues: Application
virtualization enables the use of conflicting applications on the same end-point
device. It also enables the use of applications that otherwise do not execute on
an end-point device due to incompatibility with the underlying computing
platform.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 141
Applications Lesson

Simplified OS image management: Application virtualization simplifies OS
image management. Since application delivery is separated from the OS, there
is no need to include "standard" applications in end-point images. As a result,
managing images is simpler, especially in the context of OS patches and
upgrades.

Flexibility of access: Application virtualization enables an organization’s
workforce and customers to access applications hosted on a remote compute
system from any location, and through diverse end-point devices types.
Information Storage and Management (ISM) v4
Page 142
© Copyright 2019 Dell Inc.
Applications Lesson
Application Virtualization Techniques
Listed are the three techniques for application virtualization:

Application encapsulation
 Application is converted into a standalone, self-contained executable
package
 Application packages may run directly from local drive, USB, or optical disc

Application presentation
 Application is hosted and executes remotely, and the application’s UI data is
transmitted to client
 Locally-installed agent on the client manages the exchange of UI information
with user’s remote application session

Application streaming
 Application-specific data is transmitted in portions to clients for local
execution
 Requires locally-installed agent, client software, or web browser plugin
Application Encapsulation
In application encapsulation, an application is aggregated within a virtualized
container, along with the assets, such as files, virtual registry, and class libraries
that it requires for execution. This process, known as packaging or sequencing,
converts an application into a standalone, self-contained executable package that
can directly run on a compute system. The assets required for execution are
included within the virtual container. Therefore, the application does not have any
dependency on the underlying OS, and does not require a traditional installation on
the compute system.
The application’s virtual container isolates it from the underlying OS and other
applications, thereby minimizing application conflicts. During application execution,
all function calls made by the application to the OS for assets get redirected to the
assets within the virtual container. The application is thus restricted from writing to
the OS file system or registry, or modifying the OS in any other way.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 143
Applications Lesson
Application Presentation
In application presentation, an application’s user interface (UI) is separated from its
execution. The application executes on a remote compute system, while its UI is
presented to an end-point client device over a network. When a user accesses the
application, the screen pixel information and the optional sound for the application
are transmitted to the client. A software agent installed on the client receives this
information and updates the client’s display. The agent also transmits the
keystrokes and graphical input information back from the client, allowing the user to
control the application.
This process makes it appear as if the application is running on the client when, in
fact, it is running on the remote compute system. Application presentation enables
the delivery of an application on devices that have less computing power than what
is normally required to execute the application. In application presentation,
application sessions are created in the remote compute system and a user
connects to an individual session from a client by means of the software agent.
Individual sessions are isolated from each other, which secures the data of each
user and also protects the application crashes.
Application Streaming
In application streaming, an application is deployed on a remote compute system,
and is downloaded in portions to an end-point client device for local execution. A
user typically launches the application from a shortcut, which causes the client to
connect to the remote compute system to start the streaming process. Initially, only
a limited portion of the application is downloaded into memory. This portion is
sufficient to start the execution of the application on the client.
Since a limited portion of the application is delivered to the client before the
application starts, the user experiences rapid application launch. The streaming
approach also reduces network traffic. As the user accesses different application
functions, more of the application is downloaded to the client. The additional
portions of the application may also be downloaded in the background without user
intervention. Application streaming requires an agent or client software on clients.
Alternatively, the application may be streamed to a web browser by using a plug-in
installed on the client. In some cases, application streaming enables offline access
to the application by caching them locally on the client.
Information Storage and Management (ISM) v4
Page 144
© Copyright 2019 Dell Inc.
Applications Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 145
Software-Defined Data Center (SDDC) Lesson
Software-Defined Data Center (SDDC) Lesson
Introduction
This lesson covers software-defined data center and its architecture. This lesson
also covers software-defined controller and the benefits of software-defined
architecture.
This lesson covers the following topics:

Explain software-defined data center architecture

Explain software-defined controller

List benefits of software-defined data center architecture
Information Storage and Management (ISM) v4
Page 146
© Copyright 2019 Dell Inc.
Software-Defined Data Center (SDDC) Lesson
Software-Defined Data Center (SDDC)
What is a Software-Defined Data Center?
Definition: Software-Defined Data Center (SDDC)
An architectural approach to IT infrastructure that extends
virtualization concepts such as abstraction, pooling, and automation
to all of the data center’s resources and services to achieve IT as a
service.

Compute, storage, network, security, and availability services are pooled and
delivered as a service
 SDDC services are managed by intelligent, policy-driven software

Regarded as the foundational infrastructure for the modern data centere
Notes
In an SDDC, compute, storage, networking, security, and availability services are
pooled, aggregated, and delivered as a service. SDDC services are managed by
intelligent, policy-driven software.SDDC is a vision that can be interpreted in many
ways and can be implemented by numerous concrete architectures.
Typically, an SDDC is viewed as a conglomeration of virtual infrastructure
components, among which are software-defined compute (compute virtualization),
software-defined network (SDN), and software-defined storage (SDS).
SDDC is viewed as an important step in the progress towards a complete
virtualized data center (VDC), and is regarded as the necessary foundational
infrastructure for the modern data center.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 147
Software-Defined Data Center (SDDC) Lesson
SDDC Architecture

The software-defined approach separates the control or management functions
from the underlying components and provides it to external software

The external software takes over the control operations and enables the
management of multi-vendor infrastructure components centrally
Applications
APIs
Software-Defined Compute (Controller)
Software-Defined Storage (Controller)
Software-Defined Network (Controller)
APIs
Compute
Storage
Network
Notes
Principally, a physical infrastructure component (compute, network, and storage)
has a control path and a data path. The control path sets and manages the policies
for the resources, and the data path performs the transmission of data. The
software-defined approach decouples the control path from the data path. By
abstracting the control path, resource management function operates at the control
layer. This layer gives the ability to partition the resource pools, and manage them
uniquely by policy.
This decoupling of the control path and data path enables the centralization of data
provisioning and management tasks through software that is external to the
infrastructure components. The software runs on a centralized compute system or
a stand-alone device, called the software-defined controller. The figure illustrates
Information Storage and Management (ISM) v4
Page 148
© Copyright 2019 Dell Inc.
Software-Defined Data Center (SDDC) Lesson
the software-defined architecture, where the management function is abstracted
from the underlying infrastructure components using controller.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 149
Software-Defined Data Center (SDDC) Lesson
Software-Defined Controller

Discovers underlying resources and provides an aggregated view of resources
 Abstracts the underlying hardware resources and pools them

Enables the rapid provisioning of resources based on predefined policies

Enables to apply policies uniformly across the infrastructure components, all
from a software interface

Provides interfaces that enable applications external to the controller to request
resources and access them as services
Notes
A software-defined controller is software with built-in intelligence that automates
provisioning and configuration based on the defined policies. It enables
organizations to dynamically, uniformly, and easily modify and manage their
infrastructure.
The controller discovers the available underlying resources and provides an
aggregated view of resources. It abstracts the underlying hardware resources
(compute, storage, and network) and pools them. This enables the rapid
provisioning of resources from the pool based on predefined policies that align to
the service level agreements for different consumers.
The controller provides a single control point to the entire infrastructure enabling
policy-based infrastructure management. The controller enables an administrator to
use a software interface to manage the resources, node connectivity, and traffic
flow; control behavior of underlying components; apply policies uniformly across
the infrastructure components; and enforce security.
The controller also provides interfaces that enable applications, external to the
controller, to request resources and access these resources as services.
Information Storage and Management (ISM) v4
Page 150
© Copyright 2019 Dell Inc.
Software-Defined Data Center (SDDC) Lesson
Benefits of Software-Defined Architecture
By extending virtualization throughout the data center, SDDC provides several
benefits to the organizations. Some key benefits are described here:
Benefit
Description
Agility

On-demand self-service

Faster resource provisioning
Cost efficiency

Use of the existing infrastructure and commodity hardware
lowers CAPEX
Improved control

Policy-based governance

Automated Business Continuity (BC) / Disaster Recovery
(DR)

Support for operational analytics
Centralized
management

Unified management platform for centralized monitoring
and administration
Flexibility

Use of commodity and advanced hardware technologies

Hybrid cloud support
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 151
Modern Data Center Infrastructure Lesson
Modern Data Center Infrastructure Lesson
Introduction
This lesson covers the building blocks of a data center infrastructure. It covers the
components and functions of the five layers of a data center. It also covers the
three cross-layer functions in a data center.
This lesson covers the following topics:

List layers of a data center infrastructure

Explain components and functions of each layer

Explain cross-layer functions in a data center
Information Storage and Management (ISM) v4
Page 152
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Modern Data Center Infrastructure
Modern Data Center Infrastructure
The image is a block diagram depicting the core IT infrastructure building blocks
that make up a data center.
APPLICATIONS
Internal
Applications
Business
Applications
Modern
Applications
Cloud Extensibility
Cloud
DATA CENTER INFRASTRUCTURE
MANAGEMENT
SERVICES
Self-Service
Portal
ORCHESTRATION
BUSINESS
CONTINUITY
Service Catalog
SECURITY
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and
Archive
Security
Mechanisms
Network
Replication
Governance, Risk, and
Compliance
VIRTUAL INFRASTRUCTURE
Virtual Compute
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage Operation
Management
Compute
Storage
Notes
The IT infrastructure is arranged in five logical layers and three cross-layer
functions. The five layers are physical infrastructure, virtual infrastructure, softwaredefined infrastructure, orchestration, and services. Each of these layers has various
types of hardware and/or software components as shown in the figure. The three
cross-layer functions are business continuity, security, and management. Business
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 153
Modern Data Center Infrastructure Lesson
continuity and security functions include mechanisms and processes that are
required to provide reliable and secure access to applications, information, and
services. The management function includes various processes that enable the
efficient administration of the data center and the services for meeting business
requirements. Applications that are deployed in the data center may be a
combination of internal applications, business applications, and modern
applications that are either custom-built or off-the-shelf. The fulfillment of the five
essential cloud characteristics ensures the infrastructure can be transformed into a
cloud infrastructure that could be either private or public. Further, by integrating
cloud extensibility, the infrastructure can be connected to an external cloud to
leverage the hybrid cloud model.
Information Storage and Management (ISM) v4
Page 154
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Physical Infrastructure
Foundation layer of the data
center infrastructure
APPLICATIONS
Internal Applications
Business
Applications
Modern
Applications
Cloud
Extensibilit
Cl
DATA CENTER INFRASTRUCTURE
Physical components are:
compute systems, storage, and
network devices; they require
operating systems, system
software, and protocols for their
functions
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined
Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
Network
Replication
Governance, Risk,
and Compliance
VIRTUAL INFRASTRUCTURE
Virtual Compute
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Compute
Storage
Executes the requests generated
by the virtual and software-defined
layers
Notes
The physical infrastructure forms the foundation layer of a data center. It includes
equipment such as compute systems, storage systems, and networking devices.
This equipment along with the operating systems, system software, protocols, and
tools that enable the physical equipment to perform their functions. A key function
of physical infrastructure is to execute the requests generated by the virtual and
software-defined infrastructure. Additional functions are: storing data on the storage
devices, performing compute-to-compute communication, executing programs on
compute systems, and creating backup copies of data.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 155
Modern Data Center Infrastructure Lesson
Virtual Infrastructure
Virtualization abstracts physical
resources and creates virtual
resources.
APPLICATIONS
Business
Applications
Internal Applications
Modern
Applications
Cloud
Extensibilit
Clo
DATA CENTER INFRASTRUCTURE
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
Virtual components:
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE

Software-Defined
Compute
Virtual compute, virtual
storage, and virtual network.
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
VIRTUAL INFRASTRUCTURE
Virtual Compute
Security Mechanisms
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)

Created from physical resource
pools using virtualization
software
Storage
Operation
Compute
Storage
Network
Replication
Governance, Risk,
and Compliance
Benefits of virtualization:

Resource consolidation and multitenant environment

Improved resource utilization and increased ROI

Flexible resource provisioning and rapid elasticity
Notes
Virtualization is the process of abstracting physical resources, such as compute,
storage, and network, and creating virtual resources from them. Virtualization is
achieved by using virtualization software that is deployed on compute systems,
storage systems, and network devices.
Virtualization software aggregates physical resources into resource pools from
which it creates virtual resources. A resource pool is an aggregation of computing
resources, such as processing power, memory, storage, and network bandwidth.
For example, storage virtualization software pools the capacity of multiple storage
devices to create a single large storage capacity. Similarly, compute virtualization
software pools the processing power and memory capacity of a physical compute
system. This physical computes create an aggregation of the power of all
processors (in megahertz) and all memory (in megabytes). Examples of virtual
resources include virtual compute (virtual machines), virtual storage (LUNs), and
virtual networks.
Information Storage and Management (ISM) v4
Page 156
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Virtualization enables a single hardware resource to support multiple concurrent
instances of systems, or multiple hardware resources to support a single instance
of system. For example, a single disk drive can be partitioned and presented as
multiple disk drives to a compute system. Similarly, multiple disk drives can be
concatenated and presented as a single disk drive to a compute system.
Note: While deploying a data center, an organization may choose not to deploy
virtualization. In such an environment, the software-defined layer is deployed
directly over the physical infrastructure. Further, it is also possible that part of the
infrastructure is virtualized and rest is not virtualized.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 157
Modern Data Center Infrastructure Lesson
Software-Defined Infrastructure
Deployed either on virtual layer or
on physical layer
APPLICATIONS
Business
Applications
Internal Applications
Cloud
Extensibilit
Modern
Applications
Cloud
DATA CENTER INFRASTRUCTURE
All infrastructure components are
virtualized and aggregated into
pools.
MANAGEMENT
SERVICES
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined
Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Network
Backup and Archive
VIRTUAL INFRASTRUCTURE


Underlying resources are
abstracted from applications
Virtual Compute
Virtual Storage
Security Mechanisms
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Compute
Storage
Network
Replication
Governance, Risk,
and Compliance
Enables ITaaS
Centralized, automated, and policy-driven management and delivery of
heterogeneous resources
Components:

Software-defined compute

Software-defined storage

Software-defined network
Notes
The software-defined infrastructure layer is deployed either on the virtual layer or
on the physical layer. In the software-defined approach, all infrastructure
components are virtualized and aggregated into pools. This component abstracts
all underlying resources from applications.
The software-defined approach enables ITaaS, in which consumers provision all
infrastructure components as services. It centralizes and automates the
management and delivery of heterogeneous resources based on policies. The key
architectural components in the software-defined approach include softwaredefined compute (equivalent to compute virtualization), software-defined storage
(SDS), and software-defined network (SDN).
Information Storage and Management (ISM) v4
Page 158
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Orchestration
Component: orchestration
software, which provides:

Workflows for executing
automated tasks
APPLICATIONS
Internal Applications
Business
Applications
Interaction with various
components across layers and
functions to invoke provisioning
tasks
Cloud
Extensibilit
Clou
DATA CENTER INFRASTRUCTURE
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION

Modern
Applications
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined
Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
Network
Replication
Governance, Risk,
and Compliance
VIRTUAL INFRASTRUCTURE
Virtual Compute
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Compute
Storage
Notes
The orchestration layer includes the orchestration software. The key function of this
layer is to provide workflows for executing automated tasks to accomplish a wanted
outcome. Workflow refers to a series of interrelated tasks that perform a business
operation. The orchestration software enables this automated arrangement,
coordination, and management of the tasks. This function helps to group and
sequence tasks with dependencies among them into a single, automated workflow.
Associated with each service listed in the service catalog, there is an orchestration
workflow defined. When a service is selected from the service catalog, an
associated workflow in the orchestration layer is triggered. Based on this workflow,
the orchestration software interacts with the components across the softwaredefined layer and the BC, security, and management functions. This orchestration
entities executes the provisioning of tasks.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 159
Modern Data Center Infrastructure Lesson
Services
Delivers IT resources as services
to users:
APPLICATIONS
Internal Applications
Business
Applications
Modern
Applications
Cloud
Extensibilit
Cl
DATA CENTER INFRASTRUCTURE


Enables users to achieve
desired business results
Users have no liabilities
associated with owning the
resources
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
SECURITY
Service Catalog
ORCHESTRATION
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined
Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
VIRTUAL INFRASTRUCTURE
Virtual Compute
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Compute
Storage
Network
Replication
Governance, Risk,
and Compliance
Components:

Service catalog

Self-service portal
Functions of service layer:

Stores service information in service catalog and presents them to the users

Enables users to access services using a self-service portal
Notes
Similar to a cloud service, an IT service is a means of delivering IT resources to the
end users to enable them to achieve the desired business results and outcomes
without having any liabilities such as risks and costs associated with owning the
resources. Examples of services are application hosting, storage capacity, file
services, and email. The service layer is accessible to applications and end users.
This layer includes a service catalog that presents the information about all the IT
resources being offered as services. The service catalog is a database of
information about the services and includes various information about the services,
including the description of the services, the types of services, cost, supported
SLAs, and security mechanisms.
Information Storage and Management (ISM) v4
Page 160
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
The provisioning and management requests are passed on to the orchestration
layer, where the orchestration workflows—to fulfill the requests—are defined.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 161
Modern Data Center Infrastructure Lesson
Business Continuity
Enables ensuring the availability of
services in line with SLA
APPLICATIONS
Internal Applications
Business
Applications
Modern
Applications
Cloud
Extensibilit
Cl
DATA CENTER INFRASTRUCTURE
Supports all the layers to provide
uninterrupted services
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Software-Defined
Compute
Includes adoption of measures to
mitigate the impact of downtime
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
Network
Replication
Governance, Risk,
and Compliance
VIRTUAL INFRASTRUCTURE
Virtual Compute
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Management
Compute
Storage
Measure
Description
Proactive

Business impact analysis

Risk assessment

Technology solutions deployment (backup and replication)

Disaster recovery

Disaster restart
Reactive
Notes
The business continuity (BC) cross-layer function specifies the adoption of
proactive and reactive measures that enable an organization to mitigate the impact
of downtime due to planned and unplanned outages.
The proactive measures include activities and processes such as business impact
analysis, risk assessment, and technology solutions such as backup, archiving, and
replication.
The reactive measures include activities and processes such as disaster recovery
and disaster restart to be invoked in the event of a service failure.
Information Storage and Management (ISM) v4
Page 162
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
This function supports all the layers—physical, virtual, software-defined,
orchestration, and services—to provide uninterrupted services to the consumers.
The BC cross-layer function of a cloud infrastructure enables a business to ensure
the availability of services in line with the service level agreement (SLA).
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 163
Modern Data Center Infrastructure Lesson
Security
Supports all the layers to provide
secure services
APPLICATIONS
Internal Applications
Business
Applications
Modern
Applications
Cloud
Extensibilit
Cl
DATA CENTER INFRASTRUCTURE
Specifies the adoption of
administrative mechanisms
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE

Software-Defined
Compute
Security and personnel policies
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
Network
Replication
Governance, Risk,
and Compliance
VIRTUAL INFRASTRUCTURE

Virtual Compute
Standard procedures to direct
safe execution of operations
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Management
Compute
Storage
Specifies the adoption of technical
mechanisms

Firewall

Intrusion detection and prevention systems

Anti-virus
Security mechanisms enables organization to meet governance, risk, and
compliance (GRC) requirements
Notes
The security cross-layer function supports all the infrastructure layers—physical,
virtual, software-defined, orchestration, and service—to provide secure services to
the consumers. Security specifies the adoption of administrative and technical
mechanisms that mitigate or minimize the security threats and provide a secure
data center environment.
Administrative mechanisms include security and personnel policies or standard
procedures to direct the safe execution of various operations. Technical
mechanisms are usually implemented through tools or devices deployed on the IT
infrastructure. Examples of technical mechanisms include firewall, intrusion
detection and prevention systems, and anti-virus software.
Information Storage and Management (ISM) v4
Page 164
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Governance, risk, and compliance (GRC) specify processes that help an
organization in ensuring that their acts are ethically correct and in accordance with
their risk appetite (the risk level an organization chooses to accept), internal
policies, and external regulations.
Security mechanisms should be deployed to meet the GRC requirements. Security
and GRC are covered in Module, ‘Storage Infrastructure Security’.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 165
Modern Data Center Infrastructure Lesson
Management
Enables the following:
APPLICATIONS
Internal Applications


Storage infrastructure
configuration and capacity
provisioning
Business
Applications
Modern
Applications
Cloud
Extensibilit
Cl
DATA CENTER INFRASTRUCTURE
MANAGEMENT
SERVICE
BUSINESS
CONTINUITY
Self-Service Portal
ORCHESTRATION
SECURITY
Service Catalog
Orchestration
Software
SOFTWARE-DEFINED INFRASTRUCTURE
Problem resolution
Software-Defined
Compute
Software-Defined
Storage
Software-Defined
Network
Fault Tolerance
Mechanisms
Virtual Storage
Virtual Network
Backup and Archive
Security Mechanisms
Network
Replication
Governance, Risk,
and Compliance
VIRTUAL INFRASTRUCTURE

Capacity and availability
management

Compliance conformance

Monitoring services
Virtual Compute
PHYSICAL INFRASTRUCTURE (Do-It-Yourself/CONVERGED)
Storage
Operation
Management
Compute
Storage
Notes
The management cross-layer function specifies the adoption of activities related to
data center operations management. Adoption of these activities enables an
organization to align the creation and delivery of IT services to meet their business
objectives. This course focuses on the aspect of storage infrastructure
management.
Storage operation management enables IT administrators to manage the data
center infrastructure and services. Storage operation management tasks include
handling of infrastructure configuration, resource provisioning, problem resolution,
capacity, availability, and compliance conformance.
This function supports all the layers to perform monitoring, management, and
reporting for the entities of the infrastructure.
Information Storage and Management (ISM) v4
Page 166
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Do-It-Yourself Infrastructure
In the Do-It-Yourself
(DIY) approach,
organizations integrate
the best in class
infrastructure
components including
hardware and software
that is purchased from
different vendors.
This approach enables
the organizations to
use the advantages of
high-quality products
and services from the
respective leading
vendors and provides
specific functions with
more options and
configurations for
organizations to build
their cloud
infrastructure.
Vendor A Products
Router
Switc
h
Load Balancer
Vendor B Products
Storage
Server
Rack
Server
You can build the
infrastructure for cloud
in two methods using the do-it-yourself approach. The two methods are:

Greenfield

Brownfield
Notes
Two do-it-yourself approaches are:
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 167
Modern Data Center Infrastructure Lesson
Greenfield Method
Greenfield environments enable architects to design exactly what is required to
meet the business needs using new infrastructure that is built specifically for a
purpose. Greenfield environments can avoid some of the older and less efficient
processes, rules, methods, misconfigurations, constraints, and bottlenecks that
exist in the current environment. Greenfield environments also have the added
benefit of enabling a business to migrate infrastructure to a different technology or
vendor and to build in technologies that help avoid future lock-in. But greenfield
environments also have some downsides, such as higher cost, lack of staff
expertise, and possibly increased implementation time.
Brownfield Method
Brownfield involves upgrading or adding new cloud infrastructure elements to the
already existing infrastructure. This method allows organizations to repurpose the
existing infrastructure components, providing a cost benefit. Simultaneously the
organization may face integration issues, which can compromise the stability of the
overall system. Existing infrastructure or processes such as resource type,
available capacity, provisioning processes and managing the resources may place
extra constraints on the architect’s design. These constraints may negatively affect
performance or functionality.
Information Storage and Management (ISM) v4
Page 168
© Copyright 2019 Dell Inc.
Modern Data Center Infrastructure Lesson
Converged and Hyper-Converged Infrastructure
There are two types of converged systems; to learn more, click each tab.
Converged Infrastructure (CI)
CI brings together distinct infrastructure components into a single
package, including compute, network, storage, virtualization, and
management. They are hardware-focused systems where the compute
system access storage over a SAN.
The infrastructure components are integrated, tested, optimized, and delivered to
the customers as a single block. This solution offers single management software
capable of managing all of the components within the package.
Hyper-converged Infrastructure (HCI)
HCI offers efficiency using modular building blocks that are known as
nodes. A node consists of a server with Direct Attached Storage. They
are software-defined systems that decouple the compute, storage,
networking functions and run these functions on a common set of
physical resources. They do not have a physical Storage Area Network (SAN), or a
distinct physical storage controller like converged infrastructure.
The storage controller function runs as a software-based service on each compute
system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 169
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC VxBlock

Dell EMC VxRail

Dell EMC VxRack FLEX

Dell EMC VxRack SDDC

Dell EMC PowerEdge Server

Dell EMC XC Series Appliance

Dell Wyse Thin Clients

VMware Horizon

VMware ESXi

VMware Cloud Foundations
Information Storage and Management (ISM) v4
Page 170
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
Dell EMC VxBlock
Simplifies all aspects of IT and enables customers to modernize their infrastructure
and achieve better business outcomes faster. By seamlessly integrating enterpriseclass compute, network, storage, and virtualization technologies, it delivers most
advanced converged infrastructure. It is designed to support large-scale
consolidation, peak performance, and high availability for traditional and cloudbased workloads. It is a converged system optimized for data reduction and copy
data management. Customers can quickly deploy, easily scale, and manage your
systems simply and effectively. Deliver on both midrange and enterprise
requirements with the all-flash design, enterprise features, and support for a broad
spectrum of general-purpose workloads.
Dell EMC VxRail

Consists of the following software:
 VMware vSphere (ESXi, vCenter)
 VxRail Manager
 VMware vSAN

Consists of the following hardware:
 Nodes based on industry leading PowerEdge servers
 High density general purpose nodes

Designed, purchased, and supported as one product

Fastest growing hyper-converged system

Transforms VMware infrastructures by simplifying IT operations

Accelerates transformation
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 171
Concepts in Practice Lesson

Drives operational efficiency

Lowers capital and operational costs
Dell EMC VxRail Appliances are the fastest growing hyper-converged systems
worldwide. They are the standard for transforming VMware infrastructures,
dramatically simplifying IT operations while lowering overall capital and operational
costs.
It is important to remember that while VxRail is composed of many industry
standard components it is treated as a single entity. You don’t need to worry about
updating VMware or the PowerEdge microcode. That is all handled by VxRail. This
makes VxRail the simplest way to stand up VMware clusters. The details can make
VxRail seem more complex than it is. VxRail gives you VMware clusters. You can
run whatever runs on a normal VxRail cluster on a VxRail.
VxRail Appliances accelerate transformation and reduces risk with automated
lifecycle management. For example, users have to perform one-click for software
and firmware updates after deployment.
Drives operational efficiency for a 30% TCO advantage versus HCI systems built
using VSAN Ready Nodes. Unifies support for all VxRail hardware and software
delivering 42% lower total cost of serviceability.Engineered, manufactured,
managed, supported, and sustained as ONE for single end-to-end lifecycle
support.Fully loaded with enterprise data services for built-in data protection, cloud
storage, and disaster recovery.
Dell EMC VxRack FLEX
A Dell EMC engineered and manufactured rack-scale hyper-converged system that
delivers an unmatched combination of performance, resiliency and flexibility to
address enterprise data center needs. VxRack FLEX creates a server-based SAN
by combining virtualization software, known as VxFlex OS, with Dell EMC
PowerEdge servers to deliver flexible, scalable performance, and capacity on
demand. Local storage resources are combined to create a virtual pool of block
storage with varying performance tiers.
The architecture enables you to scale from as few as four nodes to over a
thousand nodes. In addition, it provides enterprise-grade data protection,
multitenant capabilities, and add-on enterprise features such as QoS, thin
provisioning, and snapshots. VxRack FLEX delivers the scalability, flexibility,
Information Storage and Management (ISM) v4
Page 172
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
performance, and time-to-value required to meet the demands of the modern
enterprise data center.
Dell EMC VxRack SDDC
The ultimate infrastructure foundation for realizing a multi-cloud vision. VxRack
SDDC creates IT certainty, improves service outcomes and reduces operational
risk by leveraging known, trusted technologies and operational processes.
Optimized for predictable performance, scalability, optimal user experience and
cost savings, VxRack SDDC delivers the simplest path to hybrid cloud with an
automated elastic cloud infrastructure at rack scale. The industry’s most advanced
integrated system for VMware Cloud Foundation, VxRack SDDC is a hyperconverged rack-scale system engineered with automation and serviceability
extensions offering integrated end to end lifecycle management and 24x7 single
vendor support.

Easily creates a foundation for a complete VMware private cloud

Fully integrated with VMware vSphere, vSAN, and NSX

Includes physical and virtual network infrastructure for multi-rack scaling and
growth

Automated management and serviceability extensions integrated with VMware
Cloud Foundation for single pane of glass management

Full lifecycle management and support for the entire engineered system
Dell EMC PowerEdge Server
As the foundation for a complete, adaptive and scalable solution, the 13th
generation of Dell EMC PowerEdge servers delivers outstanding operational
efficiency and top performance at any scale. It increases productivity with
processing power, exceptional memory capacity, and highly scalable internal
storage. PowerEdge provide insight from data, environment virtualization, and
enable a mobile workforce. Major benefits of PowerEdge Servers are:

Scalable Business Architecture: maximizes performance across the widest
range of applications with highly scalable architectures and flexible internal
storage.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 173
Concepts in Practice Lesson

Intelligent Automation: Automates the entire server lifecycle from deployment
to retirement with embedded intelligence that dramatically increases
productivity.

Integrated Security: Protects customers and business with a deep layer of
defense built into the hardware and firmware of every server.
Dell EMC XC Series Appliance
A hyper-converged appliance. It integrates with the Dell EMC PowerEdge servers,
the Nutanix software, and a choice of hypervisors to run any virtualized workload. It
is ideal for enterprise business applications, server virtualization, hybrid or private
cloud projects, and virtual desktop infrastructure (VDI). User can deploy an XC
Series cluster in 30 minutes and manage it without specialized IT resources. The
XC Series makes managing infrastructure efficient with a unified HTML5-based
management interface, enterprise-class data management capabilities, cloud
integration, and comprehensive diagnostics and analytics.
The features of Dell EMC XC Series are:

Available in flexible combinations of CPU, memory, and SSD/HDD

Includes thin provisioning and cloning, replication, and tiering

Dell EMC validates, tests, and supports globally

Able to grow one node at a time with nondisruptive, scale-out expansion
Dell Wyse Thin Clients
Dell offers a wide selection of secure, reliable, cost-effective Wyse thin clients
designed to integrate into any virtualized or web-based infrastructure, while
meeting the budget and performance requirements for any application. Wyse thin
and zero clients are built for easy integration into VDI or web-based environment
with instant, hands-free operation and performance that meets demands. Simplify
security and scalability with simple deployment and remote management in an
elegant, space-saving design. Malware-resistant and tailored for Citrix, Microsoft
and VMware.
Information Storage and Management (ISM) v4
Page 174
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
VMware Horizon
VMware Horizon is a VDI solution for delivering virtualized or hosted desktops and
applications through a single platform to the end users. These desktop and
application services—including RDS, hosted apps, packaged apps with VMware
ThinApp, and SaaS apps—can all be accessed from one unified workspace across
devices and locations. Horizon provides IT with a streamlined approach to deliver,
protect, and manage desktops and applications while containing costs and
ensuring that end users can work anytime, anywhere, on any device. Horizon
supports both Windows as well as Linux-based desktops.
VMware ESXi
VMware ESXi is a bare-metal hypervisor. ESXi has a compact architecture that is
designed for integration directly into virtualization-optimized compute system
hardware, enabling rapid installation, configuration, and deployment. ESXi
abstracts processor, memory, storage, and network resources into multiple VMs
that run unmodified operating systems and applications. The ESXi architecture
comprises underlying operating system called VMkernel, that provides a means to
run management applications and VMs. VMkernel controls all hardware resources
on the compute system and manages resources for the applications. It provides
core OS functionality, such as process management, file system, resource
scheduling, and device drivers.
VMware Cloud Foundation
VMware Cloud Foundation makes it easy to deploy and run a hybrid cloud. It
provides integrated cloud infrastructure (compute, storage, networking, and
security) and cloud management services to run enterprise applications in both
private and public environments.
Cloud Foundation provides a complete set of software-defined services for
compute, storage, networking and security, and cloud management to run
enterprise apps - traditional or containerized - in private or public environments.
Cloud Foundation simplifies the path to the hybrid cloud by delivering a single
integrated solution that is easy to operate with integrated automated life cycle
management. Cloud Foundation is built on VMware’s leading hyperconverged
architecture (vSAN) with all-flash performance and enterprise-class storage
services including deduplication, compression, and erasure coding. vSAN
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 175
Concepts in Practice Lesson
implements hyperconverged storage architecture delivers elastic storage and
drastically simplifies storage management.
Cloud Foundation delivers end to end security for all applications by delivering
microsegmentation, distributed firewalls, and VPN (NSX), VM, hypervisor, and
vMotion encryption (vSphere), and data at rest, cluster, and storage encryption
(vSAN).
Cloud Foundation delivers self-driving operations (vRealize Operations, vRealize
Log Insight) from applications to infrastructure to help organizations plan, manage,
and scale their SDDC. Users can perform application-aware monitoring and
troubleshooting along with automated and proactive workload management,
balancing, and remediation. It automatically deploys all of the building blocks of the
Software-Defined Data Center: compute, storage, networking, and cloud
management.
Information Storage and Management (ISM) v4
Page 176
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. Which cross-layer function enables an organization to mitigate the impact of
downtime?
A. Security
B. Service
C. Business continuity
D. Management
2. Which layer function provides workflows for executing automated tasks to
accomplish a wanted outcome?
A. Orchestration
B. Security
C. Services
D. Management
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 177
Summary
Summary
Information Storage and Management (ISM) v4
Page 178
© Copyright 2019 Dell Inc.
Intelligent Storage Systems
Introduction
This module focuses on the key components of an intelligent storage system. This
module also focuses on storage subsystems and provides details on components,
addressing, and performance parameters of a hard disk drive (HDD),solid state
drive (SSD) and hybrid storage drives. Then, this module focuses on RAID
techniques and their use to improve performance and protection. Finally, this
module focuses on the types of intelligent storage systems and their architectures.
Upon completing this module, you will be able to:




Describe the key components of an intelligent storage system
Describe hard disk drive, solid-state drive, and hybrid drive components
Describe RAID techniques
Discuss the types of intelligent storage systems
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 179
Components of Intelligent Storage Systems Lesson
Components of Intelligent Storage Systems Lesson
Introduction
This lesson covers components of intelligent storage systems. This lesson also
covers components, addressing, and performance of hard disk drives, solid state
drives and Hybrid drives.
This lesson covers the following topics:

List the components of intelligent storage systems

Explain hard disk drive, solid-state drive, and hybrid drive components
Information Storage and Management (ISM) v4
Page 180
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
ISMv4 Source - Intelligent Storage Systems - Components
Video: Components of Intelligent Storage System
The video is located at
https://edutube.emc.com/Player.aspx?vno=8xUkRMX6cXIsfToijT6gaw
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 181
Components of Intelligent Storage Systems Lesson
What Is an Intelligent Storage System?
Definition: Intelligent Storage System
A feature-rich storage array that provides highly optimized I/O
processing capabilities.

Has a purpose-built operating environment that provides intelligent resource
management capability

Provides large amount of cache

Provides multiple I/O paths
Key Features of ISS:

Supports combination of HDD and SS

Service massive amount of IOPS

Scale-out architecture

Deduplication, compression, and encryption

Automated storage tiering

Virtual storage provisioning

Supports APIs to integrate with SDDC and cloud

Data Protection
Notes
Intelligent storage systems are feature-rich storage arrays that provide highly
optimized I/O processing capabilities. These intelligent storage systems have the
capability to meet the requirements of today’s I/O intensive modern applications.
These applications require high levels of performance, availability, security, and
scalability.
Therefore, to meet the requirements of the applications, many vendors of intelligent
storage systems now support SSDs, hybrid drives, encryption, compression,
deduplication, and scale-out architecture.
Information Storage and Management (ISM) v4
Page 182
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
The storage systems have an operating environment that intelligently and optimally
handles the management, provisioning, and utilization of storage resources. The
storage systems are configured with a large amount of memory (called cache) and
multiple I/O paths and use sophisticated algorithms to meet the requirements of
performance-sensitive applications. The storage systems also support various
technologies such as automated storage tiering and virtual storage provisioning.
These capabilities have added a new dimension to storage system performance.
Further, the intelligent storage systems support APIs to enable integration with
SDDC and cloud environments.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 183
Components of Intelligent Storage Systems Lesson
ISS Components
Information Storage and Management (ISM) v4
Page 184
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Storage
Controller(s)
Intelligent Storage System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 185
Components of Intelligent Storage Systems Lesson
Two key components of an ISS:
Controller
Storage

Block-based

All HDDs

File-based

All SSDs

Object-based

Combination of both

Unified
Notes
An intelligent storage system has two key components, controller and storage. A
controller is a compute system that runs a purpose-built operating system that is
responsible for performing several key functions for the storage system. Examples
of such functions are serving I/Os from the application servers, storage
management, RAID protection, local and remote replication, provisioning storage,
automated tiering, data compression, data encryption, and intelligent cache
management. An intelligent storage system typically has more than one controller
for redundancy. Each controller consists of one or more processors and a certain
amount of cache memory to process a large number of I/O requests. These
controllers are connected to the compute system either directly or via a storage
network. The controllers receive I/O requests from the compute systems that are
read or written from/to the storage by the controller. Depending on the type of the
data access method used for a storage system, the controller can either be
classified as block-based, file-based, object-based, or unified. An storage system
can have all hard disk drives, all solid state drives, or a combination of both.
Information Storage and Management (ISM) v4
Page 186
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Hard Disk Drive Components
A hard disk drive is a persistent storage device that stores and retrieves data using
rapidly rotating disks (platters) coated with magnetic material.
Controller
Board
HDA
Platter and
Read/Write
Head
Power
Connectors
Interface
The key components of a hard disk drive (HDD) are:

Platter

Spindle

Read/write head

Actuator arm assembly

Controller board
Notes
I/O operations in hard drives are performed by rapidly moving the arm across the
rotating flat platters that are coated with magnetic material.
Data is transferred between the disk controller and magnetic platters through the
read/write (R/W) head which is attached to the arm. Data can be recorded and
erased on magnetic platters any number of times.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 187
Components of Intelligent Storage Systems Lesson
Platter
A typical hard disk drive consists of one or more flat circular disks called platters.
The data is recorded on these platters in binary codes (0s and 1s). The set of
rotating platters is sealed in a case, called Head Disk Assembly (HDA). A platter is
a rigid, round disk coated with magnetic material on both surfaces (top and
bottom).
The data is encoded by polarizing the magnetic area or domains of the disk
surface. Data can be written to or read from both surfaces of the platter. The
number of platters and the storage capacity of each platter determine the total
capacity of the drive.
Spindle
A spindle connects all the platters and is connected to a motor. The motor of the
spindle rotates with a constant speed. The disk platter spins at a speed of several
thousands of revolutions per minute (rpm).
Read/Write head
Read/write (R/W) heads, read and write data from or to the platters. Drives have
two R/W heads per platter, one for each surface of the platter. The R/W head
changes the magnetic polarization on the surface of the platter when writing data.
While reading data, the head detects the magnetic polarization on the surface of
the platter.
During reads and writes, the R/W head senses the magnetic polarization and never
touches the surface of the platter. When the spindle rotates, a microscopic air gap
is maintained between the R/W heads and the platters, known as the head flying
height. This air gap is removed when the spindle stops rotating and the R/W head
rests on a special area on the platter near the spindle. This area is called the
landing zone
Actuator Arm Assembly
R/W heads are mounted on the actuator arm assembly, which positions the R/W
head at the location on the platter where the data needs to be written or read. The
R/W heads for all platters on a drive are attached to one actuator arm assembly
and move across the platters simultaneously.
Information Storage and Management (ISM) v4
Page 188
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Drive Controller Board
The controller is a printed circuit board, mounted at the bottom of a disk drive. It
consists of a microprocessor, internal memory, circuitry, and firmware.
The firmware controls the power supplied to the spindle motor as well as controls
the speed of the motor. It also manages the communication between the drive and
the compute system.
In addition, it controls the R/W operations by moving the actuator arm and
switching between different R/W heads, and performs the optimization of data
access.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 189
Components of Intelligent Storage Systems Lesson
Physical Disk Structure and Logical Block Addressing
Sector
Spindle
Sector
Track
Cylinder
Platter
Track
In the illustration, the drive shows eight sectors per track, six heads, and four cylinders. This means
a total of 8 × 6 × 4 = 192 blocks. The block number ranges from 0 to 191. Each block has its own
unique address. Assuming that the sector holds 512 bytes, a 500 GB drive with a formatted capacity
of 465.7 GB has in excess of 976,000,000 blocks.
Notes
Data on the disk is recorded on tracks, which are concentric rings on the platter
around the spindle. The tracks are numbered, starting from zero, from the outer
edge of the platter. The number of tracks per inch (TPI) on the platter (or the track
density) measures how tightly the tracks are packed on a platter.
Each track is divided into smaller units called sectors. A sector is the smallest,
individually addressable unit of storage. The track and sector structure is written on
the platter by the drive manufacturer using a low-level formatting operation. The
number of sectors per track varies according to the drive type. Typically, a sector
holds 512 bytes of user data. Besides user data, a sector also stores other
information, such as the sector number, head number or platter number, and track
number. This information helps the controller to locate the data on the drive.
A cylinder is a set of identical tracks on both surfaces of each drive platter. The
location of R/W heads is referred to by the cylinder number, not by the track
number. Earlier drives used physical addresses consisting of cylinder, head, and
sector (CHS) number. These addresses referred to specific locations on the disk,
and the OS had to be aware of the geometry of each disk used.
Information Storage and Management (ISM) v4
Page 190
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Logical block addressing (LBA) has simplified the addressing by using a linear
address to access physical blocks of data. The disk controller translates LBA to a
CHS address; the compute system needs to know only the size of the disk drive in
terms of the number of blocks. The logical blocks are mapped to physical sectors
on a 1:1 basis.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 191
Components of Intelligent Storage Systems Lesson
HDD Performance

A disk drive is an electromechanical device that governs the overall
performance of the storage system environment

The various factors that affect the performance of disk drives are:
 Seek time
 Rotational latency
 Disk transfer rate

Disk service time = Seek time + Rotational latency + Data transfer rate
Information Storage and Management (ISM) v4
Page 192
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Seek Time
Radial
Movement

The time to position the read/write head

The lower the seek time, the faster the I/O operation

Seek time specifications include:
 Full stroke
 Average
 Track-to-track

The drive manufacturer specifies seek time of a disk
Notes
The seek time (also called access time) describes the time taken to position the
R/W heads across the platter with a radial movement (moving along the radius of
the platter). In other words, it is the time taken to position and settle the arm and
the head over the correct track. Therefore, the lower the seek time, the faster the
I/O operation.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 193
Components of Intelligent Storage Systems Lesson
Disk vendors publish the following seek time specifications:

Full Stroke: It is the time taken by the R/W head to move across the entire width
of the disk, from the innermost track to the outermost track.

Average: It is the average time taken by the R/W head to move from one
random track to another, normally listed as the time for one-third of a full stroke.

Track-to-Track: It is the time taken by the R/W head to move between adjacent
tracks.
Each of these specifications is measured in milliseconds (ms). The seek time of a
disk is typically specified by the drive manufacturer. The average seek time on a
modern disk is typically in the range of 3 to 15 ms. Seek time has more impact on
the I/O operation of random tracks rather than the adjacent tracks.
To minimize the seek time, data can be written to only a subset of the available
cylinders. This results in lower usable capacity than the actual capacity of the drive.
For example, a 500 GB disk drive is set up to use only the first 40 percent of the
cylinders and is effectively treated as a 200 GB drive. This is known as shortstroking the drive.
Information Storage and Management (ISM) v4
Page 194
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Rotational Latency

The time the platter takes to rotate and position
the data under the R/W head

Depends on the rotation speed of the spindle

Average rotational latency: One-half of the time
taken for a full rotation
Notes
To access data, the actuator arm moves the R/W
head over the platter to a particular track while the
platter spins to position the requested sector under
the R/W head. The time taken by the platter to rotate and position the data under
the R/W head is called rotational latency.
This latency depends on the rotation speed of the spindle and is measured in
milliseconds. The average rotational latency is one-half of the time taken for a full
rotation. Similar to the seek time, rotational latency has more impact on the
reading/writing of random sectors on the disk than on the same operations on
adjacent sectors.
Average rotational latency is approximately 5.5 ms for a 5,400-rpm drive, and
around 2 ms for a 15,000-rpm drive.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 195
Components of Intelligent Storage Systems Lesson
Data Transfer Rate
Average amount of data per unit time that the drive can deliver to the HBA :

Internal transfer rate: Speed at which data moves from the surface of a platter
to the internal buffer of the disk

External transfer rate: Rate at which data move through the interface to the
HBA
HBA
Interface
Head Disk
Assembly
Buffer
Internal transfer rate
measured here
External transfer Rate
measured here
Disk Drive
Notes
The data transfer rate (also called transfer rate) refers to the average amount of
data per unit time that the drive can deliver to the HBA. In a read operation, the
data first moves from disk platters to R/W heads; then it moves to the drive’s
internal buffer. Finally, data moves from the buffer through the interface to the
compute system’s HBA.
In a write operation, the data moves from the HBA to the internal buffer of the disk
drive through the drive’s interface. The data then moves from the buffer to the R/W
heads. Finally, it moves from the R/W heads to the platters. The data transfer rates
during the R/W operations are measured in terms of internal and external transfer
rates.
Internal transfer rate is the speed at which data moves from a platter’s surface to
the internal buffer (cache) of the disk. The internal transfer rate takes into account
factors such as the seek time and rotational latency. External transfer rate is the
rate at which data can move through the interface to the HBA.
Information Storage and Management (ISM) v4
Page 196
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
The external transfer rate is generally the advertised speed of the interface, such
as 133 MB/s for ATA.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 197
Components of Intelligent Storage Systems Lesson
I/O Controller Utilization vs. Response Time

Based on fundamental laws of disk drive performance

For performance-sensitive applications disks are commonly utilized below 70%
of their I/O serving capability
Knee of curve: disks at about
70% utilization
Response Time
(ms)
0%
Low Queue Size
Utilization
70%
100%
Notes
The utilization of a disk I/O controller has a significant impact on the I/O response
time. Consider that a disk is viewed as a black box consisting of two elements: the
queue and the disk I/O controller. Queue is the location where an I/O request waits
before it is processed by the I/O controller and disk I/O controller processes I/Os
waiting in the queue one by one.
The I/O requests arrive at the controller at the rate generated by the application.
The I/O arrival rate, the queue length, and the time taken by the I/O controller to
process each request determines the I/O response time. If the controller is busy or
heavily utilized, the queue size will be large and the response time will be high.
As the utilization reaches 100 percent, that is, as the I/O controller saturates, the
response time moves closer to infinity. In essence, the saturated component or the
bottleneck forces the serialization of I/O requests; meaning, each I/O request must
wait for the completion of the I/O requests that preceded it.
Information Storage and Management (ISM) v4
Page 198
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 199
Components of Intelligent Storage Systems Lesson
Solid State Drive Components

Solid state drives (SSDs) are:
 Storage devices that contain non-volatile flash memory

Internally, a solid state drive’s hardware architecture consists of the following
components:
 I/O interface
 Controller
 Mass storage

The I/O interface enables connecting the power and data connectors to the
solid state drives.

Solid state drives typically support standard connectors such as SATA, SAS, or
FC.
Flash Memory
Flash Memory
Flash Memory
RAM Cache
Flash Memory
I/O
Interfaces
Drive Controller
Non-Volatile Memory
Flash Memory
Flash Memory
Controller
Mass Storage
The I/O interface enables connecting the power and data connectors to the solid
state drives.
Information Storage and Management (ISM) v4
Page 200
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Notes
Solid state drives are especially well suited for low-latency applications that require
consistent, low (less than 1 millisecond) read/write response times.
An HDD servicing small-block, highly-concurrent, and random workloads involves
considerable rotational and seek latency, which significantly reduces throughput.
Externally, solid state drives have the same physical format and connectors as
mechanical hard disk drive. This uniformity maintains the compatibility in both form
and format with mechanical hard disk drives. It also allows for easy replacement of
a mechanical drive with a solid state drive.
The controller includes a drive controller, RAM, and non-volatile memory (NVRAM).
The drive controller manages all drive functions.
The non-volatile RAM (NVRAM) is used to store the SSD’s operational software
and data. Not all SSDs have separate NVRAM. Some models store their programs
and data to the drive’s mass storage.
The RAM is used in the management of data being read and written from the SSD
as a cache, and for the SSD’s operational programs and data. SSDs include many
features such as encryption and write coalescing.
The mass storage is an array of non-volatile memory chips. They retain their
contents when powered off. These chips are commonly called Flash memory. The
number and capacity of the individual chips vary directly in relationship to the
SSD’s capacity. The larger the capacity of the SSD, the larger is the capacity and
the greater is the number of the Flash memory chips.
SSDs consume less power compared to hard disk drives. Because SSDs do not
have moving parts, they generate less heat compared to HDDs. Therefore, it
further reduces the need for cooling in storage enclosure, which further reduces the
overall system power consumption.
SSDs have multiple parallel I/O channels from its drive controller to the flash
memory storage chips. Generally, the larger the number of flash memory chips in
the drive, the larger is the number of channels.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 201
Components of Intelligent Storage Systems Lesson
SSD Addressing
Solid state memory chips have different capacities, for example a solid state
memory chip can be 32 GB or 4 GB per chip. However, all memory chips share the
same logical organization, that is pages and blocks.
8 KB write to SSD
Logically mapped to pages (SSD
metadata)
Saved as two 4KB pages
LBA 0 x 3000
LBA 0 x 2000
128KB Block (32 x
4KB pages)
4KB Page
Notes
At the lowest level, a solid state drive stores bits. Eight bits make up a byte, and
while on the typical mechanical hard drive 512 bytes would make up a sector, solid
state drives do not have sectors. Solid state drives have a similar physical data
object called a page.Solid state memory chips have different capacities, for
example a solid state memory chip can be 32 GB or 4 GB per chip. However, all
memory chips share the same logical organization, that is pages and blocks.
Like a mechanical hard drive sector, the page is the smallest object that can be
read or written on a solid state drive. Unlike mechanical hard drives, pages do not
have a standard capacity. A page’s capacity depends on the architecture of the
solid state memory chip. Typical page capacities are 4 KB, 8 KB, and 16 KB.
A solid state drive block is made up of pages. A block may have 32, 64, or 128
pages. 32 is a common block size. The total capacity of a block depends on the
solid state chip’s page size. Only entire blocks may be written or erased on a solid
state memory chip.
Information Storage and Management (ISM) v4
Page 202
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Individual pages may be read or invalidated (a logical function). For a block to be
written, pages are assembled into full blocks in the solid state drive’s cache RAM
and then written to the block storage object.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 203
Components of Intelligent Storage Systems Lesson
Flash Memory Page States
A page has three possible states, erased (empty), valid, and invalid.
Start
Erased
Write
Erase
(Electrical)
Invalid
Valid
(Re)Write
or
Delete
Notes
In order to write any data to a page, its owning block location on the flash memory
chip must be electrically erased. This function is performed by the SSD’s hardware.
Once a page has been erased, new data can be written to it.
For example: when a 4 KB of data is written to a 4 KB capacity page, the state of
that page is changed to valid, as it is holding valid data. A valid page’s data can be
read any number of times. If the drive receives a write request to the valid page,
the page is marked invalid and that write goes to another page. This is because
erasing blocks is time consuming and may increase the response time.
Once a page is marked invalid, its data can no longer be read. An invalid page
needs to be erased before it can once again be written with new data. Garbage
collection handles this process. Garage collection is the process of providing new
erased blocks.
Information Storage and Management (ISM) v4
Page 204
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
SDD Performance

Access type
 SSD performs random reads the best
 SSDs use all internal I/O channels in parallel for multithreaded large block
I/Os

Drive state
 New SSD or SSD with substantial unused capacity offers best performance

Workload duration
 SSDs are ideal for most workloads
Notes
Solid state drives are semiconductor, random-access devices; these result in very
low response times compared to hard disk drives. This, combined with the multiple
parallel I/O channels on the back end, gives SSDs performance characteristics that
are better than hard drives.SSD performance is dependent on access type, drive
state, and workload duration. SSD performs random reads the best.
In carefully tuned multi-threaded, small-block random I/O workload storage
environments, SSDs can deliver much lower response times and higher throughput
than hard drives. Because they are random access devices, SSDs pay no penalty
for retrieving I/O that is stored in more than one area; as a result their response
time is in an order of magnitude faster than the response time of hard drives.
A new SSD or an SSD with substantial unused capacity has the best performance.
Drives with substantial amounts of their capacity consumed will take longer to
complete the read-modify-write cycle. SSDs are best for workloads with short
bursts of activity.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 205
Components of Intelligent Storage Systems Lesson
Solid State Hybrid Drive
Definition: Solid-State Hybrid Drive
Hybrid storage technologies combine NAND flash memory or SSDs,
with the HDD technology.
NAND
Flash
Memory
HDD
Optimized performance is ensured by placing "hot data", or data that is most
directly associated with improved performance, on the "faster" part of the storage
architecture.
Information Storage and Management (ISM) v4
Page 206
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Notes
In SSHDs the data elements that are associated with performance, such as most
frequently accessed data items, are stored in the NAND flash memory. This
method provides a significant performance improvement over traditional hard
drives.
In hybrid storage technology, the objective is to achieve a balance of improved
performance and high-capacity storage availability by combining hard drives and
SSD.
Optimized performance is ensured by placing "hot data", or data that is most
directly associated with improved performance, on the "faster" part of the storage
architecture.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 207
Components of Intelligent Storage Systems Lesson
Non-Volatile Memory Express (NVMe)
Definition: NVMe
NVMe (Non-Volatile Memory Express) is a new device interface for
Non-Volatile Memory (NVM) storage technologies using PCIe
connectivity.

A standard developed by an open industry consortium, directed by a 13
company promoter group which includes Dell

Core design objective is to achieve high levels of parallelism, concurrency, and
scalability and realize the performance benefits of NAND flash and emerging
Storage Class Memory (SCM)
Notes
NVM stands for non-volatile memory such as NAND flash memory. NVMe has
been designed to capitalize on the low latency and internal parallelism of solid-state
storage devices.
The previous interface protocols like SCSI were developed for use with far slower
hard disk drives where a very lengthy delay exists between a request and data
transfer, where data speeds are much slower than RAM speeds, and where disk
rotation and seek time give rise to further optimization requirements.
NVMe is a command set and associated storage interface standards that specify
efficient access to storage devices and systems based on Non-Volatile Memory
(NVM) media. NVMe is broadly applicable to NVM storage technology, including
current NAND-based flash and higher-performance, Storage Class Memory (SCM).
Information Storage and Management (ISM) v4
Page 208
© Copyright 2019 Dell Inc.
Components of Intelligent Storage Systems Lesson
Storage Class Memory (SCM)
Definition: Storage Class Memory
A solid-state memory that blurs the boundaries between storage and
memory by being low-cost, fast, and nonvolatile.
Features:

Non-volatile

Short access time like DRAM

Low cost per bit like disk

Solid-state, no moving parts
Notes
Despite the emergence of flash storage and more recently, the NVMe stack,
external storage systems are still orders of magnitude slower than server memory
technologies (RAM). They can also be a barrier to achieving the highest end-to-end
system performance.
The memory industry has been aiming towards something that has the speed of
DRAM but the capacity, cost, and persistence of NAND flash memory. The shift
from SATA to faster interfaces such as SAS and PCI-Express using the NVMe
protocol has made SSDs much faster, but nowhere near the speed of DRAM.
Now, a new frontier in storage media bridges the latency gap between server
storage and external storage: storage-class memory (SCM). This new class of
memory technology has performance characteristics that fall between DRAM and
flash characteristics. Figure highlights where SCM fits into the storage media
hierarchy.
SCM is slower than DRAM but read and write speeds are over 10 times faster than
flash and can support higher IOPS while offering comparable throughput.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 209
Components of Intelligent Storage Systems Lesson
Furthermore, data access in flash is at the block and page levels, but SCM can be
addressed at the bit or word level. This granularity eliminates the need to erase an
entire block to program it, and it also simplifies random access.
However, because the price per gigabyte is expected to be substantially higher,
SCM is unlikely to be a replacement for flash in enterprise storage. With new
storage media, price per gigabyte is a key contributor to adoption. For example, in
spite of the clear advantages of flash over HDDs, the industry hasn’t yet completely
converted from HDDs to flash.
Other persistent memory technologies are also in development, some with the
potential for broad adoption in enterprise and embedded applications, such as
nanotube RAM (NRAM) and resistive RAM (ReRAM).
Information Storage and Management (ISM) v4
Page 210
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
RAID Techniques Lesson
Introduction
This lesson covers RAID and its use to improve performance and protection. It
covers various RAID implementations, techniques, and levels commonly used.
This lesson also covers the erasure coding technique and its advantages.
This lesson covers the following topics:

Describe RAID techniques and implementation methods

Describe commonly used RAID levels

Compare RAID levels based on their cost, performance,and protection
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 211
RAID Techniques Lesson
RAID Techniques
RAID Overview
Definition: RAID (Redundant Array of Independent Disks)
A technique that combines multiple disk drives into a logical unit
(RAID set) and provides protection, performance, or both.

Provides data protection against drive failures

Improves storage system performance by serving I/Os from multiple drives
simultaneously

Two implementation methods
 Software RAID
 Hardware RAID
Notes
RAID is a technique in which multiple disk drives are combined into a logical unit
called a RAID set and data is written in blocks across the disks in the RAID set.
RAID protects against data loss when a drive fails, by using redundant drives and
parity. RAID also helps in improving the storage system performance as read and
write operations are served simultaneously from multiple disk drives.
RAID is typically implemented by using a specialized hardware controller present
either on the compute system or on the storage system. The key functions of a
RAID controller are: management and control of drive aggregations, translation of
I/O requests between logical and physical drives, and data regeneration in the
event of drive failures.
Information Storage and Management (ISM) v4
Page 212
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
Software RAID uses compute system-based software to provide RAID functions
and is implemented at the operating-system level. Software RAID implementations
offer cost and simplicity benefits when compared with hardware RAID.
However, they have the following limitations:

Performance: Software RAID affects the overall system performance. This is
due to additional CPU cycles required to perform RAID calculations.

Supported features: Software RAID does not support all RAID levels.

Operating system compatibility: Software RAID is tied to the operating system;
hence, upgrades to software RAID or to the operating system should be
validated for compatibility. This leads to inflexibility in the data-processing
environment.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 213
RAID Techniques Lesson
RAID Array Components
A RAID array is an enclosure that contains various disk drives and supporting
hardware to implement RAID.
A subset of disks within a RAID array can be grouped to form logical associations
called logical arrays, also known as a RAID set or a RAID group.
VM
VM
Logical Array
(RAID Sets)
Hypervisor
RAID Controller
Compute System
Hard Disks
RAID Array
Information Storage and Management (ISM) v4
Page 214
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
RAID Techniques
Three different RAID techniques form the basis for defining various RAID levels;
they are:
Striping
VM
Mirroring
VM
VM
Hypervisor
A
RAID Controller
Parity
VM
VM
Hypervisor
Hypervisor
A
A
RAID Controller
RAID Controller
D1
A1
A3
A2
A4
Strip
Stripe
A
VM
A1
A
D2
A2
P
D3
Ap
A3
Rebuilding data of the failed D3 drive:
D1 + D2 + ? =
P =P – D1 – D2
D3
Notes
Striping
Striping is a technique of spreading data across multiple drives (more than one) in
order to use the drives in parallel. All the read/write heads work simultaneously,
allowing more data to be processed in a shorter time and increasing performance,
compared to reading and writing from a single disk. Within each disk in a RAID set,
a predefined number of contiguously addressable disk blocks are defined as strip.
The set of aligned strips that spans across all the disks within the RAID set is called
a stripe. The illustration shows representations of a striped RAID set. Strip size
(also called stripe depth) describes the number of blocks in a strip (represented as
“A1, A2, A3, and A4”). The maximum amount of data that can be written to or read
from a single disk in the set, assuming that the accessed data starts at the
beginning of the strip.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 215
RAID Techniques Lesson
All strips in a stripe have the same number of blocks. Having a smaller strip size
means that the data is broken into smaller pieces while it is spread across the
disks. Stripe size (represented as A) is a multiple of strip size by the number of
data disks in the RAID set.
For example: in a four-disk striped RAID set with a strip size of 64KB, the stripe
size is 256 KB (64KB x 4). In other words, A = A1 +A2 + A3 + A4. Stripe width
refers to the number of data strips in a stripe. Striped RAID does not provide any
data protection unless parity or mirroring is used.
Mirroring
Mirroring is a technique whereby the same data is stored on two different disk
drives, yielding two copies of the data. If one disk drive failure occurs, the data
remains intact on the surviving disk drive and the controller continues to service the
compute system’s data requests from the surviving disk of a mirrored pair.
When the failed disk is replaced with a new disk, the controller copies the data from
the surviving disk of the mirrored pair. This activity is transparent to the compute
system. In addition to providing complete data redundancy, mirroring enables fast
recovery from disk failure. However, disk mirroring provides only data protection
and is not a substitute for data backup.
Mirroring constantly captures changes in the data, whereas a backup captures
point-in-time images of the data. Mirroring involves duplication of data – the amount
of storage capacity needed is twice the amount of data being stored. Therefore,
mirroring is considered expensive and is preferred for mission-critical applications
that cannot afford the risk of any data loss. Mirroring improves read performance
because read requests can be serviced by both disks.
However, write performance is slightly lower than that in a single disk because
each write request manifests as two writes on the disk drives. Mirroring does not
deliver the same levels of write performance as a striped RAID.
Parity
Parity is a method to protect striped data from disk drive failure without the cost of
mirroring. An additional disk drive is added to hold parity, a mathematical construct
that allows re-creation of the missing data. Parity is a redundancy technique that
ensures protection of data without maintaining a full set of duplicate data.
Information Storage and Management (ISM) v4
Page 216
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
Calculation of parity is a function of the RAID controller. Parity information can be
stored on separate, dedicated disk drives, or distributed across all the drives in a
RAID set. The first three disks in the figure, labeled D1 to D3, contain the data. The
fourth disk, labeled P, stores the parity information, which, in this case, is the sum
of the elements in each row. Now, if one of the data disks fails, the missing value
can be calculated by subtracting the sum of the rest of the elements from the parity
value. In the diagram, for simplicity, the computation of parity is represented as an
arithmetic sum of the data. However, parity calculation is a bitwise XOR operation.
Compared to mirroring, parity implementation considerably reduces the cost
associated with data protection. Consider an example of a parity RAID
configuration with four disks where three disks hold data, and the fourth holds the
parity information. In this example, parity requires only 33 percent extra disk space
compared to mirroring, which requires 100 percent extra disk space.
However, there are some disadvantages of using parity. Parity information is
generated from data on the data disk. Therefore, parity is recalculated every time
there is a change in data. This recalculation is time-consuming and affects the
performance of the RAID array.
For parity RAID, the stripe size calculation does not include the parity strip.
For example: in a four (3 + 1) disk parity RAID set with a strip size of 64 KB, the
stripe size will be 192 KB (64KB x 3).
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 217
RAID Techniques Lesson
RAID Levels
Commonly used RAID levels are:

RAID 0 – Striped set with no fault tolerance

RAID 1 – Disk mirroring

RAID 1 + 0 – Mirroring and Striping RAID

RAID 3 - Striped set with parallel access and dedicated parity

RAID 5 – Striped set with independent disk access and a distributed parity

RAID 6 – Striped set with independent disk access and dual distributed parity
The RAID level selection depends on the parameters such as application
performance, data availability requirements, and cost.
These RAID levels are defined based on striping, mirroring, and parity techniques.
Some RAID levels use a single technique, whereas others use a combination of
techniques.
The commonly used RAID levels are RAID 0, RAID 1, 3, 5, 6 and 1+0.
Information Storage and Management (ISM) v4
Page 218
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
Video: RAID
The video is located at
https://edutube.emc.com/Player.aspx?vno=41vs6WVDSGBt6uD6g2erTw
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 219
RAID Techniques Lesson
RAID 0
RAID 0 configuration uses data striping techniques, where data is striped across all
the disks within a RAID set.
C
B
A
Data from compute
system
RAID Controller
A1
A2
B1
B2
C1
C2
A4
A5
B3
B4
B5
C3
C4
C5
A3
Data Disks
Notes
RAID 0 utilizes the full storage capacity of a RAID set.
To read data, all the strips are gathered by the controller. When the number of
drives in the RAID set increases, the performance improves because more data
can be read or written simultaneously.
RAID 0 is a good option for applications that need high I/O throughput. However, if
these applications require high availability during drive failures, RAID 0 does not
provide data protection and availability.
Information Storage and Management (ISM) v4
Page 220
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
RAID 1
A RAID 1 set consists of two disk drives and every write is written to both disks.
Data from
compute
system
C
B
A
Notes
In RAID 1, the mirroring is transparent
to the compute system. During disk
failure, the impact on data recovery in
RAID 1 is the least among all RAID
implementations. This is because the
RAID controller uses the mirror drive
for data recovery.
RAID Controller
RAID 1 is suitable for applications that
require high availability and cost is not
a constraint.
A
A
B
B
C
C
Mirror Set
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 221
RAID Techniques Lesson
RAID 1+0 (Mirroring and Striping)
Most data centers require data redundancy and performance from their RAID
arrays.
RAID 1+0 combines the performance benefits of RAID 0 with the redundancy
benefits of RAID 1.
C
B
A
Data from compute
system
RAID
Controller
Striping
Mirroring
A1
A1
Mirroring
Mirroring
A2
A2
A3
A3
B1
B1
B2
B2
B3
B3
C1
C1
C2
C2
C3
C3
Mirror Set A
Mirror Set B
Mirror Set C
Notes
RAID 1+0 uses mirroring and striping techniques and combines their benefits. This
RAID type requires an even number of disks, the minimum being four.
RAID 1+0 is also known as RAID 10 (Ten) or RAID 1/0. RAID 1+0 is also called
striped mirror. The basic element of RAID 1+0 is a mirrored pair. This means that
data is first mirrored and then both copies of the data are striped across multiple
disk drive pairs in a RAID set.
Information Storage and Management (ISM) v4
Page 222
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
When replacing a failed drive, only the mirror is rebuilt. In other words, the storage
system controller uses the surviving drive in the mirrored pair for data recovery and
continuous operation. Data from the surviving disk is copied to the replacement
disk.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 223
RAID Techniques Lesson
RAID 3
Parity information is stored on a dedicated drive so that the data can be
reconstructed if a drive fails in a RAID set. For example, in a set of five disks, four
are used for data and one for parity.
Note: RAID 3 is not typically used in practice.
C
B
A
Data from compute
system
RAID Controller
A1
A2
A3
A4
Ap
Bp
B1
B2
B3
B4
C1
C2
C3
C4
Cp
Dedicated Parity Disk
Data Disks
Notes
In RAID 3, parity information is stored on a dedicated drive so that the data can be
reconstructed if a drive fails in a RAID set. For example, in a set of five disks, four
are used for data and one for parity.
Therefore, the total disk space that is required is 1.25 times the size of the data
disks. RAID 3 always reads and writes complete stripes of data across all disks
Information Storage and Management (ISM) v4
Page 224
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
because the drives operate in parallel. There are no partial writes that update one
out of many strips in a stripe.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 225
RAID Techniques Lesson
RAID 5
RAID 5 is a versatile RAID implementation. It is similar to RAID 4 because it uses
striping. The drives (strips) are also independently accessible.
C
B
A
Data from compute
system
RAID Controller
A1
A2
B1
C1
A3
A4
Ap
B2
B3
Bp
B4
C2
Cp
C3
C4
Distributed Parity
Notes
The difference between RAID 4 and RAID 5 is the parity location. In RAID 4, parity
is written to a dedicated drive, creating a write bottleneck for the parity disk.
In RAID 5, parity is distributed across all disks to overcome the write bottleneck of a
dedicated parity disk.
Information Storage and Management (ISM) v4
Page 226
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
RAID 6
RAID 6 works the same way as RAID 5, except that RAID 6 includes a second
parity element to enable survival if two disk failures occur in a RAID set. Therefore,
a RAID 6 implementation requires at least four disks.
C
B
A
Data from compute
system
RAID Controller
A1
A2
A3
Ap
Aq
B1
B2
Bp
Bq
B3
C1
Cp
Cq
C2
C3
Dual Distributed Parity
Notes
RAID 6 distributes the parity across all the disks. The write penalty (explained later
in this module) in RAID 6 is more than that in RAID 5; therefore, RAID 5 writes
perform better than RAID 6.
The rebuild operation in RAID 6 may take longer than that in RAID 5 due to the
presence of two parity sets.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 227
RAID Techniques Lesson
RAID Impacts on Performance

In RAID 5, every write (update) to a disk manifests as four I/O operations (2
reads and 2 writes)

In RAID 6, every write (update) to a disk manifests as six I/O operations (3
reads and 3 writes)

In RAID 1, every write manifests as two I/O operations (2 writes)
The figure illustrates a single write operation on RAID 5 that contains a group of
five disks.
Cp new
Cp old
C4 new
C4 old
RAID Controller
2
3
4
1
A1
A2
A3
A4
Ap
B1
B2
B3
Bp
B4
C1
C2
Cp
C3
C4
Notes
When choosing a RAID type, it is imperative to consider its impact on disk
performance and application IOPS. In both mirrored and parity RAID
configurations, every write operation translates into more I/O overhead for the
disks, which is referred to as a write penalty.
In a RAID 1 implementation, every write operation must be performed on two disks
configured as a mirrored pair, whereas in a RAID 5 implementation, a write
operation may manifest as four I/O operations. When performaing I/Os to a disk
configured with RAID 5, the controller has to read, recalculate, and write a parity
segment for every data write operation.
Information Storage and Management (ISM) v4
Page 228
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
The figure illustrates a single write operation on RAID 5 that contains a group of
five disks. The parity (P) at the controller is calculated as follows:
Cp = C1 + C2 + C3 + C4 (XOR operations)
Whenever the controller performs a write I/O, parity must be computed by reading
the old parity (Cp old) and the old data (C4 old) from the disk, which means two
read I/Os. Then, the new parity (Cp new) is computed as follows:
Cp new = Cp old – C4 old + C4 new (XOR operations)
After computing the new parity, the controller completes the write I/O by writing the
new data and the new parity onto the disks, amounting to two write I/Os. Therefore,
the controller performs two disk reads and two disk writes for every write operation,
and the write penalty is 4.
In RAID 6, which maintains dual parity, a disk write requires three read operations:
two parity and one data. After calculating both the new parities, the controller
performs three write operations: two parity and an I/O. Therefore, in a RAID 6
implementation, the controller performs six I/O operations for each write I/O, and
the write penalty is 6.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 229
RAID Techniques Lesson
RAID Comparison
RAID
Level
Minimum
Number of
Disks
Available
Storage
Capacity (%)
Write
Penalty
Protection
1
2
50
2
Mirror
1+0
4
50
2
Mirror
3
3
[(n-1)/n] * 100
4
Parity (Supports
single disk failure)
5
3
[(n-1)/n] * 100
4
Parity (Supports
single disk failure)
6
4
[(n-2)/n] * 100
6
Parity (Supports two
disk failures)
Information Storage and Management (ISM) v4
Page 230
© Copyright 2019 Dell Inc.
RAID Techniques Lesson
Dynamic Disk Sparing (Hot Sparing)
A hot sparing refers to a process that temporarily replaces a failed disk drive with a
spare drive in a RAID array by taking the identity of the failed disk drive.
With the hot spare, one of the following methods of data recovery is performed
depending on the RAID implementation:

If parity RAID is used, the data is rebuilt onto the hot spare from the parity and
the data on the surviving disk drives in the RAID set.

If mirroring is used, the data from the surviving mirror is used to copy the data
onto the hot spare.
Failed Disk
RAID
Controller
Replaced
Failed Disk
Hot Spare
Notes
When a new disk drive is added to the system, data from the hot spare is copied to
it. The hot spare returns to its idle state, ready to replace the next failed drive.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 231
RAID Techniques Lesson
Alternatively, the hot spare replaces the failed disk drive permanently. This means
that it is no longer a hot spare, and a new hot spare must be configured on the
storage system.
A hot spare should be large enough to accommodate data from a failed drive.
Some systems implement multiple hot spares to improve data availability.A hot
spare can be configured as automatic or user initiated, which specifies how it will
be used in the event of disk failure.
In an automatic configuration, when the recoverable error rates for a disk exceed a
predetermined threshold, the disk subsystem tries to copy data from the failing disk
to the hot spare automatically. If this task is completed before the damaged disk
fails, the subsystem switches to the hot spare and marks the failing disk as
unusable.
Otherwise, it uses parity or the mirrored disk to recover the data. In the case of a
user-initiated configuration, the administrator has control of the rebuild process. For
example, the rebuild could occur overnight to prevent any degradation of system
performance. However, the system is at risk of data loss if another disk failure
occurs.
Information Storage and Management (ISM) v4
Page 232
© Copyright 2019 Dell Inc.
Types of Intelligent Storage Systems Lesson
Types of Intelligent Storage Systems Lesson
Introduction
This lesson covers different types of data access methods. It also covers types of
intelligent storage systems. Finally, this lesson covers the scale-up and scale-out
architectures.
This lesson covers the following topics:

Explain data access methods

Describe types of intelligent storage systems

Compare scale-up and scale-out architectures
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 233
Types of Intelligent Storage Systems Lesson
Types of Intelligent Storage Systems
Video: Types of Intelligent Storage Systems
The video is located at
https://edutube.emc.com/Player.aspx?vno=QCuidmacmU3QZVzB5fsBvQ
Information Storage and Management (ISM) v4
Page 234
© Copyright 2019 Dell Inc.
Types of Intelligent Storage Systems Lesson
Types of Intelligent Storage Systems
Based on the type of data access, a storage system can be classified as :

Block-based

File-based

Object-based

Unified
A unified storage system provides block-based, file-based, and object-based data
access in a single system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 235
Types of Intelligent Storage Systems Lesson
Scale-up Vs. Scale-out Architecture
An intelligent storage system may be built either based on scale-up or scale-out
architecture:

Scale-up storage architecture provides the capability to scale the capacity and
performance of a single storage system based on requirements

Scale-out storage architecture provides the capability to maximize its capacity
by simply adding nodes to the cluster
Scale-out
Node 1
Storage
Controller(s)
Controller(s)
Node 2
Storage
Controller(s)
Node 3
Storage
Controller(s)
Scale-up
Cluster
Notes
Scaling up a storage system involves upgrading or adding controllers and storage.
These systems have a fixed capacity ceiling, which limits their scalability and the
performance also starts degrading when reaching the capacity limit.
In scale-out, nodes can be added quickly to the cluster, when more performance
and capacity is needed, without causing any downtime. This provides the flexibility
to use many nodes of moderate performance and availability characteristics to
produce a total system that has better aggregate performance and availability.
Scale-out architecture pools the resources in the cluster and distributes the
workload across all the nodes. This results in linear performance improvements as
more nodes are added to the cluster.
Information Storage and Management (ISM) v4
Page 236
© Copyright 2019 Dell Inc.
Types of Intelligent Storage Systems Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 237
Types of Intelligent Storage Systems Lesson
Assessment
1. Which one of the following is characteristic of RAID 5?
A. All parity in a single disk
B. Distributed parity
C. No parity
D. Double parity
2. What is the stripe size of a five disk parity RAID 5 set that has a strip size of 64
KB?
A. 256 KB
B. 64 KB
C. 128 KB
D. 320 KB
Information Storage and Management (ISM) v4
Page 238
© Copyright 2019 Dell Inc.
Summary
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 239
Block-Based Storage System
Introduction
This module focuses on the key components of a block-based storage system. It
details the function of each component, including cache management and
protection techniques. This module also focuses on the two storage provisioning
methods. Finally, this module focuses on the storage tiering mechanisms.
Upon completing this module, you will be able to:
 Describe the components of block-based storage system
 Describe traditional and virtual storage provisioning
 Describe storage tiering mechanisms
Information Storage and Management (ISM) v4
Page 240
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Components of a Block-Based Storage System Lesson
Introduction
This lesson covers block-based storage system components, intelligent cache
algorithms, and cache protection mechanisms.
This lesson covers the following topics:

Explain block-based storage system components

Describe intelligent cache algorithms

List cache protection mechanisms
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 241
Components of a Block-Based Storage System Lesson
Components of a Block-Based Storage System
Video: Components of a Block-Based Storage System
The video is located at
https://edutube.emc.com/Player.aspx?vno=Tqdv5ScTt8OHZXsSamWsoA
Information Storage and Management (ISM) v4
Page 242
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
What is a Block-Based Storage System?
A block-based storage system provides compute systems with block-level access
to the storage volumes. In this environment, the:

File system is created on the compute systems and data is accessed on a
network at the block level

Block-based storage systems can either be based on scale-up or scale-out
architecture

Block-based storage system consists of one or more controllers and storage
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 243
Components of a Block-Based Storage System Lesson
Components of a Controller

A controller of a block-based storage system consists of three key components:
 Front end, cache, and back end

An I/O request that is received from the compute system at the front-end port is
processed through cache and the back end
 Enables retrieval of data from the storage

A read request can be serviced directly from cache if the requested data is
found in the cache

In modern intelligent storage systems, front end, cache, and back end are
typically integrated on a single board
 Referred to as a storage processor or storage controller
Controller
Compute
Back End
Front End
VM
Storage
VM
Cache
Connectivity
Hypervisor
Storage Network
Information Storage and Management (ISM) v4
Page 244
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Component: Front End

The front end provides the interface between the storage system and the
compute system. It consists of two components:
 Front-end ports
 Front-end controllers
Controller
Compute
Front End
VM
Back End
Storage
VM
Cache
Connectivity
Hypervisor
Storage Network
Ports
Front-end Controllers
Notes
Typically, a front end has redundant controllers for high availability. Plus, each
controller contains multiple ports that enable large numbers of compute systems to
connect to the intelligent storage system.
Each front-end controller has processing logic that executes the appropriate
transport protocol, such as Fibre Channel, iSCSI, FICON, or FCoE for storage
connections. Front-end controllers route data to and from cache through the
internal data bus. When the cache receives the write data, the controller sends an
acknowledgment message back to the compute system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 245
Components of a Block-Based Storage System Lesson
Component: Cache
Cache is semiconductor memory where data is placed temporarily to reduce the
time that is required to service I/O requests from the compute system
Controller
Compute
VM
Back End
Front End
Storage
VM
Connectivity
Cache
Hypervisor
Storage
Network
Notes
Cache improves storage system performance by isolating compute systems from
the storage (HDDs and SSDs). In this case, cache improves storage system
performance by isolating compute systems from the mechanical delays that are
associated with rotating disks or HDDs.
Rotating disks are the slowest component of an intelligent storage system. Data
access on rotating disks usually takes several milliseconds because of seek time
and rotational latency. Accessing data from cache is fast and typically takes less
than a millisecond. On intelligent storage systems, write data is first placed in
cache and then written to the storage.
Information Storage and Management (ISM) v4
Page 246
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Read Operation with Cache
When a compute system issues a read request, the storage controller reads the tag
RAM to determine whether the required data is available in cache.

If the requested data is found in the cache, it is called a read cache hit or read
hit

If the requested data is not found in cache, it is called a cache miss
Data found in cache = Read Hit
VM
VM
Data found in cache
1. Read request
Hypervisor
Compute
2. Data sent to compute system
Storage
Data not found in cache = Read Miss
VM
VM
Data not found in cache
1. Read request
2. Read request
4. Data sent to
compute system
3. Data Copied to
cache
Hypervisor
Compute
Storage
Notes
When a compute system issues a read request, the storage controller reads the tag
RAM to determine whether the required data is available in cache. If the requested
data is found in the cache, it is called a read cache hit or read hit and data is sent
directly to the compute system, without any back-end storage operation. This
provides a fast response time to the compute system (about a millisecond).
If the requested data is not found in cache, it is called a cache miss and the data
must be read from the storage. The back end accesses the appropriate storage
device and retrieves the requested data. Data is then placed in cache and finally
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 247
Components of a Block-Based Storage System Lesson
sent to the compute system through the front end. Cache misses increase the I/O
response time.
Read performance is measured in terms of the read hit ratio, or the hit rate,
expressed as a percentage. This ratio is the number of read hits with respect to the
total number of read requests. A higher read hit ratio improves the read
performance.
Information Storage and Management (ISM) v4
Page 248
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Write Operation with Cache

Write operations with cache provide performance advantages over writing
directly to storage.

A write operation with cache is implemented in the following ways:
Write-through Cache
VM
VM
Cache
1. Data Write
2. Data Write
Hypervisor
4. Acknowledgement
Compute
3. Acknowledgement
Storage
Write-back Cache
VM
VM
Cache
1. Data Write
3. Data Write
Hypervisor
Compute
2. Acknowledgement
4. Acknowledgement
Storage
Notes
When an I/O is written to cache and acknowledged, it is completed in less time
(from the compute system’s perspective) than it would take to write directly to
storage. Sequential writes also offer opportunities for optimization because many
smaller writes can be coalesced for larger transfers to storage with the use of
cache.
A write operation with cache is implemented in the following ways:
Write-through cache
Data is placed in the cache and immediately written to the storage, and an
acknowledgment is sent to the compute system. Because data is committed to
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 249
Components of a Block-Based Storage System Lesson
storage as it arrives, the risks of data loss are low, but the write-response time is
longer because of the storage operations.
Write-back cache
Data is placed in cache and an acknowledgment is sent to the compute system
immediately. Later, data from several writes are committed (de-staged) to the
storage. Write response times are much faster because the write operations are
isolated from the storage devices. However, uncommitted data is at risk of loss if
cache failures occur.
For bypass, if the size of an I/O request exceeds the predefined size, called write
aside size, writes are sent directly to storage. This reduces the impact of large
writes consuming a large cache space. This is particularly useful in an environment
where cache resources are constrained and cache is required for small random
I/Os.
With dedicated cache, separate sets of memory locations are reserved for reads
and writes. In global cache, both reads and writes can use any of the available
memory addresses. Cache management is more efficient in a global cache
implementation because only one global set of addresses has to be managed.
Global cache enables users to specify the percentages of cache available for reads
and writes for cache management. Typically, the read cache is small, but it should
be increased if the application being used is read-intensive. In other global cache
implementations, the ratio of cache available for reads versus writes is dynamically
adjusted based on the workloads.
Information Storage and Management (ISM) v4
Page 250
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Cache Management: Algorithms
Pre-fetch

Used when read requests are sequential

Contiguous set of associated blocks is retrieved

Significantly improves the response time experienced by the compute system
Least recently used (LRU)

Discards data that has not been accessed for a long time
New Data
Cache
LRU Data
Notes
Cache is an expensive resource that needs proper management to improve
performance and to proactively maintain a set of free pages.
Even though modern intelligent storage systems come with a large amount of
cache, when all cache pages are filled, some pages have to be freed up to
accommodate new data and avoid performance degradation.
Various cache management algorithms are implemented in intelligent storage
systems to proactively maintain a set of free pages. A list of pages that can be
potentially freed up whenever required may also be maintained.
Least Recently Used (LRU): An algorithm that continuously monitors data access
in cache and identifies the cache pages that have not been accessed for a long
time. LRU either frees up these pages or marks them for reuse. This algorithm is
based on the assumption that data that has not been accessed for a while will not
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 251
Components of a Block-Based Storage System Lesson
be requested by the compute system. However, if a page contains write data that
has not yet been committed to storage, the data is first written to the storage before
the page is reused.
Prefetch: A prefetch or read-ahead algorithm is used when read requests are
sequential. In a sequential read request, a contiguous set of associated blocks is
retrieved. Several other blocks that have not yet been requested by the compute
system can be read from the storage and placed into cache in advance. When the
compute system subsequently requests these blocks, the read operations will be
read hits. This process significantly improves the response time experienced by the
compute system.
Information Storage and Management (ISM) v4
Page 252
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Cache Data Protection
Cache is volatile memory; so a power failure or any kind of cache failure will cause
loss of the data that is not yet committed to the storage drive. This risk of losing
uncommitted data that is held in cache can be mitigated using cache mirroring and
cache vaulting:
Cache mirroring
Each write to cache is held in two different memory locations on two independent
memory cards. If a cache failure occurs, the write data will still be safe in the
mirrored location and can be committed to the storage drive. Reads are staged
from the storage drive to the cache; therefore, if a cache failure occurs, the data
can still be accessed from the storage drives. Because only writes are mirrored,
this method results in better utilization of the available cache.
In cache mirroring approaches, the problem of maintaining cache coherency is
introduced. Cache coherency means that data in two different cache locations must
be identical at all times. It is the responsibility of the storage system's operating
environment to ensure coherency.
Cache vaulting
The risk of data loss due to power failure can be addressed in various ways:
powering the memory with a battery until the AC power is restored or using battery
power to write the cache content to the storage drives. If an extended power failure
occurs, using batteries is not a viable option. This is because in intelligent storage
systems, large amounts of data might need to be committed to numerous storage
drives, and batteries might not provide power for sufficient time to write each piece
of data to its intended storage drive.
Therefore, storage vendors use a set of physical storage drives to dump the
contents of cache during power failure. This is called cache vaulting and the
storage drives are called vault drives. When power is restored, data from these
storage drives is written back to write cache and then written to the intended drives.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 253
Components of a Block-Based Storage System Lesson
Component: Back End

Back end provides an interface between cache and the physical storage drives;
it consists of two components:
 Back-end ports
 Back-end controllers

Back-end controls data transfers between cache and the physical drives
 From cache, data is sent to the back end and then routed to the destination
storage drives
Controller
Compute
Front End
VM
Storage
Back End
VM
Cache
Connectivity
Hypervisor
Storage Network
Back-end Controllers
Ports
Notes
Physical drives are connected to ports on the back end. The back-end controller
communicates with the storage drives when performing reads and writes and also
provides additional, but limited, temporary data storage. The algorithms that are
implemented on back-end controllers provide error detection and correction, along
with RAID functionality.
For high data protection and high availability, storage systems are configured with
dual controllers with multiple ports. Such configurations provide an alternative path
to physical storage drives if a controller or port failure occurs. This reliability is
further enhanced if the storage drives are also dual-ported. In that case, each drive
port can connect to a separate controller. Multiple controllers also facilitate load
balancing.
Information Storage and Management (ISM) v4
Page 254
© Copyright 2019 Dell Inc.
Components of a Block-Based Storage System Lesson
Storage
Physical storage drives are connected to the back-end storage controller and
provide persistent data storage.
Controller
Compute
VM
Front End
Back End
VM
Connectivity
Hypervisor
Storage
Cache
Storage
Network
Notes
Modern intelligent storage systems provide support to a variety of storage drives
with different speeds and types, such as FC, SATA, SAS, and solid state drives.
They also support the use of a mix of SSD, FC, or SATA within the same storage
system.
Workloads that have predictable access patterns typically work well with a
combination of HDDs and SSDs. If the workload changes, or constant high
performance is required for all the storage being presented, using a SSD can meet
the desirable performance requirements.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 255
Storage Provisioning Lesson
Storage Provisioning Lesson
Introduction
This lesson covers traditional and virtual provisioning processes. This lesson also
covers LUN expansion and LUN masking mechanisms.
This lesson covers the following topics:

Explain traditional and virtual provisioning

Describe LUN expansion

List the importance of LUN masking
Information Storage and Management (ISM) v4
Page 256
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
Storage Provisioning
Video: Storage Provisioning
The video is located at
https://edutube.emc.com/Player.aspx?vno=UwaDbHyIxAL3UAgyyKt0yg
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 257
Storage Provisioning Lesson
Overview of Storage Provisioning
Definition: Storage Provisioning
The process of assigning storage resources to compute system
based on capacity, availability, and performance requirements.

Storage provisioning can be performed in two ways:
 Traditional
 Virtual

Virtual provisioning leverages virtualization technology for provisioning storage
for applications
Information Storage and Management (ISM) v4
Page 258
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
Logical Unit Number (LUN)
Definition: LUN
Each logical unit created from the RAID set is assigned a unique ID,
called a LUN. A LUN is also referred to as a volume, partition, or
device.

LUNs hide the organization and composition of the RAID set from the compute
systems

LUNs created by traditional storage provisioning methods are also referred to
as thick

Once allocated, a LUN appears to a host as an internal physical disk
Notes
RAID sets usually have a large capacity because they combine the total capacity of
individual drives in the set. Logical units are created from the RAID sets by
partitioning (seen as slices of the RAID set) the available capacity into smaller
units. These units are then assigned to the compute system based on their storage
requirements. Logical units are spread across all the physical drives that belong to
that set.
Each logical unit created from the RAID set is assigned a unique ID, called a logical
unit number (LUN). LUNs hide the organization and composition of the RAID set
from the compute systems. LUNs created by traditional storage provisioning
methods are also referred to as thick LUNs to distinguish them from the LUNs
created by virtual provisioning methods.
When a LUN is configured and assigned to a non-virtualized compute system, a
bus scan is required to identify the LUN. This LUN appears as a raw storage drive
to the operating system. To make this drive usable, it is formatted with a file system
and then the file system is mounted. In a virtualized compute system environment,
the LUN is assigned to the hypervisor, which recognizes it as a raw storage drive.
This drive is configured with the hypervisor file system, and then virtual storage
drives are created on it.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 259
Storage Provisioning Lesson
Virtual storage drives are files on the hypervisor file system. The virtual storage
drives are then assigned to virtual machines and appear as raw storage drive to
them. To make the virtual storage drive usable to the virtual machine, similar steps
are followed as in a non-virtualized environment. Here, the LUN space may be
shared and accessed simultaneously by multiple virtual machines.
Virtual machines can also access a LUN directly on the storage system. In this
method the entire LUN is allocated to a single virtual machine. Storing data in this
way is recommended when the applications running on the virtual machine are
response-time sensitive, and sharing storage with other virtual machines may
impact their response time. The direct access method is also used when a virtual
machine is clustered with a physical machine. In this case, the virtual machine is
required to access the LUN that is being accessed by the physical machine.
Information Storage and Management (ISM) v4
Page 260
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
Traditional Provisioning
In traditional storage provisioning, physical storage drives are logically grouped
together on which a required RAID level is applied to form a set, called RAID set.
The illustration shows a RAID set consisting of five storage drives that have been
sliced or partitioned into two LUNs: LUN 0 and LUN 1.These LUNs are then
assigned to Compute 1 and Compute 2 for their storage requirements.
Controller
LUN 0
Storage
Back End
Front End
Compute 1
(RAID Set)
Cache
LUN 0
Storage
Network
VM
VM
LUN 1
Compute 2
LUN 1
Notes
For traditional provisioning, the number of drives in the RAID set and the RAID
level determine the availability, capacity, and performance of the RAID set. It is
highly recommended to create the RAID set from drives of the same type, speed,
and capacity to ensure maximum usable capacity, reliability, and consistency in
performance.
For example, if drives of different capacities are mixed in a RAID set, the capacity
of the smallest drive is used from each drive in the set to make up the RAID set’s
overall capacity. The remaining capacity of the larger drives remains unused.
Likewise, mixing higher speed drives with lower speed drives lowers the overall
performance of the RAID set.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 261
Storage Provisioning Lesson
Virtual Provisioning

Virtual provisioning enables creating and presenting a LUN with more capacity
than is physically allocated to it on the storage system

The LUN created using virtual provisioning is called a thin LUN to distinguish it
from the traditional LUN

Thin LUNs do not require physical storage to be completely allocated to them at
the time they are created and presented to a compute system
10 TB
Thin
LUN 0
Compute System
Reported Capacity
Controller
3 TB
Allocated
Storage
Front End
Back End
Compute 1
Cache
(Storage Pool)
Thin
LUN 0
Storage
System
VM
VM
Thin
LUN 1
Hypervisor
10 TB
Compute 2
Thin
LUN 1
Compute System Reported
Capacity
4 TB
Allocated
Notes
Physical storage is allocated to the compute system “on-demand” from a shared
pool of physical capacity. A shared pool consists of physical storage drives. A
shared pool in virtual provisioning is analogous to a RAID set, which is a collection
of drives on which LUNs are created. Similar to a RAID set, a shared pool supports
a single RAID protection level. However, unlike a RAID set, a shared pool might
contain large numbers of drives. Shared pools can be homogeneous (containing a
single drive type) or heterogeneous (containing mixed drive types, such as SSD,
FC, SAS, and SATA drives).
Virtual provisioning enables more efficient allocation of storage to compute
systems. Virtual provisioning also enables oversubscription, where more capacity is
presented to the compute systems than is actually available on the storage system.
Both the shared pool and the thin LUN can be expanded non-disruptively as the
Information Storage and Management (ISM) v4
Page 262
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
storage requirements of the compute systems grow. Multiple shared pools can be
created within a storage system, and a shared pool may be shared by multiple thin
LUNs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 263
Storage Provisioning Lesson
Expand Thin LUNs and Storage Pool

A storage pool comprises physical drives that provide the physical storage that
is used by Thin LUNs
 A storage pool is created by specifying a set of drives and a RAID type for
that pool

Thin LUNs are then created out of that pool (similar to traditional LUN created
on a RAID set)
 All the Thin LUNs created from a pool share the storage resources of that
pool
 Adding drives to a storage pool increases the available shared capacity for
all the Thin LUNs in the pool

Drives can be added to a storage pool while the pool is used in production
 The allocated capacity is reclaimed by the pool when Thin LUNs are
destroyed
User
capacity
after
expansion
In-use
capacity
Thin LUN
Storage Pool
Storage Pool
Thin LUN
expansion
Adding storage drives to
the storage pool
Thin pool rebalancing
In-use
capacity
User
capacity
before
expansion
Thin LUN
Storage Pool Expansion
Thin LUN Expansion
When a storage pool is expanded, the sudden introduction of new empty drives
combined with relative full drives cause a data imbalance. This imbalance is
resolved by automating a one-time data relocation, referred to as rebalancing.
Storage pool rebalancing is a technique that provides the ability to automatically
relocate extents (minimum amount of physical storage capacity that is allocated to
the thin LUN from the pool) on physical storage drives over the entire pool when
new drives are added to the pool.
Information Storage and Management (ISM) v4
Page 264
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
Storage pool rebalancing restripes data across all the drives( both existing and new
drives) in the storage pool. This enables spreading out the data equally on all the
physical drives within the storage pool, ensuring that the used capacity of each
drive is uniform across the pool. After the storage pool capacity is increased, the
capacity of the existing LUNs can be expanded.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 265
Storage Provisioning Lesson
Traditional Provisioning vs. Virtual Provisioning

Administrators typically allocate storage capacity based on anticipated storage
requirements.
 This generally results in the over provisioning of storage capacity, which
then leads to higher costs and lower capacity utilization.

Administrators often over-provision storage to an application for various reasons
such as to:
 Avoid frequent provisioning of storage if the LUN capacity is exhausted
 Reduce disruption to application availability

Virtual provisioning:
 Addresses these challenges
 Improves storage capacity utilization and simplifies storage management
The illustration compares virtual provisioning with traditional storage provisioning.
150 GB Available
Capacity
800 GB
1500 GB or 1.5 TB
Allocated Unused
Capacity
400 GB
Allocated
Unused
Capacity
500 GB Allocated
Unused Capacity
550 GB
500 GB
600 GB
Allocated
Unused
Capacity
200 GB Allocated
100 GB Allocated
1650 GB or 1.65 TB
Available Capacity
350 GB Actual
Data
200 GB Allocated
100 GB Allocated
50 GB Allocated
Thin LUN 1
Thin LUN 2
350 GB Actual Data
50 GB Allocated
LUN 1 500 GB
LUN 2 550 GB
LUN 3 800 GB
Traditional Provisioning
Storage System 2 TB
Thin LUN 3
Storage System 2 TB
Virtual Provisioning
Information Storage and Management (ISM) v4
Page 266
© Copyright 2019 Dell Inc.
Storage Provisioning Lesson
Notes
With traditional provisioning, three LUNs are created and presented to one or more
compute systems. The total storage capacity of the storage system is 2 TB. The
allocated capacity of LUN 1 is 500 GB, of which only 100 GB is consumed, and the
remaining 400 GB is unused. The size of LUN 2 is 550 GB, of which 50 GB is
consumed, and 500 GB is unused. The size of LUN 3 is 800 GB, of which 200 GB
is consumed, and 600 GB is unused.
In total, the storage system has 350 GB of data, 1.5 TB of allocated but unused
capacity, and only 150 GB of remaining capacity available for other applications.
Now consider the same 2 TB storage system with virtual provisioning. Here, three
thin LUNs of the same sizes are created. However, there is no allocated unused
capacity. In total, the storage system with virtual provisioning has the same 350 GB
of data, but 1.65 TB of capacity is available for other applications, whereas only
150 GB is available in traditional storage provisioning.
Virtual provisioning and thin LUN offer many benefits, although in some cases
traditional LUN is better suited for an application. Thin LUNs are appropriate for
applications that can tolerate performance variations. In some cases, performance
improvement is perceived when using a thin LUN, due to striping across a large
number of drives in the pool. However, when multiple thin LUNs contend for shared
storage resources in a given pool, and when utilization reaches higher levels, the
performance can degrade. Thin LUNs provide the best storage space efficiency
and are suitable for applications where space consumption is difficult to forecast.
Using thin LUNs benefits organizations in reducing power and acquisition costs and
in simplifying their storage management.
Traditional LUNs are suited for applications that require predictable performance.
Traditional LUNs provide full control for precise data placement and allow an
administrator to create LUNs on different RAID groups if there is any workload
contention. Organizations that are not highly concerned about storage space
efficiency may still use traditional LUNs. Both traditional and thin LUNs can coexist
in the same storage system. Based on the requirement, an administrator may
migrate data between thin and traditional LUNs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 267
Storage Provisioning Lesson
LUN Masking
Definition: LUN Masking
A process that provides data access control by defining which LUNs a
compute system can access.

Implemented on a storage system

Prevents unauthorized or accidental use of LUNs in a shared environment
Notes
The LUN masking function is implemented on the storage system. This ensures
that volume access by a compute system is controlled appropriately, preventing
unauthorized, or accidental use in a shared environment.
For example, consider a storage system with two LUNs that store data of the sales
and finance departments. Without LUN masking, both departments can easily see
and modify each other’s data, posing a high risk to data integrity and security. With
LUN masking, LUNs are accessible only to the designated compute systems.
Information Storage and Management (ISM) v4
Page 268
© Copyright 2019 Dell Inc.
Storage Tiering Lesson
Storage Tiering Lesson
Introduction
This lesson covers FAST VP and cache tiering.
This lesson covers the following topics:

Explain Fully Automated Storage Tiering for Virtual Provisioning (FAST VP)

Discuss Cache tiering
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 269
Storage Tiering Lesson
Storage Tiering
Video: Storage Tiering
The video is located at
https://edutube.emc.com/Player.aspx?vno=lH431R/R5rQM6ICC5+VYFQ
Information Storage and Management (ISM) v4
Page 270
© Copyright 2019 Dell Inc.
Storage Tiering Lesson
Storage Tiering Overview
Definition: Storage Tiering
A technique of establishing a hierarchy of storage types and
identifying the candidate data to relocate to the appropriate storage
type to meet service level requirements at a minimal cost.

Definition: Storage Tiering
– A technique of establishing a hierarchy of storage types and identifying the
candidate data to relocate to the appropriate storage type to meet service
level requirements at a minimal cost

Each tier has different levels of protection, performance, and cost

Efficient storage tiering requires defining tiering policies

Tiering options in block-based storage systems are: FAST VP and Cache tiering
Notes
Storage tiering is a technique of establishing a hierarchy of different storage types
(tiers). This enables storing the right data to the right tier, based on service level
requirements, at a minimal cost. Each tier has different levels of protection,
performance, and cost. For example, high performance solid-state drives (SSDs) or
FC drives can be configured as tier 1 storage to keep frequently accessed data and
low cost SATA drives as tier 2 storage to keep the less frequently accessed data.
Keeping frequently used data in SSD or FC improves application performance.
Moving less-frequently accessed data to SATA can free up storage capacity in high
performance drives and reduce the cost of storage. This movement of data
happens based on defined tiering policies. The tiering policy might be based on
parameters, such as frequency of access.
For example, if a policy states “move the data that are not accessed for the last 30
mins to the lower tier,” then all the data matching this condition are moved to the
lower tier.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 271
Storage Tiering Lesson
The process of moving the data from one type of tier to another is typically
automated. In automated storage tiering, the application workload is proactively
monitored; the active data is automatically moved to a higher performance tier and
the inactive data is moved to higher capacity, lower performance tier. The data
movement between the tiers is performed non-disruptively.
The techniques of storage tiering implemented in a block-based storage system
are: FAST VP and cache tiering.
Information Storage and Management (ISM) v4
Page 272
© Copyright 2019 Dell Inc.
Storage Tiering Lesson
LUN and Sub-LUN (FAST VP) Tiering
The process of
storage tiering
within a storage
system is called
intra-array storage
tiering. It enables
the efficient use of
SSD, FC, and
SATA drives within
a system and
provides
performance and
cost optimization.
Tier 0
LUN
LUN
Move entire LUN
with active data
from tier 1 to tier 0
for improved
performance
Move entire LUN with
inactive data from tier 0 to
tier 1
Tier 1
LUN
LUN
LUN Tiering
Tier 0
Move active data from
tier 1 to tier 0 for
improved performance
Move inactive data from
tier 0 to tier 1
The goal is to
keep the SSDs
Tier 1
busy by storing the
Sub-LUN Tiering
most frequently
accessed data on
Inactive Data
them, while
Active Data
moving out the
less frequently
accessed data to
the SATA drives.
Data movements that are executed between tiers can be performed at the LUN
level or at the sub-LUN level. The performance can be further improved by
implementing tiered cache.
LUN tiering
Sub-LUN Tiering

Moves entire LUN from one tier to
another.

A LUN is broken down into smaller
segments and tiered at that level.

Does not give effective cost and
performance benefits.

Provides effective cost and
performance benefits
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 273
Storage Tiering Lesson
Notes
Traditionally, storage tiering is operated at the LUN level that moves an entire LUN
from one tier of storage to another. This movement includes both active and
inactive data in that LUN. This method does not give effective cost and
performance benefits.
Today, storage tiering can be implemented at the sub-LUN level. In sub-LUN level
tiering, a LUN is broken down into smaller segments and tiered at that level.
Movement of data with much finer granularity, for example 8 MB, greatly enhances
the value proposition of automated storage tiering. Tiering at the sub-LUN level
effectively moves active data to faster drives and less active data to slower drives.
Information Storage and Management (ISM) v4
Page 274
© Copyright 2019 Dell Inc.
Storage Tiering Lesson
Cache Tiering
DRAM Cache
Tier 0
Tier 1
SSD
Tiered Cache
Storage System

Enables creation of a large capacity secondary cache using SSDs

Enables tiering between DRAM cache and SSDs (secondary cache)

Most reads are served directly from high performance tiered cache

Enhances performance during peak workloads

Non-disruptive and transparent to applications
Notes
Tiering is also implemented at the cache level. A large cache in a storage system
improves performance by retaining large amount of frequently accessed data in a
cache; so most reads are served directly from the cache. However, configuring a
large cache in the storage system involves more cost.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 275
Storage Tiering Lesson
An alternative way to increase the size of the cache is by utilizing the SSDs on the
storage system. In cache tiering, SSDs are used to create a large capacity
secondary cache and to enable tiering between DRAM (primary cache) and SSDs
(secondary cache).
Server flash-caching is another tier of cache in which flash-cache card is installed
in the server to further enhance the application performance.
Information Storage and Management (ISM) v4
Page 276
© Copyright 2019 Dell Inc.
Storage Tiering Lesson
Use Case - Block-Based Storage in a Cloud
Storage as a Service
VM instances running business
applications
To gain cost advantage,
organizations may move their
application to a cloud. To
ensure proper functioning of
the application and provide
acceptable performance,
service providers offer blockbased storage in cloud.
The service providers enable
the consumers to create
block-based storage volumes
and attach them to the virtual
machine instances. After the
volumes are attached,
consumers can create the file
system on these volumes
and run applications the way
they would on an on-premise
data center.
VM
VM
VM
APP
APP
APP
OS
OS
OS
Block-based
storage volumes
Block-based storage
system
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 277
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC XtremIO

Dell EMC FAST VP

Dell EMC PowerMax

Dell EMC SC Series
Information Storage and Management (ISM) v4
Page 278
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
Dell EMC XtremIO
DellEMC XtremIO is an all-flash, block-based, scale-out enterprise storage system
that provides substantial improvements to I/O performance. It is purpose-built to
leverage flash media and delivers new levels of real-world performance,
administrative ease, and advanced data services for applications. It uses a scaleout clustered design that grows capacity and performance linearly to meet any
requirement.
XtremIO storage systems are created from building blocks called "X-Bricks" that
are each a high-availability, high-performance, fully active/active storage system
with no single point of failure. XtremIO's powerful operating system, XIOS,
manages the XtremIO storage cluster. XIOS ensures that the system remains
balanced and always delivers the highest levels of performance with no
administrator intervention.
XtremIO helps the administrators to become more efficient by enabling system
configuration in a few clicks, provisioning storage in seconds, and monitoring the
environment with real-time metrics.
Dell EMC FAST VP
Performs storage tiering at a sub-LUN level in a virtual provisioned environment.
FAST VP automatically moves more active data (data that is more frequently
accessed) to the best performing storage tier, and it moves less active data to a
lower performance and less expensive tier.
Data movement between the tiers is based on user-defined policies, and is
executed automatically and non-disruptively by FAST VP.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 279
Concepts in Practice Lesson
Dell EMC PowerMax
DellEMC PowerMax is the fast storage array delivering unprecedented levels of
performance with up to 10M IOPS, 150 GB per second of sustained bandwidth.
The key to unlocking the next level of performance is NVMe, which removes the
bottleneck form storage (SAS), which maximizes the power of flash drives, and
most importantly opens the door to the next media disruption with storage class
memory (SCM).
PowerMax will deliver up to 25% better response times with NVMe Flash drives.
The combination of NVMe and SCM will unlock even greater performance reaching
up to 50% better response times.
The array offers flexible scale-up and scale-out architecture. Configuration
management is simple with Unisphere for PowerMax. The intuitive HTML5 GUI
provides a simple and feature-rich user experience.
The easiest way to describe CloudIQ is that it is like a fitness tracker for your
storage environment, providing a single, simple, display to monitor and predict the
health of your storage environment. CloudIQ makes it simple to track storage
health, report on historical trends, plan for future growth, and proactively discover
and remediate issues from any browser or mobile device.
Dell EMC SC Series
SC offers two categories of arrays SC Hybrid(SSD & HDD) and SC All-Flash. SC
Series was one of the original pioneers of auto-tiering – and have the most fullfeatured, powerful implementation, helping you get great flash performance with
less hardware, and a less expensive mix of hardware. SC arrays also provision
RAID dynamically to help cut costs and increase performance.
In addition to leading platform efficiency (auto-tiering, RAID tiering, thin methods),
SC arrays also offer the most comprehensive data reduction with Intelligent
Deduplication and Compression on:

SSDs in all-flash configurations

SSDs and HDDs in hybrid configurations
SC Series provides users with advanced thin provisioning technologies that
optimize storage utilization within their environments. Unlike traditional SANs,
Information Storage and Management (ISM) v4
Page 280
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Storage Center does not require users to pre-allocate space. Storage is pooled,
ensuring space is available when and where it is needed. You can even reclaim
capacity that is no longer in use by applications, automatically reduce the space
needed for virtual OS volumes and thin import volumes on legacy storage to
improve capacity utilization.
SC Series Remote Instant Replay software efficiently replicates periodic snapshots
between local and remote sites, helping to ensure business continuity at a fraction
of the cost of other replication solutions.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 281
Concepts in Practice Lesson
Assessment
1. The process of storage tiering within a storage system is called ?
A. Intra-array storage tiering
B. Inter-array storage tiering
C. LUN tiering
D. Sub-LUN tiering
2. Which is a process that provides data access control by defining which LUNs a
compute system can access?
A. LUN masking
B. Tiering
C. Virtual provisioning
D. Thin LUN
Information Storage and Management (ISM) v4
Page 282
© Copyright 2019 Dell Inc.
Summary
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 283
Fibre Channel SAN
Introduction
This module presents an overview of Fibre Channel Storage Area Network (FC
SAN), its components and architecture. It also focuses on FC SAN topologies, and
zoning along with describing virtualization process in FC SAN environment.
Upon completing this module, you will be able to:




Describe Fibre Channel (FC) SAN and its components
Describe FC architecture
Describe FC SAN topologies and zoning
Describe a Virtual SAN (VSAN)
Information Storage and Management (ISM) v4
Page 284
© Copyright 2019 Dell Inc.
Introduction to SAN Lesson
Introduction to SAN Lesson
Introduction
This lesson presents definition of SAN and its benefits and requirements.
This lesson covers the following topics:

Definition of SAN

Benefits of SAN

Requirements for a SAN
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 285
Introduction to SAN Lesson
Introduction to SAN
Storage Area Network (SAN) Overview
Definition: SAN
A network whose primary purpose is the transfer of data between
computer systems and storage devices and among storage devices.
Source: Storage Networking Industry Association
Storage Area Network (SAN) is a network that primarily connects the storage
systems with the compute systems and also connects the storage systems with
each other. It enables multiple compute systems to access and share storage
resources. It also enables to transfer data between the storage systems. With longdistance SAN, the data transfer over SAN can be extended across geographic
locations. A SAN usually provides access to block-based storage systems.
Data Center 1
Data Center 2
Client
Client
VM
AP
P
V
M
AP
P
O
S
O
S
O
S
VM
NAS
V
M
AP
P
AP
P
Hypervisor
Compute
System
LAN
WAN
LAN
NAS
O
S
Hypervisor
Compute
System
Clients
SAN
SAN
Storage Systems
Storage Systems
Information Storage and Management (ISM) v4
Page 286
© Copyright 2019 Dell Inc.
Introduction to SAN Lesson
Benefits of SAN

Enables both consolidation and sharing of storage resources across multiple
compute systems
 Improves utilization of storage resources
 Centralizes management

Enables connectivity across geographically dispersed locations
 Enables compute systems across locations to access shared data
 Enables replication of data between storage systems that reside in separate
locations
 Facilitates remote backup of application data
Notes
SAN addresses the limitations of Direct-Attached Storage (DAS) environment.
Unlike a DAS environment, where the compute systems own the storage, SANs
enable both consolidation and sharing of storage resources across multiple
compute systems. This process improves the utilization of storage resources
compared to a DAS environment. It also reduces the total amount of storage that
an organization needs to purchase and manage. With consolidation, storage
management becomes centralized and less complex, which further reduces the
cost of managing information. A SAN may span over wide locations. This flexibility
enables organizations to connect geographically dispersed compute systems and
storage systems. The long-distance SAN connectivity enables the compute
systems across locations to access shared data. The long-distance connectivity
also enables the replication of data between storage systems that reside in
separate locations. The replication over long-distances helps in protecting data
against local and regional disaster. Further, the long-distance SAN connectivity
facilitates remote backup of application data. Backup data can be transferred
through a SAN to a backup device that may reside at a remote location. This
feature avoids having to ship tapes (backup media) from the primary site to the
remote site. Also avoids associated pitfalls such as packing and shipping expenses
and lost tapes in transit.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 287
Introduction to SAN Lesson
Requirements for a SAN
An effective SAN infrastructure must provide:

High throughput to support high-performance computing

Interconnectivity among many devices over wide locations to transfer massively
distributed, high volume of data

Elastic and non-disruptive scaling to support applications that are horizontally
scaled

Automated and policy-driven infrastructure configuration

Simplified, flexible, and agile management operations
Information Storage and Management (ISM) v4
Page 288
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
FC SAN Overview Lesson
Introduction
This lesson presents the components of FC SAN, three FC interconnectivity
options, and FC port types.
This lesson covers the following topics:

Components of FC SAN

FC interconnectivity options

FC port types
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 289
FC SAN Overview Lesson
FC SAN Overview
Video: FC SAN Overview
The video is located at
https://edutube.emc.com/Player.aspx?vno=iU0awg65X0P0YpgkPgH5Lw
Information Storage and Management (ISM) v4
Page 290
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
FC SAN Overview
Hypervisor
Hypervisor
Hypervisor
Compute Systems
FC SAN
Storage Systems

A SAN that uses FC protocol for communication

A high-speed network that runs on high-speed optical fiber cables and serial
copper cables

FC speeds commonly run at 1, 2, 4, 8, 16, 32, and 128 Gb/s

Provides high scalability
Notes
Fibre Channel SAN (FC SAN) uses Fibre Channel (FC) protocol for
communication. FC protocol (FCP) is used to transport data, commands, and
status information between the compute systems and the storage systems. It is
also used to transfer data between the storage systems. FC is a high-speed
network technology that runs on high-speed optical fiber cables and serial copper
cables. The FC technology was developed to meet the demand for the increased
speed of data transfer between compute systems and mass storage systems. In
comparison with Ultra-Small Computer System Interface (Ultra-SCSI) that is
commonly used in the DAS environments, FC is a significant leap in storage
networking technology. Note: FibRE refers to the protocol, whereas fibER refers to
a media.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 291
FC SAN Overview Lesson
Information Storage and Management (ISM) v4
Page 292
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
Components of FC SAN
The key FC SAN components
are network adapters, cables,
and interconnecting devices.
These components are
described in the following:

Light In
Network adapters
 FC HBAs in compute
system
Multimode Fibre
 Front-end adapters in
storage system

Core
Cladding
Cladding
Core
Cables
 Copper cables for short
distance
Light In
 Optical fiber cables for
long distance
 Two types:
Single-mode Fibre
o Multimode
o Single-mode

Interconnecting devices
 FC hubs, FC switches, and FC directors
Notes
Network Adapters
In an FC SAN, the end devices, such as compute systems and storage systems
are all referred to as nodes. Each node is a source or destination of information.
Each node requires one or more network adapters to provide a physical interface
for communicating with other nodes. Examples of network adapters are FC host
bus adapters (HBAs) and storage system front-end adapters. An FC HBA has
SCSI-to-FC processing capability. It encapsulates operating system or hypervisor
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 293
FC SAN Overview Lesson
storage I/Os (usually SCSI I/O) into FC frames before sending the frames to the FC
storage systems over an FC SAN.
Cables
FC SAN implementations primarily use optical fiber cabling. Copper cables may be
used for shorter distances because it provides acceptable signal-to-noise ratio for
distances up to 30 meters. Optical fiber cables carry data in the form of light. There
are two types of optical cables: multimode and single-mode. Multimode fiber (MMF)
cable carries multiple beams of light that is projected at different angles
simultaneously onto the core of the cable. In an MMF transmission, multiple light
beams traveling inside the cable tend to disperse and collide. This collision
weakens the signal strength after it travels a certain distance – a process that is
known as modal dispersion. Due to modal dispersion, an MMF cable is typically
used for short distances, commonly within a data center.
Single-mode fiber (SMF) carries a single ray of light that is projected at the center
of the core. The small core and the single light wave help to limit modal dispersion.
Single-mode provides minimum signal attenuation over maximum distance (up to
10 km). A single-mode cable is used for long-distance cable runs, and the distance
usually depends on the power of the laser at the transmitter and the sensitivity of
the receiver. A connector is attached at the end of a cable to enable swift
connection and disconnection of the cable to and from a port. A standard connector
(SC) and a lucent connector (LC) are two commonly used connectors for fiber optic
cables.
Interconnecting Devices
The commonly used interconnecting devices in FC SANs are FC hubs, FC
switches, and FC directors.
Information Storage and Management (ISM) v4
Page 294
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
FC Interconnecting Devices
FC Hub
FC Switch
FC Director

Nodes are
connected in a
logical loop

Each node has a
dedicated communication
path

High-end switches
with a higher port
count

Nodes share loop



Provides limited
connectivity and
scalability
Provides a fixed port
count ─ active or unused
Has a modular
architecture

Active ports can be

scaled-up non-disruptively

Some components are
redundant and hotswappable

Port count is scaledup by inserting line
cards/blades
All key components
are redundant and
hot-swappable
Notes
FC hubs are used as communication devices in Fibre Channel Arbitrated Loop
(FC-AL) implementations (discussed later). Hubs physically connect nodes in a
logical loop or a physical star topology. All the nodes must share the loop because
data travels through all the connection points. Because of the availability of lowcost and high-performance switches, the FC switches are preferred over the FC
hubs in FC SAN deployments.
FC switches are more intelligent than FC hubs and directly route data from one
physical port to another. Therefore, the nodes do not share the data path. Instead,
each node has a dedicated communication path. The FC switches are commonly
available with a fixed port count. Some of the ports can be active for operational
purpose and the rest remain unused. The number of active ports can be scaled-up
non-disruptively. Some of the components of a switch such as power supplies and
fans are redundant and hot-swappable. Hot-swappable means components can be
replaced while a device is powered-on and remains in operation.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 295
FC SAN Overview Lesson
FC directors are high-end switches with a higher port count. A director has a
modular architecture and its port count is scaled-up by inserting extra line cards or
blades to the director’s chassis. Directors contain redundant components with
automated failover capability. Its key components such as switch controllers,
blades, power supplies, and fan modules are all hot-swappable. These ensure high
availability for business critical applications.
Information Storage and Management (ISM) v4
Page 296
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
FC Interconnecting Options
The FC architecture supports three basic interconnectivity options: point-to-point,
fibre channel arbitrated loop (FC-AL), and fibre channel switched fabric (FC-SW).
These interconnectivity options are described in the following:
Point-to-Point
In this configuration, two nodes are connected directly to each other. This
configuration provides a dedicated connection for data transmission between
nodes. However, the point-to-point configuration offers limited connectivity and
scalability and is used in a DAS environment.
VM
VM
Hypervisor
Compute System
Storage System
FC Arbitrated Loop (FC-AL)
In this configuration, the devices are attached to a shared loop. Each device
contends with other devices to perform I/O operations. The devices on the loop
must “arbitrate” to gain control of the loop. At any given time, only one device can
perform I/O operations on the loop. Because each device in a loop must wait for its
turn to process an I/O request, the overall performance in FC-AL environments is
low.
Further, adding or removing a device results in loop re-initialization, which can
cause a momentary pause in loop traffic. As a loop configuration, FC-AL can be
implemented without any interconnecting devices by directly connecting one device
to another two devices in a ring through cables. However, FC-AL implementations
may also use FC hubs through which the arbitrated loop is physically connected in
a star topology.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 297
FC SAN Overview Lesson
VM
VM
Compute
Systems
Hypervisor
VM
VM
Compute
Systems
FC Hub
Hypervisor
Compute System
Storage System
FC Switched Fabric (FC-SW)
It includes a single FC switch or a network of FC switches (including FC directors)
to interconnect the nodes. It is also referred to as fabric connect. A fabric is a
logical space in which all nodes communicate with one another in a network. In a
fabric, the link between any two switches is called an interswitch link (ISL). ISLs
enable switches to be connected together to form a single, larger fabric. They
enable the transfer of both storage traffic and fabric management traffic from one
switch to another.
In FC-SW, nodes do not share a loop. Instead, data is transferred through a
dedicated path between the nodes. Unlike a loop configuration, an FC-SW
configuration provides high scalability. The addition or removal of a node in a
switched fabric is minimally disruptive. It does not affect the ongoing traffic between
other nodes.
VM
VM
Hypervisor
FC Switch
FC Switch
Compute System
Interswitch Link
Compute System
Storage System
Information Storage and Management (ISM) v4
Page 298
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
Port Types in Switched Fabric
Port
Description
N_Port
An end point in the fabric. This port is also known as the node port.
Typically, it is a compute system port (FC HBA port) or a storage system
port that is connected to a switch in a switched fabric.
E_Port
A port that forms the connection between two FC switches. This port is
also known as the expansion port. The E_Port on an FC switch
connects to the E_Port of another FC switch in the fabric ISLs.
F_Port
A port on a switch that connects an N_Port. It is also known as a fabric
port.
G_Port
A generic port on a switch that can operate as an E_Port or an F_Port
and determines its functionality automatically during initialization.
VM
VM
N_Port
Hypervisor
Compute System
F_Port
FC Switch
FC Switch
F_Port
E_Port
E_Port
F_Port
ISL
N_Port
N_Port
Storage System
Storage System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 299
FC SAN Overview Lesson
NVMe over Fibre Channel

Organizations are adopting NVMe protocol to access SSDs over the PCIe bus

NVMe over FC is designed to transfer NVMe-based data over a FC network

Reduces latency and improves the performance of SSDs

FC protocol maps NVMe (upper layer protocol) to the lower layers for the data
transfer
Information Storage and Management (ISM) v4
Page 300
© Copyright 2019 Dell Inc.
FC SAN Overview Lesson
Definition: SAN
A network whose primary purpose is the transfer of data between
computer systems and storage devices and among storage devices.
Source: Storage Networking Industry Association
Storage Area Network (SAN) is a network that primarily connects the storage
systems with the compute systems and also connects the storage systems with
each other. It enables multiple compute systems to access and share storage
resources. It also enables to transfer data between the storage systems. With longdistance SAN, the data transfer over SAN can be extended across geographic
locations. A SAN usually provides access to block-based storage systems.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 301
FC Architecture Lesson
FC Architecture Lesson
Introduction
This lesson presents FC protocol stack, FC addressing, the structure and
organization of FC data, and fabric login types.
This lesson covers the following topics:

FC protocol stack

FC addressing

Structure and organization of FC data

Fabric login types
Information Storage and Management (ISM) v4
Page 302
© Copyright 2019 Dell Inc.
FC Architecture Lesson
FC SAN Architecture
Video: Fibre Channel Architecture
The video is located at
https://edutube.emc.com/Player.aspx?vno=t9/lhF5Hze0I9ybdsceHpg
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 303
FC Architecture Lesson
FC Architecture Overview

Provides benefits of both channel and network technologies
 Provides high performance with low protocol overheads
 Provides high scalability with long-distance capability

Implements SCSI over FC network
 Transports SCSI data through FC network

Storage devices, attached to FC SAN, appear as locally attached to the
operating system or hypervisor
Notes
Traditionally, compute operating systems have communicated with peripheral
devices over channel connections, such as Enterprise Systems Connection
(ESCON) and SCSI. Channel technologies provide high levels of performance with
low protocol overheads. Such performance is achievable due to the static nature of
channels and the high level of hardware and software integration that is provided
by the channel technologies. However, these technologies suffer from inherent
limitations in terms of the number of devices that can be connected and the
distance between these devices.
In contrast to channel technology, network technologies are more flexible and
provide greater distance capabilities. Network connectivity provides greater
scalability and uses shared bandwidth for communication. This flexibility results in
greater protocol overhead and reduced performance.
The FC architecture represents true channel and network integration and captures
some of the benefits of both channel and network technology. FC protocol provides
both the channel speed for data transfer with low protocol overhead and the
scalability of network technology. FC provides a serial data transfer interface that
operates over copper wire and optical fiber.
FC protocol forms the fundamental construct of the FC SAN infrastructure. FC
protocol predominantly is the implementation of SCSI over an FC network. SCSI
data is encapsulated and transported within FC frames. SCSI over FC overcomes
the distance and the scalability limitations that are associated with traditional directattached storage. Storage devices attached to the FC SAN appear as locally
Information Storage and Management (ISM) v4
Page 304
© Copyright 2019 Dell Inc.
FC Architecture Lesson
attached devices to the operating system (OS) or hypervisor running on the
compute system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 305
FC Architecture Lesson
FC Protocol Stack
It is easier to understand a communication protocol by viewing it as a structure of
independent layers. FCP defines the communication protocol in five layers: FC-0
through FC-4 (except FC-3 layer, which is not implemented).
Upper Layer Protocol
HIPPI, ESCON, ATM, IP
FC-4
Examples: SCSI,
Upper Layer Protocol Mapping
Framing/ flow Control
FC-2
Encode/Decode
FC-1
1 Gb/s
FC-0
2 Gb/s
4 Gb/s
8 Gb/s
16 Gb/s
Listed is a breakdown of each layer with its function and features.
FC
Function
Layer
Features Specified by FC Layer
FC-4
Mapping
interface
Mapping upper layer protocol (for example SCSI) to lower
FC layers
FC-3
Common
services
Not implemented
FC-2
Routing, flow
control
Frame structure, FC addressing, flow control
FC-1
Encode/decode 8b/10b or 64b/66b encoding, bit, and frame
synchronization
FC-0
Physical layer
Media, cables, connector
Information Storage and Management (ISM) v4
Page 306
© Copyright 2019 Dell Inc.
FC Architecture Lesson
Notes
FC-4 Layer: It is the uppermost layer in the FCP stack. This layer defines the
application interfaces and the way Upper Layer Protocols (ULPs) are mapped to
the lower FC layers. The FC standard defines several protocols that can operate on
the FC-4 layer. Some of the protocols include SCSI, High Performance Parallel
Interface (HIPPI) Framing Protocol, ESCON, Asynchronous Transfer Mode (ATM),
and IP.
FC-2 Layer: It provides FC addressing, structure, and organization of data (frames,
sequences, and exchanges). It also defines fabric services, classes of service, flow
control, and routing.
FC-1 Layer: It defines how data is encoded prior to transmission and decoded
upon receipt. At the transmitter node, an 8-bit character is encoded into a 10-bit
transmission character. This character is then transmitted to the receiver node. At
the receiver node, the 10-bit character is passed to the FC-1 layer, which decodes
the 10-bit character into the original 8-bit character. FC links, with a speed of 10
Gbps and above, use 64-bit to 66-bit encoding algorithm. This layer also defines
the transmission words such as FC frame delimiters, which identify the start and
the end of a frame and the primitive signals that indicate events at a transmitting
port. In addition to these, the FC-1 layer performs link initialization and error
recovery.
FC-0 Layer: It is the lowest layer in the FCP stack. This layer defines the physical
interface, media, and transmission of bits. The FC-0 specification includes cables,
connectors, and optical and electrical parameters for various data rates. The FC
transmission can use both electrical and optical media.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 307
FC Architecture Lesson
FC Addressing in Switched Fabric

FC address is assigned to node ports during fabric login
 Used for communication between nodes in an FC SAN

FC address size is 24 bits:
Domain ID
Bits (23 -26)

Area ID
Bits (15-08)
Port ID
Bits (07 - 00)
Main purpose of an FC address is routing data through the fabric
Notes
An FC address is dynamically assigned when a node port logs on to the fabric. The
FC address has a distinct format, as shown on the image. The first field of the FC
address contains the domain ID of the switch. A domain ID is a unique number that
is provided to each switch in the fabric. The area ID is used to identify a group of
switch ports that are used for connecting nodes.
An example of a group of ports with common area ID is a port card on the switch.
The last field, the port ID, identifies the port within the group. The FC address size
is 24 bits. The primary purpose of an FC address is routing data through the fabric.
Information Storage and Management (ISM) v4
Page 308
© Copyright 2019 Dell Inc.
FC Architecture Lesson
World Wide Name

Unique 64-bit identifier

Static to node ports on an FC network
 Similar to MAC address of NIC
 WWNN and WWPN are used to physically identify FC network adapters and
node ports respectively
World Wide Name - Array
5
0
0
0101
0000
0000
Format
Type
6
0110
0
0000
1
0001
6
0
0
0110
0000
0000
Company ID
24 bits
0
0000
6
0
0
1
B
2
0110
0000
0000
0001
1011
0010
c
4
0
Model Seed
32 bits
Port
World Wide Name - HBA
1
Format
Type
0
0
0
Reserved
12 bits
0
0
0
0
c
9
2
Company ID
24 bits
0
d
Company Specific 24
bits
Notes
Each device in the FC environment is assigned a 64-bit unique identifier that is
called the World Wide Name (WWN). The FC environment uses two types of
WWNs: World Wide Node Name (WWNN) and World Wide Port Name (WWPN).
WWNN is used to physically identify FC network adapters, and WWPN is used to
physically identify FC adapter ports or node ports. For example, a dual-port FC
HBA has one WWNN and two WWPNs.
Unlike an FC address, which is assigned dynamically, a WWN is a static name for
each device on an FC network. WWNs are similar to the Media Access Control
(MAC) addresses used in IP networking. WWNs are burned into the hardware or
assigned through software. Several configuration definitions in an FC SAN use
WWN for identifying storage systems and FC HBAs. WWNs are critical for FC SAN
configuration as each node port has to be registered by its WWN before the FC
SAN recognizes it.
The name server in an FC SAN environment keeps the association of WWNs to the
dynamically created FC addresses for node ports. The illustration on the slide
illustrates the WWN structure examples for a storage system and an HBA.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 309
FC Architecture Lesson
Structure and Organization of FC Data
SOF 4
Bytes
Frame
Header 24
Bytes
Data Field
0-2112
Bytes
CRC 4 Bytes
EOF 4
Bytes
FC Data Structure Description
Exchange

Enables two N_Ports to identify and manage a set of
information units
 Information unit: upper layer protocol-specific
information that is sent to another port to perform
certain operation
 Each information unit maps to a sequence

Includes one or more sequences
Sequence

Contiguous set of frames that correspond to an
information unit
Frame

Fundamental unit of data transfer

Each frame consists of five parts: SOF, frame header,
data field, CRC, and EOF
Notes
Exchange: An exchange operation enables two node ports to identify and manage
a set of information units. Each upper layer protocol (ULP) has its protocol-specific
information that must be sent to another port to perform certain operations. This
protocol-specific information is called an information unit. The structure of these
information units is defined in the FC-4 layer. This unit maps to a sequence. An
exchange is composed of one or more sequences.
Sequence: A sequence refers to a contiguous set of frames that are sent from one
port to another. A sequence corresponds to an information unit, as defined by the
ULP.
Information Storage and Management (ISM) v4
Page 310
© Copyright 2019 Dell Inc.
FC Architecture Lesson
Frame: A frame is the fundamental unit of data transfer at FC-2 layer. An FC frame
consists of five parts: start of frame (SOF), frame header, data field, cyclic
redundancy check (CRC), and end of frame (EOF). The SOF and EOF act as
delimiters. The frame header is 24 bytes long and contains addressing information
for the frame. The data field in an FC frame contains the data payload, up to 2,112
bytes of actual data – usually the SCSI data. The CRC checksum facilitates error
detection for the content of the frame. This checksum verifies data integrity by
checking whether the content of the frames is received correctly. The CRC
checksum is calculated by the sender before encoding at the FC-1 layer. Similarly,
it is calculated by the receiver after decoding at the FC-1 layer.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 311
FC Architecture Lesson
Fabric Login Types
Fabric services define three login types:

Fabric login (FLOGI)
 Occurs between an N_Port and an F_Port
 Node sends a FLOGI frame with WWN to Fabric Login Server on switch
 Node obtains FC address from switch
 Immediately after FLOGI, N_Port registers with Name Server on switch
 N_Port queries name server about all other logged in ports

Port login (PLOGI)
 Occurs between two N_Ports to establish a session
 Exchange service parameters relevant to the session

Process login (PRLI)
 Occurs between two N_Ports to exchange ULP related parameters
Notes
Fabric Login (FLOGI): It is performed between an N_Port and an F_Port. To log
on to the fabric, a node sends a FLOGI frame with the WWNN and WWPN
parameters to the login service at the predefined FC address FFFFFE (Fabric
Login Server). In turn, the switch accepts the login and returns an Accept (ACC)
frame with the assigned FC address for the node. Immediately after the FLOGI, the
N_Port registers itself with the local Name Server on the switch, indicating its
WWNN, WWPN, port type, class of service, assigned FC address, and so on. After
the N_Port has logged in, it can query the name server database for information
about all other logged in ports.
Port Login (PLOGI): It is performed between two N_Ports to establish a session.
The initiator N_Port sends a PLOGI request frame to the target N_Port, which
accepts it. The target N_Port returns an ACC to the initiator N_Port. Next, the
N_Ports exchange service parameters relevant to the session.
Information Storage and Management (ISM) v4
Page 312
© Copyright 2019 Dell Inc.
FC Architecture Lesson
Process Login (PRLI): It is also performed between two N_Ports. This login
relates to the FC-4 ULPs, such as SCSI. If the ULP is SCSI, N_Ports exchange
SCSI-related service parameters.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 313
Topologies, Link Aggregation and Zoning Lesson
Topologies, Link Aggregation and Zoning Lesson
Introduction
This lesson presents FC SAN topologies such as single-switch, mesh, and coreedge. This lesson also focuses on the types of zoning.
This lesson covers the following topics:

Single-switch topology

Mesh topology

Core-edge topology

Link aggregation

Types of zoning
Information Storage and Management (ISM) v4
Page 314
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Topologies, Link Aggregation and Zoning
Video: FC Topologies Including Link Aggregation and Zoning
The video is located at
https://edutube.emc.com/Player.aspx?vno=ZvP288ft8adIH2wQDuFL6w
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 315
Topologies, Link Aggregation and Zoning Lesson
Single-switch Topology
Single Switch Fabric
FC Director
VM
VM
Hypervisor Kernel
Compute System
Compute System
Storage System

Fabric consists of only a single switch

Both compute systems, and storage systems connect to same switch

No ISLs are required for compute-to-storage traffic

Every switch port is usable for node connectivity
Notes
FC switches (including FC directors) may be connected in various ways to form
different fabric topologies. Each topology provides certain benefits.
Information Storage and Management (ISM) v4
Page 316
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
In a single-switch topology, the fabric consists of only a single switch. Both the
compute systems and the storage systems are connected to the same switch. A
key advantage of a single-switch fabric is that it does not need to use any switch
port for ISLs. Therefore, every switch port is usable for compute system or storage
system connectivity. Further, this topology helps eliminate FC frames traveling over
the ISLs and therefore eliminates the ISL delays.
A typical implementation of a single-switch fabric would involve the deployment of
an FC director. FC directors are high-end switches with a high port count. When
extra switch ports are needed over time, new ports can be added through add-on
line cards (blades) in spare slots available on the director chassis. To some extent,
a bladed solution alleviates the port count scalability problem inherent in a singleswitch topology.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 317
Topologies, Link Aggregation and Zoning Lesson
Mesh Topology
Full Mesh Topology
Full Mesh Fabric
VM
VM
APP
APP
OS
OS
VMM
VMM
FC Switches
Hypervisor Kernel
Compute System
Compute System
Storage System

Each switch is connected to every other switch

Maximum of one ISL is required

Compute systems and storage systems can be connected to any switch
Partial Mesh Topology
Information Storage and Management (ISM) v4
Page 318
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Partial Mesh Fabric
VM
VM
APP
APP
OS
OS
VMM
VMM
FC Switches
Hypervisor Kernel
Compute System
Compute System
Storage System

Not all the switches are connected to every other switch

Several ISLs may be required
Notes
In a full mesh, every switch is connected to every other switch in the topology.
A full mesh topology may be appropriate when the number of switches that are
involved is small. A typical deployment would involve up to four switches or
directors, with each of them servicing highly localized compute-to-storage traffic. In
a full mesh topology, a maximum of one ISL or hop is required for compute-tostorage traffic.
However, with the increase in the number of switches, the number of switch ports
that are used for ISL also increases. This process reduces the available switch
ports for node connectivity.
In a partial mesh topology, not all the switches are connected to every other switch.
In this topology, several hops or ISLs may be required for the traffic to reach its
destination.
Partial mesh offers more scalability than full mesh topology. However, without
proper placement of compute and storage systems, traffic management in a partial
mesh fabric might be complicate. Also ISLs could become overloaded due to
excessive traffic aggregation.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 319
Topologies, Link Aggregation and Zoning Lesson
Information Storage and Management (ISM) v4
Page 320
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Core-Edge Topology
Notes
The edge tier is composed of switches and offers an inexpensive approach to
adding more compute systems in a fabric. The edge-tier switches are not
connected to each other. Each switch at the edge tier is attached to a switch at the
core tier through ISLs.
The core tier is composed of directors that ensure high fabric availability. Also,
typically all traffic must either traverse this tier or terminate at this tier. In this
configuration, all storage systems are connected to the core tier, enabling computeto-storage traffic to traverse only one ISL. Compute systems that require high
performance may be connected directly to the core tier and therefore avoid ISL
delays.The core-edge topology increases connectivity within the FC SAN while
conserving the overall port utilization. It eliminates the need to connect edge
switches to other edge switches over ISLs.
Reduction of ISLs can greatly increase the number of node ports that can be
connected to the fabric. If fabric expansion is required, then administrators would
need to connect extra edge switches to the core. The core of the fabric is also
extended by adding more switches or directors at the core tier. Based on the
number of core-tier switches, this topology has different variations, such as singlecore topology and dual-core topology. To transform a single-core topology to dualcore, new ISLs are created to connect each edge switch to the new core switch in
the fabric.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 321
Topologies, Link Aggregation and Zoning Lesson
Link Aggregation

Combines multiple ISLs into a single logical ISL (port-channel)
– Provides higher throughput than a single ISL could provide
– Distributes network traffic over ISLs, ensuring even ISL utilization
H1-5Gb/s
H2-1.5Gb/s
H3-2Gb/s
H4-4.5Gb/s
H1-5Gb/s
H2-1.5Gb/s
H4-4.5Gb/s
FC Switch
FC Switch
{H1, S1}
{H1, S1}
{H4, S4}
3 ISLs(No Aggregation)
{H2, S2}
ISL
Aggregation
Port-Channel Bandwidth = 24 Gb/s
{H4, S4}
ISL Bandwidth = 8Gb/s
{H2, S2}
{H3, S3}
{H3, S3}
FC Switch
FC Switch
S1-5Gb/s
H3-2Gb/s
S2-1.5Gb/s
S3-2Gb/s
S4-4.5Gb/s
S1-5Gb/s
S2-1.5Gb/s
S3-2Gb/s
S4-4.5Gb/s
Notes
Link aggregation combines two or more parallel ISLs into a single logical ISL,
called a port-channel, yielding higher throughput than a single ISL could provide.
For example, the aggregation of 10 ISLs into a single port-channel provides up to
160 Gb/s throughput assuming the bandwidth of an ISL is 16 Gb/s. Link
aggregation optimizes fabric performance by distributing network traffic across the
shared bandwidth of all the ISLs in a port-channel. This allows the network traffic
for a pair of node ports to flow through all the available ISLs in the port-channel
rather than restricting the traffic to a specific, potentially congested ISL. The
number of ISLs in a port channel can be scaled depending on application’s
performance requirement.
Information Storage and Management (ISM) v4
Page 322
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Example Notes
This image illustrates two examples.
The example on the left is based on an FC SAN infrastructure with no link
aggregation enabled.

Four HBA ports H1, H2, H3, and H4 have been configured to generate I/O
activity to four storage system ports S1, S2, S3, and S4 respectively.

The HBAs and the storage systems are connected to two separate FC switches
with three ISLs between the switches.

Let us assume that the bandwidth of each ISL is 8 Gb/s and the data
transmission rate for the port-pairs {H1,S1}, {H2,S2}, {H3,S3}, and {H4,S4} are
5 Gb/s, 1.5 Gb/s, 2 Gb/s, and 4.5 Gb/s.
Without link aggregation, the fabric typically assigns a particular ISL for each of the
port-pairs in a round-robin fashion. It is possible that port-pairs {H1,S1} and {H4,S4}
are assigned to the same ISL in their respective routes. The other two ISLs are
assigned to the port-pairs {H2,S2} and {H3,S3}. Two of the three ISLs are underutilized, whereas the third ISL is saturated and becomes a performance bottleneck
for the port-pairs assigned to it.
The example on the right has aggregated the three ISLs into a port-channel that
provides throughput up to 24 Gb/s. Network traffic for all the port-pairs are
distributed over the ISLs in the port-channel, which ensures even ISL utilization.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 323
Topologies, Link Aggregation and Zoning Lesson
Zoning
Definition: Zoning
A logical private path between node ports in a fabric.
Zone 1
Compute System
FC SAN
VM
Storage System
VM
Storage System port
Hypervisor Kernel
Compute System
Zone 2
FC HBA Port

Each zone contains members (FC HBA and storage system ports)

Benefits:
 Security
 Restricts RSCN traffic
Information Storage and Management (ISM) v4
Page 324
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Notes
Zoning is a logical private path between node ports in a fabric. Whenever a change
takes place in the name server database, the fabric controller sends a Registered
State Change Notification (RSCN) to all the nodes impacted by the change. If
zoning is not configured, the fabric controller sends the RSCN to all the nodes in
the fabric. Involving the nodes that are not impacted by the change increases the
amount of fabric-management traffic.
For a large fabric, the amount of FC traffic generated due to this process can be
significant and might impact the compute-to-storage data traffic. Zoning helps to
limit the number of RSCNs in a fabric. In the presence of zoning, a fabric sends the
RSCN to only those nodes in a zone where the change has occurred.
Zoning also provides access control, along with other access control mechanisms,
such as LUN masking. Zoning provides control by enabling only the members in
the same zone to establish communication with each other.
Zone members, zones, and zone sets form the hierarchy that is defined in the
zoning process. A zone set is composed of a group of zones that can be activated
or deactivated as a single entity in a fabric. Multiple zone sets may be defined in a
fabric, but only one zone set can be active at a time.
Members are the nodes within the FC SAN that can be included in a zone. FC
switch ports, FC HBA ports, and storage system ports can be members of a zone.
A port or node can be a member of multiple zones. Nodes that are distributed
across multiple switches in a switched fabric may also be grouped into the same
zone. Zone sets are also referred to as zone configurations.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 325
Topologies, Link Aggregation and Zoning Lesson
Types of Zoning
The illustration shows three types of zoning on an FC network.
VM
VM
Switch Domain = 15
APP
AP
P
Port 5
OS
OS
VMM
VMM
Zone 2
Hypervisor Kernel
FC
Switch
Port 1
Compute
System
VM
VM
APP
AP
P
OS
OS
VMM
VMM
Port 12
Port 9
Hypervisor Kernel
Compute
System
Storage System
WWN 10:00:00:00:C9:20:DC:40
Zone 3
WWN 10:00:00:00:C9:20:DC:56
WWN 50:06:04:82:E8:91:2B:9E
Zone 1
Compute
System
WWN 10:00:00:00:C9:20:DC:82
Zone 1 (WWN Zone) =10:00:00:00:C9:20:DC:82; 50:06:04:82:E8:91:2B:9E
Zone 2 (Port Zone) = 15,5;15,12
Zone 3 (Mixed Zone) =10:00:00:00:C9:20:DC:56; 15,12
The three types of zoning are:
WWN Zoning
Uses World Wide Names to define zones. The zone members are the unique
WWN addresses of the FC HBA and its targets (storage systems). A major
advantage of WWN zoning is its flexibility. If an administrator moves a node to
another switch port in the fabric, the node maintains connectivity to its zone
partners without having to modify the zone configuration. This functionality is
possible because the WWN is static to the node port.
Port Zoning
Uses the switch port ID to define zones. In port zoning, access to node is
determined by the physical switch port to which a node is connected. The zone
members are the port identifiers (switch domain ID and port number) to which FC
HBA and its targets (storage systems) are connected. If a node is moved to
another switch port in the fabric, port zoning must be modified to enable the node,
in its new port, to participate in its original zone. However, if an FC HBA or storage
system port fails, an administrator has to replace the failed device without changing
the zoning configuration.
Information Storage and Management (ISM) v4
Page 326
© Copyright 2019 Dell Inc.
Topologies, Link Aggregation and Zoning Lesson
Mixed Zoning
Combines the qualities of both WWN zoning and port zoning. Using mixed zoning
enables a specific node port to be tied to the WWN of another node.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 327
SAN Virtualization Lesson
SAN Virtualization Lesson
Introduction
This lesson presents an overview of Virtual SAN (VSAN), its configuration, VSAN
trunking, and VSAN tagging. It also focuses on concepts in practice for FC SAN
connectivity.
This lesson covers the following topics:

Block-level storage virtualization

Virtual SAN (VSAN) overview
Information Storage and Management (ISM) v4
Page 328
© Copyright 2019 Dell Inc.
SAN Virtualization Lesson
SAN Virtualization
Video: Virtualization in FC SAN
The video is located at
https://edutube.emc.com/Player.aspx?vno=guMa8RQ1SE/1aPg/kAy3Gg
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 329
SAN Virtualization Lesson
Block-level Storage Virtualization
VM
VM
VM
VM
Compute
Systems
Hypervisor
Hypervisor
Virtual Volume
FC SAN
Virtualization
Appliance
Storage Pool
LUN
LUN
LUN
Storage
System
Storage System
LUN
The figure on the slide shows two compute systems, each of which has one virtual
volume assigned. These virtual volumes are mapped to the LUNs in the storage
systems. When an I/O is sent to a virtual volume, it is redirected to the mapped
LUNs through the virtualization layer at the FC SAN. Depending on the capabilities
of the virtualization appliance, the architecture may allow for more complex
mapping between the LUNs and the virtual volumes.

Provides a virtualization layer in SAN
 Abstracts block-based storage systems
 Aggregates LUNs to create storage pool
Information Storage and Management (ISM) v4
Page 330
© Copyright 2019 Dell Inc.
SAN Virtualization Lesson

Virtual volumes from storage pool are assigned to compute systems
 Virtualization layer maps virtual volumes to LUNs

Benefits:
 Online expansion of virtual volumes
 Non-disruptive data migration
Notes
Block-level storage virtualization aggregates block storage devices (LUNs) and
enables provisioning of virtual storage volumes, independent of the underlying
physical storage. A virtualization layer, which exists at the SAN, abstracts the
identity of block-based storage systems and creates a storage pool by aggregating
LUNs from the storage systems.
Virtual volumes are created from the storage pool and assigned to the compute
systems. Instead of being directed to the LUNs on the individual storage systems,
the compute systems are directed to the virtual volumes provided by the
virtualization layer. The virtualization layer maps the virtual volumes to the LUNs on
the individual storage systems.
The compute systems remain unaware of the mapping operation and access the
virtual volumes as if they were accessing the physical storage attached to them.
Typically, the virtualization layer is managed via a dedicated virtualization
appliance to which the compute systems and the storage systems are connected.
Block-level storage virtualization enables extending the virtual volumes nondisruptively to meet application’s capacity scaling requirements. It also provides the
advantage of non-disruptive data migration. In a traditional SAN environment, LUN
migration from one storage system to another is an offline event.
After migration, the compute systems are updated to reflect the new storage
system configuration. In other instances, processor cycles at the compute system
were required to migrate data from one storage system to the other, especially in a
multivendor environment.
With a block-level storage virtualization solution in place, the virtualization layer
handles the migration of data, which enables LUNs to remain online and accessible
while data is migrating. No physical changes are required because the compute
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 331
SAN Virtualization Lesson
system still points to the same virtual volume on the virtualization layer. However,
the mapping information on the virtualization layer should be changed. These
changes can be executed dynamically and are transparent to the end user.
Information Storage and Management (ISM) v4
Page 332
© Copyright 2019 Dell Inc.
SAN Virtualization Lesson
Virtual SAN/Virtual Fabric
Definition: VSAN
VSAN 10
VSAN 20
Compute Systems
VM
VM
APP
APP
OS
OS
VMM
VMM
Hypervisor Kernel
Compute Systems
VM
VM
APP
APP
OS
OS
VMM
VMM
VM
VM
APP
APP
OS
OS
VMM
VMM
Hypervisor Kernel
Hypervisor Kernel
VM
VM
APP
APP
OS
OS
VMM
VMM
Hypervisor Kernel
FC SAN
Storage System
Storage System

Each VSAN has its own fabric services, configuration, and set of FC addresses

VSANs improve SAN security, scalability, availability, and manageability
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 333
SAN Virtualization Lesson
Notes
In a VSAN, a group of node ports communicate with each other using a virtual
topology that is defined on the physical SAN. Multiple VSANs may be created on a
single physical SAN. Each VSAN behaves and is managed as an independent
fabric. Each VSAN has its own fabric services, configuration, and set of FC
addresses. Fabric-related configurations in one VSAN do not affect the traffic in
another VSAN. A VSAN may be extended across sites, enabling communication
among a group of nodes, in either site with a common set of requirements.
VSANs improve SAN security, scalability, availability, and manageability. VSANs
provide enhanced security by isolating the sensitive data in a VSAN and by
restricting the access to the resources located within that VSAN. For example, a
cloud provider typically isolates the storage pools for multiple cloud services by
creating multiple VSANs on an FC SAN.
Further, the same FC address can be assigned to nodes in different VSANs, thus
increasing the fabric scalability. The events causing traffic disruptions in one VSAN
are contained within that VSAN and are not propagated to other VSANs. VSANs
facilitate an easy, flexible, and less expensive way to manage networks.
Configuring VSANs is easier and quicker compared to building separate physical
FC SANs for various node groups. To regroup nodes, an administrator changes the
VSAN configurations without moving nodes and recabling.
Information Storage and Management (ISM) v4
Page 334
© Copyright 2019 Dell Inc.
SAN Virtualization Lesson
VSAN Configuration

Define VSANs on fabric switch with specific VSAN IDs

Assign VSAN IDs to F_Ports to include them in the VSANs

An N_Port connecting to an F_Port in a VSAN becomes a member of that
VSAN

Switch forwards FC frames between F_Ports that belong to the same VSAN
Notes
To configure VSANs on a fabric, an administrator first needs to define VSANs on
fabric switches. Each VSAN is identified with a specific number called VSAN ID.
The next step is to assign a VSAN ID to the F_Ports on the switch. By assigning a
VSAN ID to an F_Port, the port is included in the VSAN. In this manner, multiple
F_Ports can be grouped into a VSAN. For example, an administrator may group
switch ports (F_Ports) 1 and 2 into VSAN 10 (ID) and ports 6–12 into VSAN 20
(ID). If an N_Port connects to an F_Port that belongs to a VSAN, it becomes a
member of that VSAN. The switch transfers FC frames between switch ports that
belong to the same VSAN.
VSAN versus Zone:

Both VSANs and zones enable node ports within a fabric to be logically
segmented into groups. But they are not same and their purposes are different.
There is a hierarchical relationship between them. An administrator first assigns
physical ports to VSANs and then configures independent zones for each
VSAN. A VSAN has its own independent fabric services, but the fabric services
are not available on a per-zone basis.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 335
SAN Virtualization Lesson
VSAN Trunking

Allows network traffic from multiple VSANs to traverse a single ISL (trunk link)

Enables an E_Port (trunk port) to send or receive multiple VSAN traffic over a
trunk link

Reduces the number of ISLs between switches that are configured with multiple
VSANs
VSAN 10,20,30
FC Switch
VSAN 10
Traffic
FC Switch
VSAN
20
Traffic
FC Switch
VSAN 10,20,30
VSAN 30
Traffic
VSAN 10,20,30
Without VSAN Trunking
Trunk Link(VSAN
10,20,30 Traffic)
VSAN 10,20,30
FC SWitch
With VSAN Trunking
The illustration shows a VSAN trunking configuration that is contrasted with a
network configuration without VSAN trunking. In both the cases, the switches have
VSAN 10, VSAN 20, and VSAN 30 configured. If VSAN trunking is not used, three
ISLs are required to transfer traffic between the three distinct VSANs. When
trunking is configured, a single ISL is used to transfer all VSAN traffic.
Notes
VSAN trunking allows network traffic from multiple VSANs to traverse a single ISL.
It supports a single ISL to permit traffic from multiple VSANs along the same path.
The ISL through which multiple VSANs traffic travels is called a trunk link. VSAN
trunking enables a single E_Port to be used for sending or receiving traffic from
multiple VSANs over a trunk link. The E_Port capable of transferring multiple
VSANs traffic is called a trunk port. The sending and receiving switches must have
at least one trunk E_Port configured for all or a subset of the VSANs defined on the
switches.
Information Storage and Management (ISM) v4
Page 336
© Copyright 2019 Dell Inc.
SAN Virtualization Lesson
VSAN trunking eliminates the need to create dedicated ISL(s) for each VSAN. It
reduces the number of ISLs when the switches are configured with multiple
VSANs. As the number of ISLs between the switches decreases, the number of
E_Ports used for the ISLs also reduces. By eliminating needless ISLs, the
utilization of the remaining ISLs increases. The complexity of managing the FC
SAN is also minimized with a reduced number of ISLs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 337
SAN Virtualization Lesson
VSAN Tagging
Definition: VSAN Tagging
A process of adding or removing a tag to the FC frames that contains
VSAN-specific information.
Associated with VSAN trunking, it helps isolate FC frames from multiple VSANs
that travel through and share a trunk link.
Whenever an FC frame enters an FC switch, it is tagged with a VSAN header
indicating the VSAN ID of the switch port (F_Port) before sending the frame down
to a trunk link. The receiving FC switch reads the tag and forwards the frame to the
destination port that corresponds to that VSAN ID. The tag is removed once the
frame leaves a trunk link to reach an N_Port.
VM
VM
APP
APP
FC Switch
OS
OS
VMM
VMM
Hypervisor Kernel
VM
APP
OS
OS
VMM
VMM
Hypervisor Kernel
VSAN 10 Traffic
VSAN 20 Traffic
VM
APP
Compute System
Compute System
VSAN 20 Traffic
VSANtags are added to FC frames before transmitting through
trunk link
VSAN 10 Traffic
ISLcarries tagged traffic from multiple VSANs
Trunk Link
VSANtags are removed when FC frames exit trunk link
Storage System
Storage System
VSAN 10 Traffic
VSAN 20 Traffic
FC Switch
Information Storage and Management (ISM) v4
Page 338
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Connectrix

Dell EMC VPLEX
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 339
Concepts in Practice Lesson
Concepts In Practice
Concepts In Practice
Connectrix

Group of networked storage connectivity products that support NVMe over FC
technology

Products under Connectrix brand:
 Directors: Ideal for largest mission-critical storage area network
environments
 Switches: Ideal for departmental or edge storage area networks
Dell EMC VPLEX

Provides solution for block-level storage virtualization and data migration both
within and across data centers
Information Storage and Management (ISM) v4
Page 340
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson

Provides the capability to mirror data of a virtual volume both within and across
locations

VS6 engine with VPLEX for all-flash model provides the fastest and most
scalable VPLEX solution for all-flash systems

Enables organizations to move cold data to inexpensive cloud storage
Dell EMC Connectrix
Connectrix: A group of networked storage connectivity products. Dell EMC offers
the following connectivity products under the Connectrix brand:
Directors: Ideal for largest mission-critical storage area network environments.
They offer high port density and high component redundancy. They allow physical
and virtual servers to share storage resources securely. They provide up to 32
Gbps Fibre Channel connectivity. They provide high-availability, maximum
scalability, and deliver high performance to keep pace with all-flash storage
environments.
Switches: Ideal for departmental or edge storage area networks. It provides
foundation for growth in smaller environments to deployment in large data centers.
They support up to 32 Gbps Fibre Channel connectivity. They provide high
availability through redundant connections and scales with 1U and 2U models.
Dell EMC VPLEX
Provides solution for block-level storage virtualization and data mobility both within
and across data centers. It forms a pool of distributed block storage resources and
enables creating virtual storage volumes from the pool. These virtual volumes are
then allocated to the compute systems.
VPLEX provides nondisruptive data mobility among storage systems to balance the
application workload and to enable both local and remote data access. It uses a
unique clustering architecture and advanced data caching techniques. They enable
multiple compute systems that are located across two locations to access a single
copy of data. Data migration with VPLEX can be done without any downtime,
saving countless weekends of maintenance downtime and IT resources. VPLEX
enables IT organizations to build modern data center infrastructure that is: Always
available even in the face of disasters Agile in responding to business requirements
Non-disruptive when adopting latest storage technology
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 341
Concepts in Practice Lesson
The new VS6 engine with VPLEX for all-flash model provides the fastest and most
scalable VPLEX solution for all-flash systems. VPLEX also enables organizations
to move cold data to inexpensive cloud storage.
Information Storage and Management (ISM) v4
Page 342
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. Which layer of FC protocol stack provides FC addressing, structure, and
organization of data?
A. FC - 0 - Layer
B. FC - 1 - Layer
C. FC - 2 - Layer
D. FC - 4 - Layer
2. Identify the topology that requires maximum of one ISL for compute to storage
communication. Select all that applies.
A. Full mesh topology
B. Single-switch topology
C. Partial mesh topology
D. Core-edge topology
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 343
Summary
Summary
Information Storage and Management (ISM) v4
Page 344
© Copyright 2019 Dell Inc.
IP and FCoE SAN
Introduction
This module focuses on IP SAN protocols such as Internet SCSI (iSCSI) and Fiber
Channel over IP (FCIP), components, and connectivity. It also covers details of
virtual LAN (VLAN) and reference models for communication.
Upon completing this module, you will be able to:





Describe the reference models
Explain iSCSI protocol, network components, and connectivity
Explain VLANs
Explain FCIP protocol, connectivity, and configuration
Explain FCoE protocol
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 345
Overview of TCP/IP Lesson
Overview of TCP/IP Lesson
Introduction
This lesson presents the Open Systems Interconnect (OSI) and the Transmission
Control Protocol/Internet Protocol (TCP/IP) reference model. It also covers details
of network protocols and connection establishment process.
This lesson covers the following topics:

Reference models for network communication

Network protocols

Three-way handshake process
Information Storage and Management (ISM) v4
Page 346
© Copyright 2019 Dell Inc.
Overview of TCP/IP Lesson
Overview of TCP/IP
OSI Reference Model
The OSI reference model is a logical structure for network operations standardized
by the International Standards Organization (ISO). Each layer in the OSI reference
model only interacts directly with the layer immediately beneath it, and provides
facilities for use by the layer above it. The following layers make up the OSI model:


A logical structure
for network
operations
The OSI model
organizes the
communications
process into seven
different layers

Protocols are within
the layers

Layers 4-7 provide
end to end
communication

End to
End
Network
L7
Application Layer
L6
Presentation Layer
L5
Session Layer
L4
Transport Layer
L3
Network Layer
L2
Data Link Layer
L1
Physical Layer
Layers 1-3 are used
for network access
providing packet, frame and bit level communication
Notes
Each layer is described as follows:
1. Physical Layer - Defines the electrical and physical specifications for devices.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 347
Overview of TCP/IP Lesson
2. Data Link Layer - Provides the functional and procedural means to transfer data
between network entities. It also detects and possibly correct errors that may
occur in the Physical Layer.
3. Network Layer - Transfers variable length data sequences from a source to
destination through one or more networks while also maintaining a quality of
service requested by the Transport Layer.
4. Transport Layer - Provides transparent transfer of data between end users,
providing reliable data transfer services to the upper layers.
5. Session Layer - Controls the connections between computers. It establishes,
manages, and terminates the connections between the local and remote
application.
6. Presentation Layer - Establishes a context between the Application layer
entities in which the high-layer entities can use different syntax and semantics.
7. Application Layer - Provides a user interface that enables user to access the
network and applications.
Information Storage and Management (ISM) v4
Page 348
© Copyright 2019 Dell Inc.
Overview of TCP/IP Lesson
TCP/IP Reference Model
Application Layer
Transport Layer
Network Layer
Link Layer
TCP/IP is a hierarchical protocol suite that is named after its two primary protocols
Transmission Control Protocol (TCP) and Internet Protocol (IP). It is made up of
four layers as specified in the image.

TCP/IP is a 4-layer hierarchical model
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 349
Overview of TCP/IP Lesson

An example of an implementation of the OSI reference model

Also known as Internet Protocol Suite
Notes
The four layers are described as follows:

The link layer is used to describe the local network topology and the interfaces
needed to affect transmission of Internet layer datagrams to next-neighbor
hosts.

The network layer is responsible for end-to-end communications and delivery of
packets across multiple network links.

The transport layer provides process to process delivery of the entire message.

The application layer enables users to access the network.
Information Storage and Management (ISM) v4
Page 350
© Copyright 2019 Dell Inc.
Overview of TCP/IP Lesson
Comparing Reference Models
The purpose of the reference models is to show how to facilitate communication
between different systems without requiring changes to the logic of the underlying
architecture.
Application Layer
Presentation Layer
Application Layer
Session Layer
Transport Layer
Transport Layer
Network Layer
Internet Layer
Data Link Layer
Link Layer
Physical Layer

Facilitates communication between different systems

Layered architecture

Standard protocols and interfaces

Example
– OSI
– TCP/IP
Notes
The purpose of the reference models is to show how to facilitate communication
between different systems without requiring changes to the logic of the underlying
architecture. To understand the complex system and for simplification, the
reference models are implemented as a layered structure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 351
Overview of TCP/IP Lesson
The OSI and the TCP/IP reference models have much in common. The
architectural layers form a hierarchy and items are listed in order by rank. Higher
layers depend upon services from lower layers, and lower layers provide services
for upper layers. Also, the functionality of layers is roughly similar, except a few.
The presentation and the session layer of the OSI reference model was combined
with the application layer and represented as the application layer in the TCP/IP
Model. The model also does not distinguish the physical and the data link layer.
To understand the complex system and for simplification, the reference models are
implemented as a layered structure. The Open Systems Interconnection (OSI) and
TCP/IP reference models are widely adopted and are important network
architectures (reference model). Both of them defines the essential features of
network services and enhanced functionality.OSI Model is a logical structure for
network operations standardized by the International Standards Organization
(ISO).

The OSI model is a layered framework for the design of a network system that
enables communication between all types of systems.

TCP/IP is a hierarchical protocol suite that is made up of interactive modules,
providing specific functionality.
Information Storage and Management (ISM) v4
Page 352
© Copyright 2019 Dell Inc.
Overview of TCP/IP Lesson
Network Layer and IP
IP is one of the major protocols in the Transmission Control Protocol (TCP)/Internet
Protocol (IP) protocol suite. This protocol works at layer 3, the network layer of the
OSI model and at the Internet layer of the TCP/IP model. Thus, this protocol is
responsible for end-to-end communication and delivery of packets across multiple
network links based on their logical addresses.
The current versions are:

Internet Protocol version 4 (IPv4)
 32-bit address (example: 192.168.1.12)

Internet Protocol version 6 (IPv6)
 128-bit address (example: 2002:ac18:af02:00f4:020e:cff:fe6e:d527
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 353
Overview of TCP/IP Lesson
Connection Establishment: Three-way handshake
The transport layer is the heart of the TCP/IP protocol suite. Due to the use of
connection-oriented protocol TCP, the layer provides reliable, process-to-process,
and full-duplex service.
Transmission Control Protocol (TCP) explicitly defines the connection
establishment process. The connection establishment in TCP is called three-way
handshaking. Three-way handshaking is a process to negotiate the sequence and
acknowledgment fields and start the session. The process consists of the following
steps:

The client initiates the connection by sending the TCP SYN packet to the
destination host.
In the illustration,
 SYN refers to synchronous and ACK refers to acknowledgement
 The packet contains the random sequence number, which marks the
beginning of the sequence numbers of data that the client will transmit
 This sequence number is called the initial sequence number

The server, which is a destination host, receives the packet, and responds with
its own sequence number. The response also includes the acknowledgment
number, which is client’s sequence number that is incremented by 1. That is
SYN+ACK segment is sent

Client acknowledges the response of the server by sending the
acknowledgment ACK segment. It acknowledges the receipt of the second
segment with the ACK flag
Information Storage and Management (ISM) v4
Page 354
© Copyright 2019 Dell Inc.
Overview of TCP/IP Lesson
Listening Server
Client
SYN_SENT
Listening
SYN
SYN_RCVD
SYN ACK
Established
ACK
Established
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 355
Overview of IP SAN Lesson
Overview of IP SAN Lesson
Introduction
This lesson covers IP SAN and its protocols. It also focuses on the role of TCP/IP
in IP SAN.
This lesson covers the following topics:

Describe IP SAN

Describe the role of TCP/IP in IP SAN

List IP SAN protocols
Information Storage and Management (ISM) v4
Page 356
© Copyright 2019 Dell Inc.
Overview of IP SAN Lesson
Overview of IP SAN
IP SAN
Compute Systems
VM
APP
VM
APP
VM
APP
VM
APP
VM
APP
VM
APP
OS
OS
OS
OS
OS
OS
Hypervisor
Hypervisor
iSCSI
HBA
iSCSI
HBA
Hypervisor
iSCSI
HBA
IP
iSCSI Port
iSCSI Port
Storage Systems
Uses Internet Protocol (IP) for the transport of storage traffic. It transports block I/O
over an IP-based network.
Provides an efficient and dedicated point-to-point storage solution.
Typically runs over a standard IP-based network and uses the TCP/IP) for
communication, commonly:

Internet SCSI (iSCSI)

Fibre Channel over IP (FCIP)
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 357
Overview of IP SAN Lesson
Drivers of IP SAN
The following are drivers have led to the adoption of IP SAN:

Existing IP-based network infrastructure can be leveraged
 Reduced cost compared to deploying new FC SAN infrastructure

IP network makes it possible to extend or connect SANs over long distances

Many long-distance disaster recovery solutions already leverage IP-based
network

Many robust and mature security options are available for IP network
Notes
The advantages of FC SAN such as scalability and high performance come with
the additional cost of buying FC components, such as FC HBA and FC switches.
On the other hand IP is a matured technology and using IP as a storage networking
option provides several advantages. These are listed below:

Most organizations have an existing IP-based network infrastructure, which
could be used for storage networking. The use of existing network may be a
more economical option than deploying a new FC SAN infrastructure.

IP network has no distance limitation, which makes it possible to extend or
connect SANs over long distances. With IP SAN, organizations can extend the
geographical reach of their storage infrastructure and transfer data that are
distributed over wide locations.

Many long-distance disaster recovery (DR) solutions are already leveraging IPbased networks. In addition, many robust and mature security options are
available for IP networks.
Information Storage and Management (ISM) v4
Page 358
© Copyright 2019 Dell Inc.
Overview of IP SAN Lesson
Role of TCP/IP in IP SAN
As we know, the IP SAN protocols typically run over a standard Ethernet network
and uses the Transmission Control Protocol/Internet Protocol (TCP/IP) for
communication along with transport of storage traffic.
The entire process of communication is carried out by the encapsulation of SCSCI
commands into the TCP segments. As depicted in the image, iSCSI fits into the
network protocol stack and sits on top of the TCP/IP protocol stack. It takes SCSI
commands, data, and responses and encapsulates them into TCP segments for
transportation. Upon receiving iSCSI TCP segments, the iSCSI layer pulls out the
SCSI information and passes it to the SCSI driver software.
Application
Volume managers, file systems and so forth
SCSI
SCSI Command Descriptor Blocks, data and
responses
iSCSI
Build and receive iSCSI PDUs
TCP
Provides reliable transport and delivery, flow
control, ACKs; uses TCP port #s
IP
IP routing to help get data through network; uses
IP addresses
Ethernet
Frame switching, MAC Address, transport
connection to the physical layer
iSCSI Stack
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 359
Overview of IP SAN Lesson
IP SAN Protocols
Two primary protocols that leverage IP as the transport mechanism for block-level
data transmission are Internet SCSI (iSCSI) and Fibre Channel over IP (FCIP).
iSCSI
Compute Systems
VM
VM
VM
VM
VM
VM
APP
APP
APP
APP
APP
APP
OS
OS
OS
OS
OS
Hypervisor
Hypervisor
iSCSI
HBA
iSCSI
HBA
OS
Hypervisor
iSCSI
HBA
IP
iSCSI Port
iSCSI
Port
Storage Systems

IP-based protocol that enables transporting SCSI data over an IP network

Encapsulates SCSI I/O into IP packets and transports them using TCP/IP
FCIP
Information Storage and Management (ISM) v4
Page 360
© Copyright 2019 Dell Inc.
Overview of IP SAN Lesson
Compute System
Compute System
VM
VM
VM
VM
VM
VM
VM
VM
APP
APP
APP
APP
APP
APP
APP
APP
OS
OS
OS
OS
OS
OS
OS
OS
Hypervisor
Hypervisor
Hypervisor
Hypervisor
FC SAN
FCIP Tunnel
FC SAN
FCIP Gateway
LAN/WAN
FCIP Gateway
Storage System
Storage System

IP-based protocol that is used to interconnect distributed FC SAN islands over
an IP network

Encapsulates FC frames onto IP packet and transports over existing IP network

Enables transmission by tunneling data between FC SAN islands
Notes
iSCSI: It is widely adopted for transferring SCSI data over IP between compute
systems and storage systems and among the storage systems. It is relatively
inexpensive and easy to implement, especially environments in which an FC SAN
does not exist.
FCIP: Organizations are looking for ways to transport data over a long distance
between their disparate FC SANs at multiple geographic locations. One of the best
ways to achieve this goal is to interconnect geographically dispersed FC SANs
through reliable, high-speed links. This approach involves transporting the FC block
data over the IP infrastructure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 361
Overview of IP SAN Lesson
The FCIP standard has rapidly gained acceptance as a manageable, cost-effective
way to blend the best of the two worlds: FC SAN and the proven, widely deployed
IP infrastructure.
Information Storage and Management (ISM) v4
Page 362
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Lesson
Introduction
This lesson covers iSCSI network components and connectivity. It also covers
iSCSI protocol stack, iSCSI address and name, and iSCSI discovery. The lesson
also focuses on the virtual LAN (VLAN) and stretched VLAN.
This lesson covers the following topics:

iSCSI network components

iSCSI connectivity

iSCSI protocol stack

iSCSI address and name

iSCSI discovery

Virtual LAN (VLAN) and stretched VLAN
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 363
iSCSI Lesson
iSCSI
Video: iSCSI
The video is located at
https://edutube.emc.com/Player.aspx?vno=bB5O5rcjrZ447ADdHPxC0A
Information Storage and Management (ISM) v4
Page 364
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Overview
iSCSI is an IP-based protocol that establishes and manages connections between
compute systems and storage systems over IP.
It is an encapsulation of SCSI I/O over IP, where it encapsulates SCSI commands
and data into IP packets and transports them using TCP/IP.
It is widely adopted for transferring SCSI data over IP between compute systems
and storage systems and among the storage systems. iSCSI is relatively
inexpensive and easy to implement, especially environments in which an FC SAN
does not exist
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 365
iSCSI Lesson
Components of iSCSI Network
Key components for iSCSI communication are:
Compute Systems
VM
VM
VM
VM
VM
VM
APP
APP
APP
APP
APP
APP
OS
OS
OS
OS
OS
OS
Hypervisor
iSCSI
HBA
Hypervisor
iSCSI
HBA
Hypervisor
iSCSI
HBA
IP
iSCSI Port
iSCSI Port
Storage Systems

iSCSI initiators
 Example: iSCSI HBA

iSCSI targets
 Example: Storage system with iSCSI port

IP-based network
 Example: Gigabit Ethernet LAN
Information Storage and Management (ISM) v4
Page 366
© Copyright 2019 Dell Inc.
iSCSI Lesson
Types of iSCSI Initiator
Hardware and software initiators are types of iSCSI initiators that are used by the
host to access iSCSI targets.
Initiator Types
iSCSI hardware Initiator

iSCSI software Initiator
Standard NIC with software iSCSI adapter
 NIC provides network interface
 Software adapters provide iSCSI functionality
 Both iSCSI and TCP/IP processing require CPU cycles of compute system

TCP Offload Engine (TOE) NIC with software iSCSI adapter
 TOE NIC performs TCP/IP processing
 Software adapter provides iSCSI functionality
 iSCSI processing requires CPU cycles of compute system

iSCSI HBA
 Performs both iSCSI and TCP/IP processing
 Frees-up CPU cycles of compute system for business applications
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 367
iSCSI Lesson
Notes
The computing operations of the software iSCSI initiator are performed by the
server’s operating system. Whereas a hardware iSCSI initiator is a dedicated, hostbased network interface card (NIC) with the integrated resources to handle the
iSCSI processing functions. Following are the common examples of iSCSI
initiators:

Standard NIC with software iSCSI adapter: The software iSCSI adapter is an
operating system or hypervisor kernel-resident software. It uses an existing NIC
of the compute system to emulate an iSCSI initiator. It is least expensive and
easy to implement because most compute systems come with at least one, and
often with two embedded NICs. It requires only a software initiator for iSCSI
functionality. Because NICs provide standard networking function, both the
TCP/IP processing and the encapsulation of SCSI data into IP packets are
carried out by the CPU of the compute system. This functionality places more
overhead on the CPU. If a standard NIC is used in heavy I/O load situations, the
CPU of the compute system might become a bottleneck.

TOE NIC with software iSCSI adapter: A TOE NIC offloads the TCP/IP
processing from the CPU of a compute system and leaves only the iSCSI
functionality to the CPU. The compute system passes the iSCSI information to
the TOE NIC and then the TOE NIC sends the information to the destination
using TCP/IP. Although this solution improves performance, the iSCSI
functionality is still handled by a software adapter that requires CPU cycles of
the compute system.

iSCSI HBA: An iSCSI HBA is a hardware adapter with built-in iSCSI
functionality. It is capable of providing performance benefits over software iSCSI
adapters by offloading the entire iSCSI and TCP/IP processing from the CPU of
a compute system.
Information Storage and Management (ISM) v4
Page 368
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Connectivity
iSCSI implementations support two types of connectivity: native and bridged. The
connectivities are described here:
Native
Storage System
Compute System
VM
VM
Hypervisor
IP
iSCSI HBA
iSCSI Port

iSCSI initiators connect to iSCSI targets directly/through IP network

No FC component
Bridged
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 369
iSCSI Lesson
Storage System
Compute System
VM
VM
iSCSI Gateway
Hypervisor
IP
FC SAN
iSCSI HBA
FC Port

iSCSI initiators are attached to IP network

Storage systems are attached to FC SAN

iSCSI gateway provides bridging functionality
Native iSCSI: In this type of connectivity, the compute systems with iSCSI initiators
may be either directly attached to the iSCSI targets or connected through an IPbased network. FC components are not required for native iSCSI connectivity. The
figure on the left shows a native iSCSI implementation that includes a storage
system with an iSCSI port. The storage system is connected to an IP network. After
an iSCSI initiator is logged on to the network, it can access the available LUNs on
the storage system.
Bridged iSCSI: This type of connectivity enables the initiators to exist in an IP
environment while the storage systems remain in an FC SAN environment. It
enables the coexistence of FC with IP by providing iSCSI-to-FC bridging
functionality. The figure on the right illustrates a bridged iSCSI implementation. It
shows connectivity between a compute system with an iSCSI initiator and a
storage system with an FC port. As the storage system does not have any iSCSI
port, a gateway or a multiprotocol router is used. The gateway facilitates the
communication between the compute system with iSCSI ports and the storage
system with only FC ports. The gateway converts IP packets to FC frames and
conversely, thus bridging the connectivity between the IP and FC environments.
The gateway contains both FC and Ethernet ports to facilitate the communication
Information Storage and Management (ISM) v4
Page 370
© Copyright 2019 Dell Inc.
iSCSI Lesson
between the FC and the IP environments. The iSCSI initiator is configured with the
gateway’s IP address as its target destination. On the other side, the gateway is
configured as an FC initiator to the storage system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 371
iSCSI Lesson
Combining FC and Native iSCSI Connectivity
Typically, a storage system typically comes with both FC and iSCSI ports. The
combination enables both the native iSCSI connectivity and the FC connectivity in
the same environment and no bridge device is needed.
Compute System
VM
VM
Hypervisor
IP
iSCSI
Port
iSCSI
HBA
Storage System
Compute System
VM
VM
FC
HBA
FC
Port
Hypervisor
FC SAN
Information Storage and Management (ISM) v4
Page 372
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Protocol Stack
The image displays a model of iSCSI protocol layers and depicts the encapsulation
order of the SCSI commands for their delivery through a physical carrier.

SCSI is the command protocol that works at the application layer of the Open
System Interconnection (OSI) model

The initiators and the targets use SCSI commands and responses to talk to
each other

The SCSI commands, data, and status messages are encapsulated into TCP/IP
and transmitted across the network between the initiators and the targets
OSI Model
iSCSI initiator
iSCSI Target
Layer 7 Application
SCSI
Commands and Data
SCSI
Layer 5 Session
iSCSI
Login and Discovery
iSCSI
Layer 4 Transport
TCP
Windows and Segments
TCP
Layer 3 Network
IP
Packets
IP
Layer 2 Data Link
Frames
Ethernet
Ethernet
Interconnect
Ethernet
IP
TCP
iSCSI
SCSI
Data
Notes
The figure on the slide displays a model of iSCSI protocol layers and depicts the
encapsulation order of the SCSI commands for their delivery through a physical
carrier.SCSI is the command protocol that works at the application layer of the
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 373
iSCSI Lesson
Open System Interconnection (OSI) model. The initiators and the targets use SCSI
commands and responses to talk to each other. The SCSI commands, data, and
status messages are encapsulated into TCP/IP and transmitted across the network
between the initiators and the targets.
iSCSI is the session-layer protocol that initiates a reliable session between devices
that recognize SCSI commands and TCP/IP. The iSCSI session-layer interface is
responsible for handling login, authentication, target discovery, and session
management.
TCP is used with iSCSI at the transport layer to provide reliable transmission. TCP
controls message flow, windowing, error recovery, and retransmission. It relies
upon the network layer of the OSI model to provide global addressing and
connectivity. The OSI Layer 2 protocols at the data link layer of this model enable
node-to-node communication through a physical network.
Information Storage and Management (ISM) v4
Page 374
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Address and Name
An iSCSI address is
the path to iSCSI
initiator/target, which
is comprised of:
IQN: iSCSI Qualified Name

EUI: Extended Unique Identifier
Common Types of iSCSI Name
- iqn.2008-02.com.example:optional_string
An iSCSI
address is the
path to iSCSI
initiator/target,
which is
comprised of
- eui.0300732A32598D26
NAA: Network Address Authority
- naa.52004567BA64678D
– Location of
iSCSI initiator/target
o Combination of IP address and TCP port number
– iSCSI name
o Unique identifier for initiator/target in an iSCSI network
Notes
An iSCSI address is comprised of the location of an iSCSI initiator or target on the
network and the iSCSI name. The location is a combination of the host name or IP
address and the TCP port number. For iSCSI initiators, the TCP port number is
omitted from the address.
iSCSI name is a unique worldwide iSCSI identifier that is used to identify the
initiators and targets within an iSCSI network to facilitate communication. The
unique identifier can be a combination of the names of the department, application,
manufacturer, serial number, asset number, or any tag that can be used to
recognize and manage the iSCSI nodes. The following are three types of iSCSI
names commonly used:

iSCSI Qualified Name (IQN): An organization must own a registered domain
name to generate iSCSI Qualified Names. This domain name does not need to
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 375
iSCSI Lesson
be active or resolve to an address. It needs to be reserved to prevent other
organizations from using the same domain name to generate iSCSI names. A
date is included in the name to avoid potential conflicts caused by the transfer
of domain names. An example of an IQN is iqn.201504.com.example:optional_string. The optional string provides a serial number,
an asset number, or any other device identifiers. IQN enables storage
administrators to assign meaningful names to the iSCSI initiators and the iSCSI
targets, and therefore, manages those devices more easily.

Extended Unique Identifier (EUI): An EUI is a globally unique identifier based on
the IEEE EUI-64 naming standard. An EUI is composed of the eui prefix
followed by a 16-character hexadecimal name, such as
eui.0300732A32598D26.

Network Address Authority (NAA): NAA is another worldwide unique naming
format as defined by the International Committee for Information Technology
Standards (INCITS) T11 – Fibre Channel (FC) protocols and is used by Serial
Attached SCSI (SAS). This format enables the SCSI storage devices that
contain both iSCSI ports and SAS ports to use the same NAA-based SCSI
device name. An NAA is composed of the naa prefix followed by a hexadecimal
name, such as naa.52004567BA64678D. The hexadecimal representation has
a maximum size of 32 characters (128 bit identifier).
Information Storage and Management (ISM) v4
Page 376
© Copyright 2019 Dell Inc.
iSCSI Lesson
iSCSI Discovery
For iSCSI communication, initiator must discover location and name of targets on
the network.
iSCSI discovery commonly takes place in two ways:

iSCSI discovery commonly takes place in two ways
– Send Targets discovery
o Initiator is manually configured with the target’s network portal
o Initiator issues SendTargets command; target responds with required
parameters
– Internet Storage Name Service (iSNS)
o Initiators and targets register themselves with iSNS server
o Initiator may query iSNS server for a list of available targets
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 377
iSCSI Lesson
iSNS Discovery Domain
iSNS discovery domains function in the same way as FC zones. Discovery
domains provide functional groupings of devices (including iSCSI initiators and
targets) in an IP SAN. The iSNS server is configured with discovery domains.
For devices to communicate with one another, they must be configured in the same
discovery domain. The iSNS server may send state change notifications (SCNs) to
the registered devices. State change notifications inform the registered devices
about network events. These events affect the operational state of devices such as
the addition or removal of devices from a discovery domain.
Discovery Domains
Discovery Domains
iSCSI initiator
iSCSI initiator
VM
VM
VM
Hypervisor
VM
VM
VM
Hypervisor
Hypervisor
iSNS
iSCSI Target
Queries and Notifications
iSCSI Target
Information Storage and Management (ISM) v4
Page 378
© Copyright 2019 Dell Inc.
iSCSI Lesson
Virtual LAN (VLAN)
Definition: VLAN
A logical network created on a LAN enabling communication between
a group of nodes with a common set of functional requirements,
independent of their physical location in the network.
Well-suited for iSCSI deployments as they enable isolating the iSCSI traffic from
other network traffic (for example, compute-to-compute traffic).
Help in isolating specific network traffic from other network traffic in a physical
Ethernet network
Configuring a VLAN:

Define VLANs on switches with specific VLAN IDs

Configure VLAN membership based on a supported technique
 Port-based
 MAC-based
 Protocol-based
 IP subnet address-based
 Application-based
Notes
A VLAN conceptually functions in the same way as a VSAN. Each VLAN behaves
and is managed as an independent LAN. Two nodes connected to a VLAN can
communicate between themselves without routing of frames – even if they are in
different physical locations. VLAN traffic must be forwarded through a router or OSI
Layer-3 switching device when two nodes in different VLANs are communicating –
even if they are connected to the same physical LAN. Network broadcasts within a
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 379
iSCSI Lesson
VLAN generally do not propagate to nodes that belong to a different VLAN, unless
configured to cross a VLAN boundary.
To configure VLANs, an administrator first defines the VLANs on the switches.
Each VLAN is identified by a unique 12-bit VLAN ID (as per IEEE 802.1Q
standard). The next step is to configure the VLAN membership based on an
appropriate technique supported by the switches. The switches can be port-based,
MAC-based, protocol-based, IP subnet address-based, and application-based. In
the port-based technique, membership in a VLAN is defined by assigning a VLAN
ID to a switch port. When a node connects to a switch port that belongs to a VLAN,
the node becomes a member of that VLAN.
In the MAC-based technique, the membership in a VLAN is defined by the MAC
address of the node. In the protocol-based technique, different VLANs are
assigned to different protocols based on the protocol type field found in the OSI
Layer 2 header. In the IP subnet address-based technique, the VLAN membership
is based on the IP subnet address. All the nodes in an IP subnet are members of
the same VLAN. In the application-based technique, a specific application, for
example, a file transfer protocol (FTP) application can be configured to execute on
one VLAN. A detailed discussion on these VLAN configuration techniques is
beyond the scope of this course.
Information Storage and Management (ISM) v4
Page 380
© Copyright 2019 Dell Inc.
iSCSI Lesson
VLAN Trunking and Tagging

VLAN trunking allows a single network link (trunk link) to carry multiple VLAN
traffic

To enable trunking, trunk ports must be configured on both sending and
receiving network components

Sending network component inserts a tag field containing VLAN ID into an
Ethernet frame before sending through a trunk link

Receiving network component reads the tag and forwards the frame to
destination port(s)
 Tag is removed once a frame leaves trunk link to reach a node port
Notes
Similar to the VSAN trunking, network traffic from multiple VLANs may traverse a
trunk link. A single network port, called trunk port, is used for sending or receiving
traffic from multiple VLANs over a trunk link. Both the sending and the receiving
network components must have at least one trunk port configured for all or a
subset of the VLANs defined on the network component.
As with VSAN tagging, VLAN has its own tagging mechanism. The tagging is
performed by inserting a 4-byte tag field containing 12-bit VLAN ID into the
Ethernet frame (as per IEEE 802.1Q standard) before it is transmitted through a
trunk link. The receiving network component reads the tag and forwards the frame
to the destination port(s) that corresponds to that VLAN ID. The tag is removed
once the frame leaves a trunk link to reach a node port.
IEEE 802.1ad Multi-tagging: IEEE 802.1ad is an amendment to IEEE 802.1Q and
enables inserting multiple VLAN tags to an Ethernet frame. IEEE 802.1Q mandates
a single tag with a 12-bit VLAN ID field, which limits the number of VLANs in an
environment theoretically up to 4096. In a large environment such as a cloud
infrastructure, this limitation may restrict VLAN scalability. IEEE 802.1ad provides
the flexibility to accommodate a larger number of VLANs. For example, by using a
double-tag, theoretically 16777216 (4096×4096 ) VLANs may be configured.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 381
iSCSI Lesson
Information Storage and Management (ISM) v4
Page 382
© Copyright 2019 Dell Inc.
iSCSI Lesson
Stretched VLAN
Definition: Stretched VLAN
A VLAN that spans multiple sites and enables OSI Layer 2
communication between a group of nodes over an OSI Layer 3 WAN
infrastructure, independent of their physical location.
Site 1
Site 2
VLAN 10
VLAN 20
VLAN 10
VLAN 10
Compute System
Compute System
VLAN 20
VLAN 20
VM
VM
Hypervisor
VM
VM
VM
VM
Hypervisor
Hypervisor
VM
VM
VM
VM
Hypervisor
Hypervisor
VLAN 20
Compute System
VM
VM
VM
Hypervisor
VM
VM
Hypervisor
Ethernet
Switch
WAN
Ethernet Director
VM
Hypervisor
VLAN 10 and 20 Traffic
Ethernet
Switch
Storage System
VLAN 10
Compute System
Ethernet Director
Storage System
Storage System
Storage System
Notes
In a typical multisite environment, network traffic between sites is routed through an
OSI Layer 3 WAN connection. Because of the routing, it is not possible to transmit
OSI Layer 2 traffic between the nodes in two sites. A stretched VLAN extends a
VLAN across the sites. It also enables nodes in two different sites to communicate
over a WAN as if connected to the same network.
Stretched VLANs also enable the movement of virtual machines (VMs) between
sites without the need to change their network configurations. This simplifies the
creation of high-availability clusters, VM migration, and application and workload
mobility across sites. The clustering across sites, for example, enables moving
VMs to an alternate site in the event of a disaster or during the maintenance of one
site. Without a stretched VLAN, the IP addresses of the VMs must be changed to
match the addressing scheme at the other site.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 383
iSCSI Lesson
Information Storage and Management (ISM) v4
Page 384
© Copyright 2019 Dell Inc.
iSCSI Lesson
Advantages of IP SAN in Modern Data Center
Advances in IP-based networked storage technology such as IP SAN have created
an opportunity for organizations of all sizes to cost-effectively build, manage, and
maintain their data center. In comparison to internal server storage or DAS, it
efficiently handles the complexity of the modern data center by using existing IP
networks and components.
In a data center IP SAN offers multiple advantages which are common to midsize
businesses, including the following:
Increased
utilization
Consolidated IP-based storage enables servers to access
and share storage, helping maximize utilization of these
resources
Reduced
management costs
Consolidated storage enables centralized management,
helping simplify administrative tasks and reduce management
costs
Increased reliability A shared set of dedicated IP-based storage systems can help
significantly increase the reliability and availability of
application data
Simplified backup
and recovery
IP SAN enables administrators to easily implement
consistent, common, and simple backup and recovery
processes
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 385
FCIP Lesson
FCIP Lesson
Introduction
This lesson covers FCIP connectivity, FCIP tunnel configuration, and FCIP protocol
stack.
This lesson covers the following topics:

FCIP connectivity

FCIP tunnel configuration

FCIP protocol stack
Information Storage and Management (ISM) v4
Page 386
© Copyright 2019 Dell Inc.
FCIP Lesson
FCIP
Video: FCIP
The video is located at
https://edutube.emc.com/Player.aspx?vno=TXNVxHBRJHNl2rK3Su0SZw
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 387
FCIP Lesson
FCIP Overview
FC SAN provides a high-performance infrastructure for localized data movement. It
also:

Provides IP-based protocol that is used to interconnect distributed FC SAN
islands over an IP network

Encapsulates FC frames onto IP packet and transports over existing IP network

Enables transmission by tunneling data between FC SAN islands

Provides disaster recovery solution by enabling replication of FC data across an
IP network

Facilitates data sharing and data collaboration from worldwide locations
Information Storage and Management (ISM) v4
Page 388
© Copyright 2019 Dell Inc.
FCIP Lesson
FCIP Connectivity
Compute Systems
Compute Systems
VM
VM
VM
VM
VM
VM
VM
VM
APP
APP
APP
APP
APP
APP
APP
APP
OS
OS
OS
OS
OS
OS
OS
OS
Hypervisor
Hypervisor
Hypervisor
Hypervisor
FC SAN
FC SAN
FCIP Tunnel
FCIP Gateway
LAN/WAN
FCIP Gateway
Storage System
Storage System

FCIP entity (e.g. FCIP gateway) is connected to each fabric to enable tunneling
through an IP network

An FCIP tunnel consists of one or more independent connections between two
FCIP ports
 Transports encapsulated FC frames over TCI/IP
Notes
In an FCIP environment, FCIP entity such as an FCIP gateway is connected to
each fabric through a standard FC connection. The FCIP gateway at one end of the
IP network encapsulates the FC frames into IP packets. The gateway at the other
end removes the IP wrapper and sends the FC data to the adjoined fabric. The
fabric treats these gateways as fabric switches. An IP address is assigned to the
port on the gateway, which is connected to an IP network. After the IP connectivity
is established, the nodes in the two independent fabrics can communicate with
other.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 389
FCIP Lesson
An FCIP tunnel consists of one or more independent connections between two
FCIP ports on gateways (tunnel endpoints). Each tunnel transports encapsulated
FC frames over a TCP/IP network. The nodes in either fabric are unaware of the
existence of the tunnel. Multiple tunnels may be configured between the fabrics
based on connectivity requirement. Some implementations enable aggregating
FCIP links (tunnels) to increase throughput and to provide link redundancy and
load balancing.
Information Storage and Management (ISM) v4
Page 390
© Copyright 2019 Dell Inc.
FCIP Lesson
FCIP Tunnel Configuration - Merged Fabric
An FCIP tunnel may be configured to merge interconnected fabrics into a single
large fabric. In the merged fabric, FCIP transports existing fabric services across
the IP network.
The image illustrates a merged fabric deployment. In this deployment:

The E_Port on an FCIP gateway connects to the E_Port of an FC switch in the
adjoined fabric

The FCIP gateway is also configured with a VE_port that behaves like an
E_Port, except that the VE_Port is used to transport data through an FCIP
tunnel

The FCIP tunnel has VE_Ports on both ends

The VE_Ports establish virtual ISLs through the FCIP tunnel, which enable
fabrics on either side of the tunnel to merge
E
VE
E
FCIP Tunnel
LAN/WAN
FC SAN
FCIP Gateway
V
E
FCIP Gateway
E
FC SAN
Storage System
Storage System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 391
FCIP Lesson
FCIP Tunnel Configuration – Separate Fabric
Only a small subset of nodes in either fabric requires connectivity across an FCIP
tunnel. Thus, an FCIP tunnel may also use vendor-specific features to route
network traffic between specific nodes without merging the fabrics.
The image illustrates a solution for FC-FC routing but the FCIP tunnel is configured
in a way that does not merge the fabrics. In this deployment:

Ex_Port and VE_Port are configured on each FCIP gateway

The EX_Port on the FCIP gateway connects to an E_Port on an FC switch in
the adjoined fabric

The EX_Port functions similarly to an E_Port, but does not propagate fabric
services from one fabric to another

The EX_Port enables FC-FC routing through the FCIP tunnel, but the fabrics
remain separate
E
FC SAN
E
X
V
FCIP Gateway
FCIP Tunnel
LAN/WAN
V
FCIP Gateway
Storage System
E
X
E
FC SAN
Storage System
Information Storage and Management (ISM) v4
Page 392
© Copyright 2019 Dell Inc.
FCIP Lesson
FCIP Protocol Stack
Protocol Stack
The FCIP protocol stack is shown on the image.

Applications generate SCSI commands and data, which are processed by
various layers of the protocol stack

The upper layer protocol SCSI includes the SCSI driver program that executes
the read-and-write commands

Below the SCSI layer is the FC protocol (FCP) layer, which is simply an FC
frame whose payload is SCSI

The FC frames can be encapsulated into the IP packet and sent to a remote FC
SAN over the IP

The FCIP layer encapsulates the FC frames onto the IP payload and passes
them to the TCP layer

TCP and IP are used for transporting the encapsulated information across
Ethernet, wireless, or other media that support the TCP/IP traffic
Application
SCSI Commands, Data, and Status
Encapsulation
FC Frame
FCP (SCSI over FC)
FCIP
TCP
IP
Physical Media
FC to IP Encapsulation
Encapsulation of FC frame on to
IP packet could cause the IP
packet to be fragmented. The
fragmentation occurs when the
data link cannot support the
maximum transmission unit (MTU)
size of an IP packet.

When an IP packet
is fragmented, the required parts of the header must be copied by all fragments
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 393
FCIP Lesson
FC Frame
SOF
FC Header
SCSI Data
CRC
EOF
FCIP Encapsulation
IP Header
TCP Header
FCIP Header
IP Payload
IP Packet

When a TCP packet is segmented, normal TCP operations are responsible for
receiving and resequencing the data

The receiving and resequencing is performed prior to passing it on to the FC
processing portion of the device
Information Storage and Management (ISM) v4
Page 394
© Copyright 2019 Dell Inc.
FCoE Lesson
FCoE Lesson
Introduction
This lesson focuses on FCoE components and FCoE connectivity.It also covers
FCoE switch and CNA.
This lesson covers the following topics:

FCoE components and connectivity

FCoE switch and CNA
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 395
FCoE Lesson
FCoE
Video: FCoE
The video is located at
https://edutube.emc.com/Player.aspx?vno=g+QJTBgku2x0CRTtmGqyow
Information Storage and Management (ISM) v4
Page 396
© Copyright 2019 Dell Inc.
FCoE Lesson
FCoE Overview

A protocol that transports FC data along with regular Ethernet traffic over a
Converged Enhanced Ethernet (CEE) network

Uses FCoE protocol, defined by the T11 standards committee, that
encapsulates FC frames into Ethernet frames

Ensures lossless transmission of FC traffic over Ethernet
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 397
FCoE Lesson
Drivers for FCoE

Multi-function network components are used to transfer both compute-tocompute and FC storage traffic
– Reduce the complexity of managing multiple discrete networks
– Reduce the number of network adapters, cables, and switches required in a
data center
– Reduce power and space consumption in a data center
Information Storage and Management (ISM) v4
Page 398
© Copyright 2019 Dell Inc.
FCoE Lesson
Components of FCoE
The key FCoE components are:

Network adapters
 Example: Converged Network Adapter (CNA) and software FCoE adapter

Cables
 Example: Copper cables and fiber optical cables

FCoE switch
Compute Systems
VM
VM
VM
Hypervisor
VM
Hypervisor
VM
VM
Hypervisor
CNA
CEE Link
LAN
FCoE Switch
FC
SAN
FC Ports
Storage Systems
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 399
FCoE Lesson
What is CNA?
10GE/FCoE
FCoE ASIC
10GE
FC
ASIC
ASIC
PCIe Bus

A physical adapter that provides functionality of both NIC and FC HBA

Encapsulates FC frames into Ethernet frames and forwards them over CEE
links

Contains separate modules for 10 GE, FC, and FCoE ASICs
Information Storage and Management (ISM) v4
Page 400
© Copyright 2019 Dell Inc.
FCoE Lesson
FCoE Switch
An FCoE switch has both Ethernet switch and FC switch functionalities. It has a
Fibre Channel Forwarder (FCF), an Ethernet Bridge, and a set of ports that can be
used for FC and Ethernet connectivity:
FC Port
FC Port
FC Port
FC Port
Fibre Channel Forwarder (FCF)
Ethernet Bridge
Ethernet Port

Ethernet Port
Ethernet Port
Ethernet Port
FCF functions as the communication bridge between CEE and FC networks
 Encapsulates and decapsulates FC frames

FCoE switch inspects the Ethertype and forwards to the appropriate destination
 FCoE frames contain an FC payload are forwarded to the FCF
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 401
FCoE Lesson
 Non FCoE frames are handled as typical Ethernet traffic and forwarded over
the Ethernet ports
Information Storage and Management (ISM) v4
Page 402
© Copyright 2019 Dell Inc.
FCoE Lesson
FCoE SAN Connectivity
The most common FCoE connectivity uses FCoE switches

To interconnect a CEE network containing compute systems with an FC SAN
containing storage systems

FCoE switches enable the consolidation of FC traffic and Ethernet traffic onto
CEE links
This type of FCoE connectivity is suitable when an organization has an existing FC
SAN environment. Connecting FCoE compute systems to the FC storage systems
through FCoE switches do not require any change in the FC environment.
VM
VM
FCoE Switch
FCoE Port
Hypervisor
Compute Systems with
CNA
LAN
VM
VM
FC SAN
FC Ports
Hypervisor
FCoE Switch
Storage System
CEE Link
Notes
This type of FCoE connectivity is suitable when an organization has an existing FC
SAN environment. Connecting FCoE compute systems to the FC storage systems
through FCoE switches do not require any change in the FC environment.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 403
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell PowerConnect B-8000 Network Switch

Dell EMC Networking S-Series 10GbE switches

Dell Networking Z-Series core/aggregation switches

Dell EMC S4148U
Information Storage and Management (ISM) v4
Page 404
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts In Practice
Concepts in Practice
Dell PowerConnect B-8000 Network Switch

Provides a unified FCoE Solution

Supports 10-GbE and FC ports

Supports comprehensive Layer 2 LAN capabilities with high Performance and
availability

Provides a versatile solution for Server I/O Consolidation
Dell EMC Networking S-Series 10GbE switches

Provides high performance open networking top-of-rack switches

Provides support for iSCSI storage area networks

Provides flexibility and is cost effective

Flexible, powerful 10-GbE ToR switches for data centers of all sizes
Dell Networking Z-Series core/aggregation switches

Provides optimal flexibility, performance, density, and power efficiency

Includes 10/25/40/50/100GbE options
Dell EMC S4148U

Offers various port speed choices for Fibre Channel and Ethernet connectivity

Provides flexibility and high performance for modern workloads

Can be used in the following use cases:
 Provide end to end FC switch connectivity
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 405
Concepts in Practice Lesson
 NPIV Gateway Edge switch in large multi-vendor SAN environments

Supports up to 32 Gbps FC and 100 GbE Ethernet connectivity
Dell PowerConnect B-8000 Network Switch
A top-of-rack link layer CEE/DCB and FCoE switch. It comprises of 24 10-Gigabit
Ethernet ports for LAN connections and 8 Fibre Channel ports with up to 8-Gigabit
speed for Fibre Channel SAN connections. The network switch supports
comprehensive Layer 2 LAN capabilities and, provide high performance and
availability. The functionality of server I/O Consolidation is too supported by the
Power Connect B-8000 Network Switch.
Dell EMC Networking S-Series 10GbE switches
A high-performance open networking top-of-rack switches with multirate Gigabit
Ethernet and unified ports. It offers flexibility and cost-effectiveness for the
enterprise, and Tier2 cloud service provider with demanding compute and storage
traffic environments. The switches support iSCSI and FC storage deployment,
including DCB converged lossless transactions. It comprises of 10GbE S4000-ON
Series switches, 1/10G BASE-T S4048T-ON, S4128T-ON, and S4148T-ON
switches. Dell EMC Networking S-Series 10GbE switches offers active fabric
designs using S- or Z-Series core switches to create a two-tier 1/20/40/100-GbE
data center network.
Dell Networking Z-Series core/aggregation switches
Open networking and SDN-ready fixed form factor switches. They are purpose-built
for applications in modern computing environments. They not only simplify
manageability, it provides optimal flexibility, performance, density and power
efficiency for the data center. It also supports both VLAN Tagging and Double
VLAN Tagging and comprises of 10/25/40/50/100GbE options.
Dell EMC S4148U
A feature rich multi-functional switch offering various port speed choices for Fibre
Channel and Ethernet connectivity. It is designed for flexibility and high
performance for today’s demanding modern workloads and performance. It can be
used as an end to end FC switch and as an NPIV Gateway Edge switch in a large
Information Storage and Management (ISM) v4
Page 406
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
multi-vendor SAN environment. It supports up to 32 Gbps FC and 100 GbE
Ethernet connectivity.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 407
Concepts in Practice Lesson
Assessment
1. Which of the following function is supported by the ICMP (Internet Control
Message Protocol)
A. Handles error and control message
B. Flow Control
C. Monitors Computers
D. Buffers packet
2. Which protocol is used by IP SAN for the transport of block-level data?
A. iSCSI
B. ARP
C. ICMP
D. Ethernet
Information Storage and Management (ISM) v4
Page 408
© Copyright 2019 Dell Inc.
Summary
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 409
File-Based and Object-Based Storage System
Introduction
This module focuses on the NAS components and architecture. This module also
focuses on object-based storage components and operations. Finally, this module
focuses on unified storage architecture.
Upon completing this module, you will be able to:
 Describe NAS components and architecture
 Describe object-based storage components and operations
 Describe unified storage architecture
Information Storage and Management (ISM) v4
Page 410
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
NAS Components and Architecture Lesson
Introduction
This lesson focuses on the components and architectures of a file-based storage
system. This module also focuses on various file access methods supported by a
file-based storage system. Finally, this module focuses on NAS I/O operations.
This lesson covers the following topics:

Describe NAS components and architectures

Discuss NAS file access methods

Discuss NAS I/O operations
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 411
NAS Components and Architecture Lesson
NAS Components and Architecture
Video: NAS Components and Architecture
The video is located at
https://edutube.emc.com/Player.aspx?vno=eRMzm7xSHuP3ffzyGz0mQQ
Information Storage and Management (ISM) v4
Page 412
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
File Sharing Environment

File sharing enables users to share files with other users

File sharing environment ensures data integrity when multiple users access a
shared file simultaneously

Examples of file sharing methods
– File Transfer Protocol (FTP)
– Peer-to-Peer (P2P)
– Network File System (NFS) and Common Internet File System (CIFS)
– Distributed File System (DFS)
Notes
In a file-sharing environment, a user who creates the file (the creator or owner of a
file) determines the type of access (such as read, write, execute, append, delete) to
be given to other users. When multiple users try to access a shared file
simultaneously, a locking scheme is required to maintain data integrity and
simultaneously make this sharing possible.
Some examples of file-sharing methods are the peer-to-peer (P2P) model, File
Transfer Protocol (FTP), client/server models that use file-sharing protocols such
as NFS and CIFS, and Distributed File System (DFS). FTP is a client/server
protocol that enables data transfer over a network. An FTP server and an FTP
client communicate with each other using TCP as the transport protocol.
A peer-to-peer (P2P) file sharing model uses peer-to-peer network. P2P enables
client machines to directly share files with each other over a network. Clients use a
file sharing software that searches for other peer clients. This software differs from
client/server model that uses file servers to store files for sharing.
The standard client/server file-sharing protocols are NFS and CIFS. These
protocols enable the owner of a file to set the required type of access, such as
read-only or read/write, for a particular user or group of users. Using this protocol,
the clients mount remote file systems that are available on dedicated file servers.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 413
NAS Components and Architecture Lesson
A distributed file system (DFS) is a file system that is distributed across several
compute systems. A DFS can provide compute systems with direct access to the
entire file system, while ensuring efficient management and data security. Hadoop
Distributed File System (HDFS) is an example of distributed file system which is
later discussed in this module. Vendors now support HDFS on their NAS systems
to support the scale-out architecture. The scale-out architecture helps to meet the
big data analytics requirements.
Information Storage and Management (ISM) v4
Page 414
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
What is NAS?
Definition: NAS
An IP-based, dedicated, high-performance file sharing and storage
device.

Enables NAS clients to share files over IP network

Uses specialized operating system that is optimized for file I/O

Enables both UNIX and Windows users to share data
Clients
LAN
VM
VM
NAS System
Hypervisor
Application Servers
Notes
NAS provides the advantages of server consolidation by eliminating the need for
multiple file servers. It also consolidates the storage used by the clients onto a
single system, making it easier to manage the storage. NAS uses network and filesharing protocols to provide access to the file data. These protocols include TCP/IP
for data transfer and Common Internet File System (CIFS) and Network File
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 415
NAS Components and Architecture Lesson
System (NFS) for network file service. Apart from these protocols, the NAS
systems may also use HDFS and its associated protocols (discussed later in the
module) over TCP/IP to access files. NAS enables both UNIX and Microsoft
Windows users to share the same data seamlessly.
A NAS device uses its own operating system and integrated hardware and
software components to meet specific file-service needs. Its operating system is
optimized for file I/O and, therefore, performs file I/O better than a general-purpose
server. As a result, a NAS device can serve more clients than general-purpose
servers and provide the benefit of server consolidation.
Information Storage and Management (ISM) v4
Page 416
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
General Purpose Servers Vs. NAS Devices

A general-purpose server can be used to host any application because it runs a
general-purpose operating system

Unlike a general-purpose server, a NAS device is dedicated to file-serving

It has a specialized operating system dedicated for file serving by using industry
standard protocols. NAS vendors also support features, such as clustering for
high availability, scalability, and performance

The clustering feature enables multiple NAS controllers/heads/nodes to function
as a single entity. The workload can be distributed across all the available
nodes. Therefore, NAS devices support massive workloads
Applications
Print Drivers
File System
File System
Operating System
Operating System
Network Interface
Network Interface
General Purpose Server
NAS System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 417
NAS Components and Architecture Lesson
Components of NAS System

Controller/NAS head consists of
 CPU, memory, network adapter, and so on
 Specialized operating systems installed

Storage
 Supports different types of storage devices

Scalability of the components depends on NAS architecture
 Scale-up NAS
 Scale-out NAS
Notes
A NAS system consists of two components, controller and storage. A controller is a
compute system that contains components such as network, memory, and CPU
resources. A specialized operating system optimized for file serving is installed on
the controller. Each controller may connect to all storage in the system. The
controllers can be active/active, with all controllers accessing the storage, or
active/passive with some controllers performing all the I/O processing while others
act as spares. A spare is used for I/O processing if an active controller fails. The
controller is responsible for configuration of RAID set, creating LUNs, installing file
system, and exporting the file share on the network.
Storage is used to persistently store data. The NAS system may have different
types of storage devices to support different requirements. The NAS system may
support SSD, SAS, and SATA in a single system.
The extent to which the components, such as CPU, memory, network adapters,
and storage, can be scaled depends upon the type of NAS architecture used.
There are two types of NAS architectures; scale-up and scale-out. Both these
architectures are detailed in the next few slides.
Information Storage and Management (ISM) v4
Page 418
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Scale-Up NAS
Storage
NAS Head(s)
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 419
NAS Components and Architecture Lesson
A scale-up NAS architecture provides the capability to scale the capacity and
performance of a single NAS system based on requirements. Scaling up a NAS
system involves upgrading or adding NAS heads and storage.
These NAS systems have a fixed capacity ceiling, which limits their scalability. The
performance of these systems starts degrading when reaching the capacity limit.
Information Storage and Management (ISM) v4
Page 420
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Scale-Up NAS Implementations
There are two types of scale-up NAS implementations:
Unified NAS
A unified NAS system contains one or more NAS heads and storage in a single
system. NAS heads are connected to the storage. The storage may consist of
different drive types, such as SAS, ATA, FC, and solid-state drives, to meet
different workload requirements.
Each NAS head in a unified NAS has front-end Ethernet ports, which connect to
the IP network. The front-end ports provide connectivity to the clients. Each NAS
head has back-end ports to provide connectivity to the attached storage. Unified
NAS systems have NAS management software that can be used to perform all the
administrative tasks for the NAS head and storage.
VM
VM
Block Data
Access
FC SAN
Hypervisor
FC Host
FC Port
VM
VM
Block Data
Access
iSCSI SAN
Hypervisor
iSCSI Port
Ethernet Port
iSCSI Host
Unified NAS
Ethernet
File Data
Access
NAS Clients
Unified NAS
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 421
NAS Components and Architecture Lesson
Gateway NAS
A gateway NAS system consists of one or more NAS heads and uses external and
independently managed storage. In gateway NAS implementation, the NAS
gateway shares the storage from a block-based storage system. The management
functions in this type of solution are more complex than those in an integrated a
unified NAS environment. This is because there are separate administrative tasks
for the NAS head and the storage.
The administrative tasks of the NAS gateway are performed by the NAS
management software. The storage system is managed with the management
software of the block-based storage system. A gateway solution can use the FC
infrastructure, such as switches and directors for accessing SAN-attached storage
arrays or direct-attached storage arrays.
VM
VM
Hypervisor
NAS Clients
Application Server
VM
VM
FC SAN
IP
Hypervisor
NAS Clients
Application Server
Storage System
NAS Gateway
NAS Clients
Gateway NAS
Information Storage and Management (ISM) v4
Page 422
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Scale-Out NAS
External Switch
Node1
Storage
Node2
Storage
Node3
Storage
Cluster
Controller
Controller
Internal InfiniBand
Switch1
Controller
Internal InfiniBand
Switch2

Pools multiple nodes in a cluster to work as a single NAS device

Scales performance and/or capacity non-disruptively

Creates a single file system that runs on all nodes in the cluster
 File system grows dynamically as nodes are added

Stripes data across nodes with mirror or parity protection
Notes
The scale-out NAS implementation pools multiple NAS nodes together in a cluster.
A node may consist of either the NAS head or the storage or both. The cluster
performs the NAS operation as a single entity. A scale-out NAS provides the
capability to scale its resources by simply adding nodes to a clustered NAS
architecture. The cluster works as a single NAS device and is managed centrally.
Nodes can be added to the cluster, when more performance or more capacity is
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 423
NAS Components and Architecture Lesson
needed, without causing any downtime. Scale-out NAS provides the flexibility to
use many nodes of moderate performance and the availability characteristics. This
scale-out NAS produce a total system that has better aggregate performance and
availability. It also provides ease of use, low cost, and theoretically unlimited
scalability.
Scale-out NAS uses a distributed clustered file system that runs on all nodes in the
cluster. All information is shared among nodes, so the entire file system is
accessible by clients connecting to any node in the cluster. Scale-out NAS stripes
data across all nodes in a cluster along with mirror or parity protection. As data is
sent from clients to the cluster, the data is divided and allocated to different nodes
in parallel. When a client sends a request to read a file, the scale-out NAS retrieves
the appropriate blocks from multiple nodes. It recombines the blocks into a file and
presents the file to the client. As nodes are added, the file system grows
dynamically, and data is evenly distributed to every node. Each node added to the
cluster increases the aggregate storage, memory, CPU, and network capacity.
Hence, cluster performance is also increased.
Scale-out NAS clusters use separate internal and external networks for back-end
and front-end connectivity respectively. An internal network provides connections
for intra-cluster communication, and an external network connection enables clients
to access and share file data. Each node in the cluster connects to the internal
network. The internal network offers high throughput and low latency and uses
high-speed networking technology, such as InfiniBand or Gigabit Ethernet. To
enable clients to access a node, the node must be connected to the external
Ethernet network. Redundant internal or external networks may be used for high
availability.
Tip: InfiniBand is a networking technology that provides a low-latency,
high-bandwidth communication link between hosts and peripherals. It
provides serial connection and is often used for inter-server
communications in high-performance computing environments.
InfiniBand enables remote direct memory access (RDMA) that
enables a device (host or peripheral) to access data directly from the
memory of a remote device. InfiniBand also enables a single physical
link to carry multiple channels of data simultaneously by using a
multiplexing technique.
Information Storage and Management (ISM) v4
Page 424
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 425
NAS Components and Architecture Lesson
NAS File Access Methods
Different methods can be used to access files on a NAS system. The most
common methods are:

Common Internet File System / Server Message Block (CIFS/SMB)

Network File System (NFS)

Hadoop Distributed File System (HDFS)
CIFS/SMB

Client-server application protocol
 An open variation of the Server Message Block (SMB) protocol which is
used for Windows file sharing

Enables clients to access files that are on a server over TCP/IP

Stateful Protocol
 Maintains connection information regarding every connected client
 Can automatically restore connections and reopen files that were open prior
to interruption
NFS

Client-server application protocol

Enables clients to access files that are on a server

Uses Remote Procedure Call (RPC) mechanism to provide access to remote
file system
HDFS

A file system that spans multiple nodes in a cluster and enables user data to be
stored in files.
Information Storage and Management (ISM) v4
Page 426
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson

Presents a traditional hierarchical file organization so that users or applications
can manipulate (create, rename, move, or remove) files and directories

Presents a streaming interface to run any application of choice using the
MapReduce framework
Hadoop Cluster
Data Node
Data Node
Data Node
Data Node
Clients
Ethernet
LAN
NameNode
Data Node
Data Node
Data Node
Data Node
Clients
Notes
Common Internet File System (CIFS): is a client/server application protocol that
enables client programs to make requests for files and services on remote
computers over TCP/IP. It is a public or open variation of Server Message Block
(SMB) protocol.
The CIFS protocol enables remote clients to gain access to files on a server. CIFS
enables file sharing with other clients by using special locks. Filenames in CIFS are
encoded using Unicode characters. CIFS provides the following features to ensure
data integrity:

It uses file and record locking to prevent users from overwriting the work of
another user on a file or a record.

It supports fault tolerance and can automatically restore connections and
reopen files that were open prior to an interruption.
The fault tolerance features of CIFS depend on whether an application is written to
take advantage of these features. Moreover, CIFS is a stateful protocol because
the CIFS server maintains connection information regarding every connected client.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 427
NAS Components and Architecture Lesson
If a network failure or CIFS server failure occurs, the client receives a
disconnection notification. User disruption is minimized if the application has the
embedded intelligence to restore the connection. However, if the embedded
intelligence is missing, the user must take steps to reestablish the CIFS
connection.
Users refer to remote file systems with an easy-to-use file-naming scheme:
\\server\share or \\servername.domain.suffix\share.
Network File System (NFS): is a client/server protocol for file sharing that is
commonly used on UNIX systems. NFS was originally based on the connectionless
User Datagram Protocol (UDP). It uses a machine-independent model to represent
user data. It also uses Remote Procedure Call (RPC) for interprocess
communication between two computers.
The NFS protocol provides a set of RPCs to access a remote file system for the
following operations:

Searching files and directories

Opening, reading, writing to, and closing a file

Changing file attributes

Modifying file links and directories
NFS creates a connection between the client and the remote system to transfer
data.
HDFS: is supported by many of the scale-out NAS vendors. HDFS requires
programmatic access because the file system cannot be mounted. All HDFS
communication is layered on top of the TCP/IP protocol. HDFS has a master/slave
architecture. An HDFS cluster consists of a single NameNode that acts as a master
server. This cluster has in-memory maps of every file, file locations as well as all
the blocks within the file and which DataNodes they reside on. The NameNode is
responsible for managing the file system namespace and controlling the access to
the files by clients. DataNodes act as slaves that serve read/write requests and
perform block creation, deletion, and replication as directed by the NameNode.
Information Storage and Management (ISM) v4
Page 428
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Scale-Up NAS I/O Operation
2
Application
Storage Interface
Operating System
NAS Operating System
NFS/CIFS
NFS/CIFS
3
TCP/IP Stack
Block I/O
TCP/IP Stack
1
Network Interface
Network Interface
File I/O
Client
Storage
4
NAS Head
The figure illustrates an I/O operation in a scale-up NAS system. The process of
handling I/Os in a scale-up NAS environment is as follows:
1. The requestor (client) packages an I/O request into TCP/IP and forwards it
through the network stack. The NAS system receives this request from the
network.
2. The NAS system converts the I/O request into an appropriate physical storage
request, which is a block-level I/O. This system then performs the operation on
the physical storage.
3. When the NAS system receives data from the storage, it processes and
repackages the data into an appropriate file protocol response.
4. The NAS system packages this response into TCP/IP again and forwards it to
the client through the network.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 429
NAS Components and Architecture Lesson
Scale-Out NAS I/O Operation
Cluster
NAS
Node
NAS
Node
NAS
Node
Clients
Ethernet
LAN
NAS
Node
NAS
Node
NAS
Node
Clients
The figure illustrates I/O operation in a scale-out NAS system. A scale-out NAS
consists of multiple NAS nodes and each of these nodes has the functionality
similar to a NameNode or a DataNode. In some proprietary scale-out NAS
implementations, each node may function as both a NameNode and DataNode,
typically to provide Hadoop integration. All the NAS nodes in scale-out NAS are
clustered.
Write Operation
Read Operation
1. Client sends a file to the NAS node
1. Client requests a file
2. Node to which the client is connected 2. Node to which the client is connected
receives the file
receives the request
3. File is striped across the nodes
3. The node retrieves and rebuilds the
file and gives it to the client
Information Storage and Management (ISM) v4
Page 430
© Copyright 2019 Dell Inc.
NAS Components and Architecture Lesson
Notes
New nodes can be added as required. As new nodes are added, the file system
grows dynamically and is evenly distributed to each node. As the client sends a file
to store to the NAS system, the file is evenly striped across the nodes. When a
client writes data, even though that client is connected to only one node, the write
operation occurs in multiple nodes in the cluster. This operation is also true for read
operations. A client is connected to only one node at a time. However, when that
client requests a file from the cluster, the node to which the client is connected
don’t have the entire file locally on its drives. The node to which the client is
connected retrieves and rebuilds the file using the back-end InfiniBand network.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 431
File-Level Virtualization and Tiering Lesson
File-Level Virtualization and Tiering Lesson
Introduction
This lesson covers file-level virtualization, storage tiering, and NAS use case.
This lesson covers the following topics:

Explain file-level virtualization

Discuss storage tiering

Discuss NAS use cases
Information Storage and Management (ISM) v4
Page 432
© Copyright 2019 Dell Inc.
File-Level Virtualization and Tiering Lesson
File-Level Virtualization and Tiering
Video: File-level Virtualization and Tiering
The video is located at
https://edutube.emc.com/Player.aspx?vno=DBo/fa0JMAj05Z4rWTktxQ
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 433
File-Level Virtualization and Tiering Lesson
What is File-Level Virtualization?
A network-based file sharing environment is composed of multiple file servers or
NAS devices. It might be required to move the files from one device to another due
to reasons such as cost or performance. File-level virtualization, which is
implemented in NAS or the file server environment, provides a simple, nondisruptive file-mobility solution.

Eliminates dependency between data accessed at the file-level and the location
where the files are physically stored

Enables users to use a logical path, rather than a physical path, to access files

Uses global namespace that maps logical path of file resources to their physical
path

Provides non-disruptive file mobility across file servers or NAS devices
Information Storage and Management (ISM) v4
Page 434
© Copyright 2019 Dell Inc.
File-Level Virtualization and Tiering Lesson
Before and After File-Level Virtualization
Before virtualization, each client knows exactly where its file resources are located.
This environment leads to underutilized storage resources and capacity problems
because files are bound to a specific NAS device or file server. It may be required
to move the files from one server to another because of performance reasons or
when the file server fills up. Moving files across the environment is not easy and
may make files inaccessible during file movement. Moreover, hosts and
applications need to be reconfigured to access the file at the new location. This
operation makes it difficult for storage administrators to improve storage efficiency
while maintaining the required service level.
File-level virtualization simplifies file mobility. It provides user or application
independence from the location where the files are stored. File-level virtualization
facilitates the movement of files across online file servers or NAS devices. It means
that while the files are being moved, clients can access their files non-disruptively.
Clients can also read their files from the old location and write them back to the
new location without realizing that the physical location has changed.
Clients
Clients
Virtualization
Appliance
NAS Head
NAS Head
NAS Head
Storage System
Before File-level Virtualization
NAS Head
Storage System
After File-level Virtualization
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 435
File-Level Virtualization and Tiering Lesson
File-Level Storage Tiering

Moves files from higher tier to lower tier

Storage tiers are defined based on cost, performance, and availability
parameters

Uses policy engine to determine the files that are required to move to the lower
tier

Predominant use of file tiering is archival
Notes
As the unstructured data in the NAS environment grows, organizations deploy a
tiered storage environment. This environment optimizes the primary storage for
performance and the secondary storage for capacity and cost.
Storage tiering works on the principle of Hierarchical Storage Management (HSM).
HSM is a file mobility concept where a policy-engine, which can be software or
hardware. When these policies are configured, facilitates moving files from the
primary tiered storage to the secondary tiered storage that meets the predefined
policies. In HSM, a hierarchy of storage tier is defined based on parameters such
as cost, performance, and/or availability of storage. Some prevalent reasons to tier
data across storage systems or between storage system and cloud is archival or to
meet compliance requirements.
As an example, the policy engine might be configured to relocate all the files in the
primary storage tier that have not been accessed in one month and archive those
files to the secondary storage. For each archived file, the policy engine creates a
small space-saving stub file in the primary storage that points to the data on the
secondary storage. When a user tries to access the file from its original location on
the primary storage, the user is transparently provided with the actual file from the
secondary storage.
Information Storage and Management (ISM) v4
Page 436
© Copyright 2019 Dell Inc.
File-Level Virtualization and Tiering Lesson
Inter-array Tiering and Cloud Tiering
The figure illustrates the file-level storage tiering. In a file-level storage tiering
environment, a file can be moved to a secondary storage tier or to the cloud.
Before moving a file from primary NAS to secondary NAS or from primary NAS to
cloud, the policy engine scans the primary NAS to identify files that meet the
predefined policies. After identifying the data files, the stub files are created, and
the data files are moved to the destination storage tier.
Cloud Storage Tier
2/Tier 3
3. File is stored in Tier 2/Tier 3
storage
VM
VM
LAN/WAN
Hypervisor
Secondary NAS
Tier2
Application Servers
2.Creates a stub file on
primary NAS system
1. The policy engine scans the
primary NAS system
Policy Engine
Primary NAS
Tier1
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 437
File-Level Virtualization and Tiering Lesson
Use-Case for Scale-Out NAS: Data Lake
The data lake represents a paradigm shift from the linear data flow model. As data
and the insights gathered from it increase in value, the enterprise-wide
consolidated storage is transformed into a hub around which the ingestion and
consumption systems work (see figure). This enables enterprises to bring analytics
to data and avoid expensive cost of multiple systems, storage, and time for
ingestion and analysis.
Ingest
Store
Velocity
Analyse
Data Lake
Sources
Variety
Surface
Volume
Act
Scale-out NAS
The key characteristics of a scale-out data lake are that it:

Accepts data from various sources like file shares, archives, web applications,
devices, and the cloud, in both streaming and batch processes

Enables access to this data for a variety of uses from conventional purpose to
mobile, analytics, and cloud applications

Scales to meet the demands of future consolidation and growth as technology
evolves; new possibilities emerge for applying data to gain competitive
advantage in the market place

Provides a tiering ability that enables organizations to manage their costs
without setting up specialized infrastructures for cost optimization
Information Storage and Management (ISM) v4
Page 438
© Copyright 2019 Dell Inc.
File-Level Virtualization and Tiering Lesson
Notes
By eliminating a number of parallel linear data flows. The enterprises can
consolidate vast amounts of their data into a single store, a data lake, through a
native and simple ingestion process. Analytics can be performed on this data which
provides insight. Actions can be taken based on this insight in an iterative manner,
as the organization and technology mature. Enterprises can thus eliminate the cost
of having silos or islands of information spread across their enterprises.
Scale-out NAS has the ability to provide the storage platform to this data lake. The
scale-out NAS enhances this paradigm by providing scaling capabilities in terms of
capacity, performance, security, and protection.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 439
Object-Based and Unified Storage Lesson
Object-Based and Unified Storage Lesson
Introduction
This lesson focuses on the key object-based storage components. This lesson also
focuses on the key features of object-based storage. Finally, this lesson focuses on
unified storage architecture.
This lesson covers the following topics:

Describe the key components of object-based storage

Explain the key features of object-based storage

Describe unified storage architecture
Information Storage and Management (ISM) v4
Page 440
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Object-Based and Unified Storage Overview
Drivers for Object-Based Storage

Amount of data created annually is growing exponentially and more than 90% of
data generated is unstructured
 Rapid adoption of third platform technologies leads to significant growth of
data
 Longer data retention due to regulatory compliance also leads to data
growth

Data must be instantly accessible through a variety of devices from anywhere in
the world

Traditional storage solutions are inefficient in managing this data and in
handling the growth
Notes
The amount of data created each year is growing exponentially and the recent
studies have shown that more than 90 percent of data generated is unstructured
(e-mail, instant messages, graphics, images, and videos). Today, organizations not
only have to store and protect petabytes of data, but they also have to retain the
data over longer periods of time, for regulation and compliance reasons. They have
also recognized that data can help gain competitive advantages and even support
new revenue streams. In addition to increasing amounts of data, there has also
been a significant shift in how people want and expect to access their data. The
rising adoption rate of smartphones, tablets, and other mobile devices by
consumers, combined with increasing acceptance of these devices in enterprise
workplaces, has resulted in an expectation for on-demand access to data from
anywhere on any device.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 441
Object-Based and Unified Storage Lesson
Traditional storage solutions like NAS, which is a dominant solution for storing
unstructured data, cannot scale to the capacities required or provide universal
access across geographically dispersed locations. Data growth adds high overhead
to the NAS in terms of managing large number of permission and nested
directories. File systems require more management as they scale and are limited in
size. Their performance degrades as file system size increases, and do not
accommodate metadata beyond file properties which is a requirement of many new
applications.These challenges demand a smarter approach (object storage) that
allows to manage data growth at low cost, provides extensive metadata
capabilities, and also provides massive scalability to keep up with the rapidly
growing data storage and access demands.
Information Storage and Management (ISM) v4
Page 442
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Object-Based Storage Device (OSD)
Stores data in the form of objects on flat address space based on its
content and attributes rather than the name and location.
Ds
Metadata
Object
Object ID
Object

Definition: Object-Based Storage Device
– Stores data in the form of objects on flat address space based on its content
and attributes rather than the name and location

Object contains user data, related metadata, and user-defined attributes
 Objects are uniquely identified using object ID

OSD provides APIs to integrate with software-defined data center and cloud
Notes
An object is the fundamental unit of object-based storage that contains user data,
related metadata (size, date, ownership, etc.), and user defined attributes of data
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 443
Object-Based and Unified Storage Lesson
(retention, access pattern, and other business-relevant attributes). The additional
metadata or attributes enable optimized search, retention and deletion of objects.
For example, when an MRI scan of a patient is stored as a file in a NAS system,
the metadata is basic and may include information such as file name, date of
creation, owner, and file type. When stored as an object, the metadata component
of the object may include additional information such as patient name, ID, and
attending physician’s name, apart from the basic metadata.
Each object stored in the object-based storage system is identified by a unique
identifier called the object ID. The object ID allows easy access to objects without
the need to specify the storage location. The object ID is generated using
specialized algorithms (such as a hash function) on the data and guarantees that
every object is uniquely identified. Any changes in the object, like user-based edits
to the file, results in a new object ID. Most of the object storage system supports
APIs to integrate it with software-defined data center and cloud environments.
Information Storage and Management (ISM) v4
Page 444
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Hierarchical File System Vs. Flat Address Space

Hierarchical file system organizes data in the form of files/directories
 Limits the number of files that can be stored

OSD uses flat address space that enables storing large number of objects
 Enables the OSD to meet the scale-out storage requirement of third platform
File Names/ Nodes
Object
Notes
Object ID
Metadata
Object
Object
Object
File-based storage systems (NAS) are based on file hierarchies that are complex in
structure. Most file systems have restrictions on the number of files,
directories and
Flat Address Space
Hierarchical File System
levels of hierarchy that can be supported, which limits the amount of data that can
be stored.
Data
Attributes
Object
Object
Object
OSD stores data using flat address space where the objects exist at the same level
and one object cannot be placed inside another object. Therefore, there is no
hierarchy of directories and files, and as a result, billions of objects are to be stored
in a single namespace. This enables the OSD to meet scale-out storage
requirement needs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 445
Object-Based and Unified Storage Lesson
Components of Object-Based Storage Device
VM
VM
Metadata
Service
Hypervisor
IP Network
Storage
Service
Internal
Network
OSD System
OSD system typically comprises three key components:

OSD nodes (controllers)

Internal network

Storage
Notes
The OSD system is composed of one or more nodes. A node is a server that runs
the OSD operating environment and provides services to store, retrieve, and
manage data in the system. Typically OSD systems are architected to work with
inexpensive x86-based nodes, each node provides both compute and storage
resources, and scales linearly in capacity and performance by simply adding
nodes.
The OSD node has two key services: metadata service and storage service. The
metadata service is responsible for generating the object ID from the contents (may
also include other attributes of data) of a file. It also maintains the mapping of the
object IDs and the file system namespace. In some implementations, the metadata
service runs inside an application server. The storage service manages a set of
disks on which the user data is stored.
The OSD nodes connect to the storage via an internal network. The internal
network provides node-to-node connectivity and node-to-storage connectivity. The
Information Storage and Management (ISM) v4
Page 446
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
application server accesses the node to store and retrieve data over an external
network. OSD typically uses low-cost and high-density disk drives to store the
objects. As more capacity is required, more disk drives can be added to the
system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 447
Object-Based and Unified Storage Lesson
Key Features of OSD
Typically, the object-based storage device has the following features:
Features
Description
Scale-out
architecture
Provides linear scalability where nodes are independently
added to the cluster to scale massively
Multitenancy
Enables multiple applications/clients to be served from the
same infrastructure
Metadata-driven
policy
Intelligently drive data placement, protection, and data
services based on the service requirements
Global namespace
Abstracts storage from the application and provides a
common view which is independent of location and making
scaling seamless
Flexible data
access method
Supports REST/SOAP APIs for web/mobile access, and file
sharing protocols (CIFS and NFS) for file service access
Automated system
management
Provides auto-configuring, auto-healing capabilities to reduce
administrative complexity and downtime
Data protection:
Geo distribution
Object is protected using either replication or erasure coding
technique and the copies are distributed across different
locations
Notes
Addition details for each OSD feature are:
Scale-out architecture: Scalability has always been the most important
characteristic of enterprise storage systems, since the rationale of consolidating
Information Storage and Management (ISM) v4
Page 448
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
storage assumes that the system can easily grow with aggregate demand. OSD is
based on distributed scale-out architecture where each node in the cluster
contributes with its resources to the total amount of space and performance. Nodes
are independently added to the cluster that provides massive scaling to support
petabytes and even exabytes of capacity with billions of objects that make it
suitable for cloud environment.
Multi-tenancy: Enables multiple applications to be securely served from the same
infrastructure. Each application is securely partitioned and data is neither comingled nor accessible by other tenants. This feature is ideal for businesses
providing cloud services for multiple customers or departments within an
enterprise.
Metadata-driven policy: Metadata and policy-based information management
capabilities combine to intelligently (automate) drive data placement, data
protection, and other data services (compression, deduplication, retention, and
deletion) based on the service requirements. For example, when an object is
created, it is created on one node and subsequently copied to one or more
additional nodes, depending on the policies in place. The nodes can be within the
same data center or geographically dispersed.
Global namespace: Another significant value of object storage is that it presents a
single global namespace to the clients. A global namespace abstracts storage from
the application and provides a common view, independent of location and making
scaling seamless. This unburdens client applications from the need to keep track of
where data is stored. The global namespace provides the ability to transparently
spread data across storage systems for greater performance, load balancing, and
non-disruptive operation. The global namespace is especially important when the
infrastructure spans multiple sites and geographies.
Flexible data access method: OSD supports REST/SOAP APIs for web/mobile
access, and file sharing protocols (CIFS and NFS) for file service access. Some
OSD storage systems support HDFS interface for big data analytics.
Automated system management: OSD provides self-configuring and autohealing capabilities to reduce administrative complexity and downtime. With
respect to services or processes running in the OSD, there is no single point of
failure. If one of the services goes down, and if the node becomes unavailable, or
site becomes unavailable, there are redundant components and services that will
facilitate normal operations.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 449
Object-Based and Unified Storage Lesson
Data protection: The objects stored in an OSD are protected using two methods:
replication and erasure coding. The replication provides data redundancy by
creating an exact copy of an object. The replica requires the same storage space
as the source object. Based on the policy configured for the object, one or more
replicas are created and distributed across different locations. Erasure coding
technique is discussed in the next slide.
Information Storage and Management (ISM) v4
Page 450
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Object Protection: Erasure Coding

Provides space-optimal data redundancy to protect data loss against multiple
drive failures
– A set of n disks is divided into m disks to hold data and k disks to hold
coding information
– Coding information is calculated from data
Data
Write
9 fragments
Encode
Encoded fragments
k=3
m=9
The figure illustrates an example of dividing a data into nine data segments (m = 9)
and three coding fragments (k = 3). The maximum number of drive failure
supported in this example is three.
Notes
Object storage systems support erasure coding technique that provides spaceoptimal data redundancy to protect data loss against multiple drive failures. In
storage systems, erasure coding can also ensure data integrity without using RAID.
This avoids the capacity overhead of keeping multiple copies and the processing
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 451
Object-Based and Unified Storage Lesson
overhead of running RAID calculations on very large data sets. The result is data
protection for very large storage systems without the risk of very long RAID rebuild
cycles.
In general, erasure coding technique breaks the data into fragments, encoded with
redundant data and stored across a set of different locations, such as disks,
storage nodes, or geographic locations. In a typical erasure coded storage system,
a set of n disks is divided into m disks to hold data and k disks to hold coding
information, where n, m, and k are integers. The coding information is calculated
from the data. If up to k of the n disks fail, their contents can be recomputed from
the surviving disks.
Erasure coding offers higher fault tolerance (tolerates k faults) than replication with
less storage cost. The additional storage requirement for storing coding segments
increases as the value of k/m increases.
Information Storage and Management (ISM) v4
Page 452
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Use Case: Cloud-Based Storage
The capabilities or features of OSD such as multi-tenancy, scalability, geographical
distribution of data, and data sharing across heterogeneous platforms or tenants
while ensuring integrity of data, make it a strong option for cloud-based storage.
Enterprise end-users and cloud subscribers are also interested in the cloud storage
offerings because it provides better agility, on-demand scalability, lower cost, and
operational efficiency compared to traditional storage solution.
Cloud storage provides unified and universal access, policy-based data placement,
and massive scalability. It also enables data access through or file access
protocols and provides automated data protection and efficiency to manage large
amount of data. With the growing adoption of cloud computing, cloud service
providers can leverage OSD to offer storage-as-a-service, backup-as-a-service,
and archive-as-a-service to their consumers.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 453
Object-Based and Unified Storage Lesson
VM
VM
VM
VM
Heterogeneous platforms or tenants
accessing data from cloud Storage
HTTP/S (REST, SOAP), NFS, CIFS
Global, Intelligent, Web-based, and Self-service
Site #1
Site #2
Site #3
Information Storage and Management (ISM) v4
Page 454
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Use Case: Cloud-based Object Storage Gateway
VM
VM
Cloud-based object storage
gateway
Hypervisor
iSCSi/FC/ FCoE
REST
Application Servers
Data Center
Object-based Cloud Storage
Gateways provide a translation layer between the standard interfaces (iSCSI, FC,
NFS, CIFS) and cloud provider’s REST API

Sits in a data center and presents file and block-based storage interfaces to
applications

Performs protocol conversion to send data directly to cloud storage

Encrypts the data before it transmits to the cloud storage

Supports deduplication and compression

Provides a local cache to reduce latency
Notes
The lack of standardized cloud storage APIs has made gateway appliance a crucial
component for cloud adoption. Typically service providers offer cloud-based object
storage with interfaces such as REST or SOAP, but most of the business
applications expect storage resources with block-based iSCSI or FC interfaces or
file-based interfaces, such as NFS or CIFS. The cloud-based object storage
gateways provide a translation layer between these standard interfaces and service
provider's REST API.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 455
Object-Based and Unified Storage Lesson
The gateway device is a physical or virtual appliance that sits in a data center and
presents file and block-based storage interfaces to the applications. It performs
protocol conversion so that data can be sent directly to cloud storage. To provide
security for the data sent to the cloud, most gateways automatically encrypt the
data before it is sent. To speed up data transmission times (as well as to minimize
cloud storage costs), most gateways support data deduplication and compression.
Cloud-based object storage gateway provides a local cache to reduce latency
associated with having the storage capacity far away from the data center. The
gateway appliances offer not only an interface to the cloud, but also provide a layer
of management that can even help to determine what data should be sent to the
cloud and what data should be held locally.
Information Storage and Management (ISM) v4
Page 456
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Video: Unified Storage
The video is located at
https://edutube.emc.com/Player.aspx?vno=IkvWeVAqqldarkMDHIfdig
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 457
Object-Based and Unified Storage Lesson
Unified Storage Overview
Definition: Unified Storage
A single integrated(converged) storage infrastructure that
consolidates block (iSCSI, FC, FCoE), file (CIFS/SMB, NFS), and
object (REST, SOAP) access.

Deploying unified storage provides following benefits
 Reduces capital and operational expenses
 Managed through single management interface
 Increases storage utilization

Integration with software-defined environment provides storage for mobile,
cloud, big data, and social applications
Notes
In an enterprise data center, typically different storage systems (block-based, filebased, and object-based storage) are deployed to meet the needs of different
applications. In many cases, this situation has been complicated by mergers and
acquisitions that bring together disparate storage infrastructures. The resulting silos
of storage have increased the overall cost because of complex management, low
storage utilization, and direct data center costs for power, space, and cooling.
An ideal solution would be to have an integrated storage solution that supports
block, file, and object access.
There are numerous benefits associated with deploying unified storage systems:
Creates a single pool of storage resources that can be managed with a single
management interface.
Information Storage and Management (ISM) v4
Page 458
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Sharing of pooled storage capacity for multiple business workloads should lead to a
lower overall system cost and administrative time, thus reducing the total cost of
ownership (TCO).
Provides the capability to plan the overall storage capacity consumption. Deploying
a unified storage system takes away the guesswork associated with planning for
file and block storage capacity separately.
Increased utilization, with no stranded capacity. Unified storage eliminates the
capacity utilization penalty associated with planning for block and file storage
support separately.
Provides the capability to integrate with software-defined storage environment to
provide next generation storage solutions for mobile, cloud, big data, and social
computing needs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 459
Object-Based and Unified Storage Lesson
Unified Storage Architecture
A unified storage architecture enables the creation of a common storage pool that
can be shared across a diverse set of applications with a common set of
management processes. The key component of a unified storage architecture is
unified controller. The unified controller provides the functionalities of block storage,
file storage, and object storage. It contains iSCSI, FC, FCoE, and IP front-end ports
for direct block access to application servers and file access to NAS clients.
SAN
NAS
(iSCSI/FC/FCOE)
(CIFS/NFS)
Block Request
Block Storage Functionality
Object
(REST/SOAP)
Object Request
File Request
NAS Functionality
OSD Functionality
Unified Controller
Unified Storage
Information Storage and Management (ISM) v4
Page 460
© Copyright 2019 Dell Inc.
Object-Based and Unified Storage Lesson
Notes
For block-level access, the controller configures LUNs and presents them to
application servers and the LUNs presented to the application server appear as
local physical disks. A file system is configured on these LUNs at the server and is
made available to applications for storing data.
For NAS clients, the controller configures LUNs and creates a file system on these
LUNs and creates a NFS, CIFS, or mixed share, and exports the share to the
clients. Some storage vendors offer REST API to enable object-level access for
storing data from the web/cloud applications.
In some implementation, there are dedicated or separate controllers for block
functionality, NAS functionality, and object functionality.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 461
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC Isilon

Dell EMC ECS

Dell EMC Unity
Information Storage and Management (ISM) v4
Page 462
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
Dell EMC Isilon
A scale-out NAS product powered by the OneFS operating environment. It enables
pooling multiple nodes together to construct a clustered NAS system. OneFS
creates a single file system that spans across all nodes in an Isilon cluster. Isilon
provides the capability to manage and store large (petabyte-scale), high-growth
data in a single system with the flexibility to meet a broad range of performance
requirements. Available in All-Flash, Hybrid and Archive platforms to support a
wide range of demanding file workloads.
Dell EMC ECS
Provides a hyper-scale storage infrastructure that is specifically designed to
support modern applications with unparalleled availability, protection, simplicity,
and scale. It provides universal accessibility with support for object, and HDFS.
ECS Appliance enables cloud service providers to deliver competitive cloud
storage services at scale. ECS provides a single platform for all web, mobile, Big
Data, and social media applications.
Dell EMC Unity
Delivers a full block and file unified environment in a single enclosure. The purpose
built Dell EMC Unity system can be configured as an All Flash system with only
solid state drives, or as a Hybrid system with a mix of solid state and spinning
media to deliver the best on both performance and economics. The Unisphere
management interface offers a consistent look and feel whether you are managing
block resources, file resources, or both. Dell EMC Unity offers multiple solutions to
address security and availability. Unified Snapshots provide point-in-time copies of
block and file data that can be used for backup and restoration purposes.
Asynchronous Replication offers an IP-based replication strategy within a system
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 463
Concepts in Practice Lesson
or between two systems. Synchronous Block Replication benefits FC environments
that are close together and require a zero data loss schema. Data at Rest
Encryption ensures user data on the system is protected from physical theft and
can stand in the place of drive disposal processes, such as shredding.
Information Storage and Management (ISM) v4
Page 464
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. Which file access method provides file sharing that is commonly used on UNIX
systems?
A. NTFS
B. NFS
C. CIFS
D. HDFS
2. Which type of storage device stores data on a flat address space based on its
content and attributes?
A. Block-based
B. Scale-up NAS
C. Scale-out NAS
D. Object-based
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 465
Summary
Summary
Information Storage and Management (ISM) v4
Page 466
© Copyright 2019 Dell Inc.
Software-Defined Storage and Networking
Introduction
This module presents on software-defined storage attributes and architecture. This
module also focuses on the functions of the control plane and of software-defined
storage. Further, this module focuses on the overview and architecture of softwaredefined networking.
Upon completing this module, you will be able to:




Explain software-defined storage attributes and architecture
Explain functions of the control plane
Explain extensibility of software-defined storage
Explain overview and architecture of SDN
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 467
Software-Defined Storage (SDS) Lesson
Software-Defined Storage (SDS) Lesson
Introduction
This lesson presents the drivers the drivers, the attributes, and the architecture of
software-defined storage. Further, this lesson covers asset discovery, resource
abstraction, pooling, and resource provisioning for services. Finally, this lesson
covers the application programming interface (API) and RESTful API.
This lesson covers the following topics:

List drivers for software-defined storage

Explain attributes of software-defined storage and architecture

Explain asset discovery, resource abstraction, pooling, and resource
provisioning

Explain application programming interface (API) and RESTful API
Information Storage and Management (ISM) v4
Page 468
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Software-Defined Storage (SDS)
Video: Introduction to Software-Defined Storage
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 469
Software-Defined Storage (SDS) Lesson
Drivers for Software-Defined Storage

In traditional environments, the creation of complex IT silos in data centers
leads to
 Management overhead, increased costs, and poor resource utilization

In data centers, critical functionality and management tied to storage system
limits
 Resource sharing, automation, and standardization

Traditional architecture makes it difficult to provide for:
 Data growth, scaling and self-service
Notes
In a traditional data center, there are several challenges in provisioning and
managing storage in an efficient and cost-effective manner. Some key challenges
are described here. In a traditional environment, each application type normally has
its own vertical stack of compute, networking, storage, and security. This leads to
the creation of a loose collection of IT silos, which increases the infrastructure’s
complexity. This challenges creates management overhead and increases
operating expenses. It also leads to poor resource utilization because capacity
cannot be shared across stacks. Data centers have multi-vendor, heterogeneous
storage systems, and each type of storage system (block-based, file-based, and
object-based) has its own unique value. However, critical functionality is often tied
to specific storage types, and each storage system commonly has its own
monitoring and management tools. There is limited resource sharing, no
centralized management, a little automation, and a lack of standards in this
environment. Application workload complexities and higher SLA demands pose a
further challenge to IT. IT finds it difficult to allocate storage to satisfy the capacity
requirements of applications in real time. There are also new requirements and
expectations for continuous access and delivery of resources as in a cloud
environment. Traditional environments are not architected for technologies such as
cloud computing, Big Data analytics, and mobile applications. Therefore, there are
several challenges in managing massive data growth, cost-effective scaling, and
providing self-service access to storage. These challenges have led to the advent
of the software-defined storage model.
Information Storage and Management (ISM) v4
Page 470
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
What Is Software-Defined Storage?
Definition: Software-Defined Storage (SDS)
Storage infrastructure managed and automated by software, which
pools heterogeneous storage resources, and dynamically allocates
them based on policy to match application needs.

Abstracts the physical details of storage and delivers storage as software

Supports multiple types of storage systems and access methods
 Enables storing data on both storage systems and commodity disks
 Provides a unified external view of storage infrastructure

Enables building cost-effective hyperscale storage infrastructure
Notes
SDS abstracts heterogeneous storage systems and their underlying capabilities,
and pools the storage resources. Storage capacity is dynamically and automatically
allocated from the storage pools based on policies to match the needs of
applications. In general, SDS software abstracts the physical details of storage
(media, formats, location, low-level hardware configuration), and delivers storage
as software. A storage system is a combination of hardware and software. The
software stack exposes the data access method such as block, file, or object. This
software stack also uses persistent media such as HDD or SSD to store the data.
SDS software separates the software layer of a storage system from the hardware.
It supports combinations of multiple storage types and access methods, such as
block, file, and object. It enables storing data on both storage systems and
commodity disks, while providing a unified external view of storage. This
functionality allows organizations to reuse existing storage assets, and mix and
match them with commodity resources. Thus SDS serve data through a single
namespace and storage system spread across these different assets. For example,
in a data center that contains several distinct file servers, SDS can provide a global
file system, spanning the file servers and allowing location-independent file access.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 471
Software-Defined Storage (SDS) Lesson
SDS enables organizations to build modern, hyperscale storage infrastructure in a
cost-effective manner using standardized, commercial off-the-shelf components.
The components individually provide lower performance. However, at sufficient
scale and with the use of SDS software, the pool of components provides greater
capacity and performance characteristics.
Information Storage and Management (ISM) v4
Page 472
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Key Attributes of Software-Defined Storage
SDS transforms existing heterogeneous physical storage into a simple, extensible,
and open virtual storage platform. The key attributes of software-defined storage
are as follows:
Attribute
Description
Storage abstraction and pooling
Single large storage pool spanning
across the underlying storage
infrastructure
Automated, policy-driven storage
provisioning
Dynamic composition of storage
services based on application policies
Unified management
Single control point for the entire
infrastructure
Self-service
Users self-provision storage services
from a service catalog
Open and extensible
Integration of external interfaces and
applications through the use of APIs
Notes
Additional details on the key attributes of software-defined storage are as follows:
Storage abstraction and pooling: SDS abstracts and pools storage resources
across heterogeneous storage infrastructure. SDS software creates a single large
storage pool with the underlying storage resources, from which several virtual
storage pools are created. SDS decouples the storage control path from the data
path. Applications connect to storage through the data path. Automated, policydriven storage provisioning: A “storage service” is some combination of capacity,
performance, protection, encryption, and replication. In the SDS model, storage
services are dynamically composed from available resources. SDS uses
application policies to create a “just-in-time” model for storage service delivery.
Storage assets and capabilities are configured and assigned to specific
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 473
Software-Defined Storage (SDS) Lesson
applications only when they are needed. If the policy changes, the storage
environment dynamically and automatically responds with the new requested
service level. Unified management: SDS provides a unified storage management
interface that provides an abstract view of the storage infrastructure. Unified
management provides a single control point for the entire infrastructure across all
physical and virtual resources. Self-service: Resource pooling enables multitenancy, and automated storage provisioning enables self-service access to
storage resources. Users select storage services from a self-service catalog and
self-provision them. Open and extensible: An SDS environment is open and easy
to extend enabling new capabilities to be added. An extensible architecture enables
integrating multi-vendor storage, and external management interfaces and
applications into the SDS environment through the use of application programming
interfaces (APIs).
Information Storage and Management (ISM) v4
Page 474
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Software-Defined Storage Architecture
External Management Interface
Written Applications
External Cloud / Object Storage
Service
Monitoring and Reporting Tools
Software-Defined Storage
REST API
Policy-Driven Control Plane
Data Services
Storage Management
Automation, Tenants, Self-Service, Provisioning
Virtual Storage Pools
Block Storage
Pool
Blocks, File, Object
Performance, Protection, Mobility
Object Storage
Pool
NAS Pool
Commodity
Multi-Vendor Heterogeneous Storage System (Data Plane)
The image depicts the generic architecture of a software-defined storage
environment. Although the physical storage devices themselves are central to SDS,
they are not a part of the SDS environment. Physical storage may be block-based,
file-based, or object-based storage systems or commodity hardware.
Notes
The fundamental component of the SDS environment is the policy-driven control
plane, which manages and provisions storage. The control plane is implemented
through software called “SDS controller”, which is also termed as a “storage
engine” in some SDS products. The SDS controller is software that manages,
abstracts, pools, and automates the physical storage systems into policy-based
virtual storage pools. By using automation and orchestration, the controller enables
self-service access to a catalog of storage resources. Users provision storage
using data services, which may be block, file, or object services. An SDS controller
may provide either all or a part of the features and services that are shown in the
architecture. For example, an SDS controller may only support file and block data
services. Some controllers may also support the Hadoop Distributed File System
(HDFS). Some SDS products provide the feature of creating a block-based storage
pool from the local direct-attached storage (DAS) of x86-based commodity servers
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 475
Software-Defined Storage (SDS) Lesson
in a compute cluster. The storage pool is then shared among the servers in the
cluster. The REST API is the core interface to the SDS controller. All underlying
resources managed by the controller are accessible through the API. The REST
API makes the SDS environment open and extensible, which enables integration of
multi-vendor storage, external management tools, and written applications. The API
also integrates with monitoring and reporting tools. Further, the API provides
access to external cloud/object storage.
Information Storage and Management (ISM) v4
Page 476
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Compute-Based Storage Area Network
ETH/ IB
Compute Systems with DAS
Compute-base SAN Storage Pool

A software-defined SAN created from direct-attached storage
 Creates a large block-based storage pool

A client program on compute systems exposes shared block volumes

Compute systems that contribute storage run a server program
 Server program performs I/O requested by client

Metadata manager configures and monitors the compute-based SAN
Notes
A compute-based storage area network is a software-defined virtual SAN created
from the direct-attached storage located locally on the compute systems in a
cluster. A compute-based SAN software creates a large pool of block-based
storage that can be shared among the compute systems (or nodes) in the cluster.
This software creates a large-scale SAN without storage systems, and enables
using the local storage of existing compute systems. The convergence of storage
and compute ensures that the local storage on compute systems, which often go
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 477
Software-Defined Storage (SDS) Lesson
unused, is not wasted. A compute system that requires access to the block storage
volumes, runs a client program. The client program is a block device driver that
exposes shared block volumes to an application on the compute system. The
blocks that the client exposes can be blocks from anywhere within the computebased SAN. This process enables the application to issue an I/O request, and the
client fulfills it regardless of where the particular blocks reside. The client
communicates with other compute systems either over Ethernet (ETH) or Infiniband
(IB) – a high-speed, low latency communication standard for compute networking.
The compute systems that contribute their local storage to the shared storage pool
within the virtual SAN, run an instance of a server program. The server program
owns the local storage and performs I/O operations as requested by a client from a
compute system within the cluster. A compute-based SAN’s control component,
which is known as the metadata manager, serves as the monitoring and
configuration agent. It holds cluster-wide mapping information and monitors
capacity, performance, and load balancing. It is also responsible for decisions
regarding migration, rebuilds, and all system-related functions. The metadata
manager is not on the virtual SAN data path, and reads and writes do not traverse
the metadata manager. The metadata manager may communicate with other
compute-based SAN components within the cluster to perform system
maintenance and management operations but not data operations. The metadata
manager may run on a compute system within the compute-based SAN, or on an
external compute system.
Information Storage and Management (ISM) v4
Page 478
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Benefits of Software-Defined Storage
The key benefits of software-defined storage are described below:
Benefit
Description
Simplified storage
environment

Breaks down storage silos and their associated complexity

Provides centralized management across all physical and
virtual storage environments

Simplifies management by enabling administrators to
centralize storage management and provisioning tasks

Automated policy-driven storage provisioning improves
quality of services, reduces errors, and lowers operational
cost

Provides faster streamlined storage provisioning, which
enables new requirements to be satisfied more rapidly
Agility

Ability to deliver self-service access to storage through a
service catalog provides agility and reduces time-tomarket
Reusing existing
infrastructure

Supports multi-vendor storage systems and commodity
hardware, which enables organizations to work with their
existing infrastructure and protects the current investments
of organizations
Operational
efficiency
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 479
Software-Defined Storage (SDS) Lesson
Cloud support

Enables an enterprise data center to connect to external
cloud storage services for consuming services such as
cloud-based backup, and disaster recovery

Facilitates extending object storage to existing file and
block-based storage, which enables organizations to
deploy mobile and cloud applications on their existing
infrastructure.
Information Storage and Management (ISM) v4
Page 480
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Control Plane Functions and User Interfaces
Key control plane functions are:

Asset discovery

Resource abstraction and pooling

Provisioning resources for services
SDS controller provides two native user interfaces:

Command-line interface (CLI)

Graphical user interface (GUI)
 Has an administrator view and a user view
Notes
The control plane in software-defined storage is implemented by SDS controller
software, which enables storage management and provisioning. An SDS controller
commonly provides two native user interfaces: a command-line interface (CLI) and
a graphical user interface (GUI). Both the interfaces may either be integrated into
the controller, or may be external to it. If the native user interfaces are external, and
then they apply the REST API to interact with the controller. The CLI provides
granular access to the controller’s functions and more control over controller
operations as compared to the GUI.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 481
Software-Defined Storage (SDS) Lesson
Asset Discovery

Controller automatically detects assets when they are added to the SDS
environment
 Controller obtains or confirms asset configuration information

Examples of asset categories that can be discovered are:
 Storage systems
 Storage networks
 Compute systems and clusters
 Data protection solutions
Notes
An SDS controller automatically detects an asset when it is added to the SDS
environment. The controller uses the asset’s credentials to connect to it over the
network, and either obtains or confirms its configuration information. This process
is called “discovery”. Discovery can also be initiated manually to verify the status of
an asset. Examples of assets are storage systems, storage networks, compute
systems and clusters, and data protection solutions. If the asset is a storage
system, the controller collects information about the storage ports and the pools
that it provides. If the asset is a compute system, the controller discovers its
initiator ports. Clusters can also be discovered, enabling volumes to be provisioned
to the compute systems in the cluster. The controller can also discover the storage
area networks within a data center.
Information Storage and Management (ISM) v4
Page 482
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Resource Abstraction and Pooling
Data centers commonly contain many physical storage systems of different types
and often from multiple manufacturers. Each physical storage system must also be
individually managed, which is time consuming and error prone.
An SDS controller exposes the storage infrastructure through a simplified model,
hiding and handling details such as storage system and disk selection, LUN
creation, LUN masking, and the differences between the storage systems.
The SDS controller leverages the intelligence of individual storage systems. It
abstracts storage across the physical storage systems and manages individual
components. This functionality enables administrators and users to treat storage as
a large resource. It enables focusing just on the amount of storage needed, and the
performance and protection characteristics required.
Physical Storage Abstraction
Flash
Pool
A
Pool
B
Flash
Pool
C
Pool
A
Pool
B
Pool
C
Pool
A
Pool
B
Pool
B
Pool
C
Pool
A
SATA
Pool
A
Pool
B
Pool
A
Pool
B
Pool
C
Pool
A
Pool
B
Pool
C
Pool
A
FC
FC
Pool
A
Flash
Pool
C
FC
SATA
Pool
B
Pool
C
Pool
C
SATA
Physical Storage
Pool
B
Pool
C
Abstracted Storage
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 483
Software-Defined Storage (SDS) Lesson
Resource Provisioning
Service Catalog and Self-Service

Administrator creates storage services and organizes them into categories in a
service catalog
 Services are block, file, and object data services
 Administrator can restrict services to specific users

Service catalog provides users with self-service access to predefined storage
services
 Users place service requests through the GUI or a client software

SDS controller automates the provisioning of resources

Administrators can view details of requests in real time
Block Data Service

Provides a block volume of required size, and performance and protection
levels

Examples of block services:
 Create a block volume
 Delete a block volume
 Bind a block volume to compute
 Unbind a block volume from compute
 Mount a block volume
 Unmount a block volume
 Expand a block volume
Information Storage and Management (ISM) v4
Page 484
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Notes
Service Catalog and Self-Service
After configuring the storage abstractions, an administrator customizes and
exposes storage services by creating service catalogs for tenants. The
administrator uses the GUI’s administrator view to create storage services and
organize them into categories in a service catalog. The service catalog provides the
tenant users with access to the set of predefined storage services. An administrator
can create different categories of services such as block service, file service, and
object service. The administrator can configure the different services within each
category, and also restrict them to specific users or user groups. The user view of
the GUI provides users within a tenant with access to their service catalog. The
user view presents all the services and categories that are available for
provisioning for a specific user. Users can request a service by simply clicking the
service and placing a request to run it. Some SDS platforms may not provide an
interface for users to request services, and require the use of external client
software. An SDS controller automates the provisioning of resources when a user
requests for a service. It employs a policy-based placement algorithm to find the
best fit in the infrastructure to fulfill user requests for data services. The SDS
controller uses orchestration for automating the provisioning process. Orchestration
uses workflows to automate the arrangement, coordination, and management of
various functions required to provision resources. As a result, provisioning does not
require administrator or user interaction.
Block Data Service
The block data service provides a block volume of required size, performance level,
and protection level to a user. Examples of the services that an administrator
defines in this service category are as follows: Create a block volume: A user can
create a block storage volume by selecting a virtual storage system and virtual
pool. On receiving the request, the SDS controller chooses the physical pool from
the selected virtual pool and storage system. It creates a block volume, which
corresponds to a LUN on the storage system. Delete a block volume: A user can
delete an existing volume. On receiving the request, the SDS controller destroys
the volume from the physical storage pool. Bind a block volume to compute: A user
can assign a block volume to a selected compute system/cluster. On receiving this
request, the SDS controller binds the block volume to the specified compute
system/cluster. However, the volume cannot be written to or read from unless it is
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 485
Software-Defined Storage (SDS) Lesson
mounted. Unbind block volume from compute: A user can unbind a volume from a
compute system/cluster. This block service simply makes the block volume invisible
to the compute. Mount a block volume: A user can mount a block volume on a
compute system/cluster. The SDS controller sends commands to the OS to mount
the volume. This operation is specific to the type of OS on the compute system
such as Windows, Linux, and ESXi. Unmount block volume: A user can unmount a
block volume from a compute system/cluster. On receiving the request, the SDS
controller sends commands to the compute to unmount the volume. Expand block
volume: A user can expand/extend a block volume by combining it either with a
newly created volume or with an existing volume. On receiving the request to
expand a volume, the SDS controller commands the storage system to expand the
LUN.
Information Storage and Management (ISM) v4
Page 486
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Software-Defined Storage Extensibility
Definition: Application Programming Interface (API)
A set of programmatic instructions and specifications that provides an
interface for software components to communicate with each other. It
specifies a set of routines that can be called from a software
component enabling interaction with the software providing the API.

A set of programmatic instructions and specifications that provides an interface
for software components to communicate with each other. It specifies a set of
routines that can be called from a software component enabling interaction with
the software providing the API.

Web-based APIs may be implemented as:
 Simple Object Access Protocol (SOAP) based web services
 Representational state transfer (REST) APIs
Notes
An API specifies a set of routines (operations), input parameters,
outputs/responses, datatype, and errors. The routines can be called from a
software component enabling it to interact with the software providing the API.
Thus, an API provides a programmable interface, which is a means for
communicating with an application without understanding its underlying
architecture. This functionality enables programmers to use the component-based
approach to build software systems. APIs may be pre-compiled code that is applied
in programming languages, and can also be web-based.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 487
Software-Defined Storage (SDS) Lesson
Need for APIs

APIs enable integrating third-party data services and capabilities into existing
architecture

In SDDC, APIs enable orchestration and provisioning resources from pools
 Ensures meeting the SLAs that organizations require

In SDS, the REST API provides the interface to all underlying resources
 Enables storage provisioning, management, and metering
 Enables extension of functionality, and integration with external platforms
and applications
Notes
As modern technologies become more prevalent, the ability to dynamically adapt to
variations in application workloads and storage requirements is becoming
increasingly important. The next-generation software-defined data centers and
cloud stacks are powered by APIs. With advancements in technology, APIs are
providing improving communication and connectivity between IT systems, and
increasing agility through automation. APIs provide a flexible, easy-to-use means
for integrating third-party applications and capabilities into existing infrastructure.
This integration also provides a layer of security between public (external) and
private (internal) business capabilities. Further enabling organizations to provide
services in the way they see fit while offering end users various services. For
example, a public cloud storage provider may provide an API that allows a
consumer-written application to access and use cloud storage as regular storage.
Similarly, online social networks may provide APIs that enable developers to
access to the feeds of their users. Further, with the advent of the Internet of Things,
devices enabled with web-based APIs are becoming common. APIs enable the
smart devices to communicate with each other and with applications. In a softwaredefined data center, APIs enable automated provisioning of resources from
compute, storage, and networking pools to ensure that SLAs are met. The use of
APIs is enabling software-defined storage to be easily managed and provisioned.
In SDS, the REST API provides the interface to all underlying resources.
Management interfaces use the API to provision, manage, monitor, and meter
logical storage resources. The API also provides a means to integrate with multi-
Information Storage and Management (ISM) v4
Page 488
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
vendor storage systems and external storage platforms. It also offers a
programmable environment enabling developers and users to extend SDS
functionality.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 489
Software-Defined Storage (SDS) Lesson
Representational State Transfer (REST)

REST is a client/server software architecture style
 Leverages HTTP methods for client/server interaction
 Used for developing “RESTful” APIs

Provides an easy means to consume services, and combine multiple web
resources into applications
Notes
Representational State Transfer (REST) is a client/server software architecture
approach that was originally introduced for building large-scale, distributed
hypermedia (for example, hypertext, audio, video, image, and text) systems. REST
is not a standard but rather an architectural style that has become a choice for
developing HTTP-based APIs called “RESTful” APIs. It leverages HTTP methods
such as GET, POST, PUT, DELETE for client/server interaction. It supports the
resource-oriented architecture for the development of scalable and lightweight web
applications while adhering to a set of constraints. REST-based communication
provides simple, human-readable data access methods. RESTful APIs do not
require XML-based web service protocols such as SOAP to support their lightweight interfaces. However, they still support XML-based and JSON data formats.
These services provide an easy means to consume services, and support the
combination of multiple web resources into new applications. Recent trends reveal
increasing adoption of REST for developing APIs to provide simple and costeffective request-based services, and support the demand for real-time data.
Information Storage and Management (ISM) v4
Page 490
© Copyright 2019 Dell Inc.
Software-Defined Storage (SDS) Lesson
Integrating External Management Tools and Applications
External Management
Interfaces and Applications
External Cloud/Object Storage
Services
Monitoring and Reporting
Tools
REST API
SDS Controller
Storage Systems
The REST API enables the extensibility of the SDS functionality through integration
with written applications, and external management tools and cloud stacks such as
VMware, Microsoft, and OpenStack. This provides an alternative to provisioning
storage from the native management interface. The open platform enables users
and developers to write new data services. This enables building an open
development community around the platform.
The API also integrates with tools for monitoring and reporting system utilization,
performance, and health. This also enables generating chargeback/showback
reports. The API may also support cloud/object storage platforms such as, Amazon
S3, and OpenStack Swift. Further, the API may also support integration with HDFS
for running Hadoop applications.
The REST API :

Describes the programmatic interfaces that allow users to create, read, update,
and delete resources through the HTTP methods PUT, GET, POST, and
DELETE

Accessible using any web browser or programming platform that can issue
HTTP requests
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 491
Software-Defined Storage (SDS) Lesson
The browser may require a special plugin such as httpAnalyzer for Internet
Explorer, Poster for Firefox, and PostMan for Chrome. The REST API may also be
accessed using scripting platforms such as Perl. Vendors may also provide class
libraries that enable developers to write applications that access the SDS data
services.
Information Storage and Management (ISM) v4
Page 492
© Copyright 2019 Dell Inc.
Software-Defined Networking (SDN) Lesson
Software-Defined Networking (SDN) Lesson
Introduction
This lesson presents an overview of Software-Defined Networking (SDN),
architecture of SDN along with a use case.
This lesson covers the following topics:

Overview of Software-Defined Networking (SDN)

Architecture of SDN

Use case of SDN
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 493
Software-Defined Networking (SDN) Lesson
Software-Defined Networking (SDN)
Software-Defined Networking Overview
Definition: Software-Defined Networking (SDN)
An approach to abstract and separate the control plane functions from
the data plane functions. Instead of the integrated control functions at
the network components level, the software external to the
components takes over the control functions. The software runs on a
compute system or a stand-alone device and is called network
controller.
VM
VM
VM
APP
APP
APP
OS
OS
OS
Control Plane
Network OS
Data Plane
Information Storage and Management (ISM) v4
Page 494
© Copyright 2019 Dell Inc.
Software-Defined Networking (SDN) Lesson

Controller gathers configuration information from network components

Controller provides instructions to data plane
Notes
Traditionally, a network component such as a switch or a router consists of a data
plane and a control plane. These planes are bundled together and implemented in
the firmware of the network components. The function of the data plane is to
transfer the network traffic from one physical port to another port by following rules
that are programmed into the component. The function of the control plane is to
provide the programming logic that the data plane follows for switching or routing of
the network traffic.
Software-defined networking is an approach to abstract and separate the control
plane functions from the data plane functions. Instead of the integrated control
functions at the network components level, the software external to the
components takes over the control functions. The software runs on a compute
system or a stand-alone device and is called network controller. The network
controller interacts with the network components to gather configuration information
and to provide instructions for data plane to handle the network traffic.
Software-defined networking versus network virtualization: Network virtualization is
a process of abstracting all the network components and their functions into
software. Whereas SDN does not virtualize all the network components, but moves
the decision making to a control plane. Based on the decision, the hardware
components execute the actions. Though they both allow for flexible network
operations, they perform different roles and functions.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 495
Software-Defined Networking (SDN) Lesson
Software-Defined Networking Architecture
Application Layer
Application
Application
Application Plane
Northbound APIs
Control Layer
Controller
Controller
Control Plane
Southbound APIs
Infrastructure Layer
Data Plane
Networking Device
Networking Device
The architecture of SDN consists of three layers along with APIs in between to
define the communication.

Infrastructure Layer: This layer consists of networking devices such as
switches and routers. It is responsible for handling data packets such as
forwarding or dropping of packets and handling the devices. This layer forms
the data plane and performs actions based on the instructions received.

Control Layer: This layer consists of controllers and acts as a the brain of the
SDN architecture. It is responsible for making decisions such as how the
packets should be forwarded based on the requirements, and relays the
decisions to the networking devices (data plane) for execution. It also extracts
the information about the network from the data plane and communicates it to
the application layer. This layer forms the control plane.

Application Layer: This layer consists of applications and services such as
business applications, and analytics that define the network behavior through
policies and also define the requirements. It communicates the requirements
through the APIs to the control layer. This layer forms the application plane of
the SDN architecture.

APIs: in SDN architecture, APIs are referred as northbound interfaces and
southbound interfaces. Northbound interfaces define the communications
Information Storage and Management (ISM) v4
Page 496
© Copyright 2019 Dell Inc.
Software-Defined Networking (SDN) Lesson
between the controller and application layer. Southbound interfaces define the
communications between the control and infrastructure layer.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 497
Software-Defined Networking (SDN) Lesson
Software-Defined Networking Benefits
Software-defined networking in a SAN provides several benefits. These benefits
are:
Benefit
Details
Centralized Control 
Policy-based
Automation
Simplified, Agile
Management
Provides a single point of control for the entire network
infrastructure that may span across data centers

Centralized control plane provides the programming logic
for transferring the network traffic, which can be uniformly
and quickly applied across the network infrastructure

Programming logic can be upgraded centrally to add new
features based on application requirements.

Many hardware-based network management operations
such as zoning can be automated

Management operations may be programmed in the
network controller based on business policies and best
practices

Reduces the need for manual operations that are
repetitive, error-prone, and time-consuming

Helps to standardize the management operations

Network controller usually provides a management
interface that includes a limited and standardized set of
management functions

Management functions are available in a simplified form,
abstracting the underlying operational complexity

Makes it easier to configure a network infrastructure and
to modify the network configuration to respond to changing
application requirements
Information Storage and Management (ISM) v4
Page 498
© Copyright 2019 Dell Inc.
Software-Defined Networking (SDN) Lesson
Notes

Centralized Control: The software-defined approach provides a single point of
control for the entire network infrastructure that may span across data centers.
The centralized control plane provides the programming logic for transferring
the network traffic, which can be uniformly and quickly applied across the
network infrastructure. The programming logic can be upgraded centrally to add
new features based on application requirements.

Policy-based Automation: With a software-defined approach, many hardwarebased network management operations such as zoning can be automated.
Management operations may be programmed in the network controller based
on business policies and best practices. This process reduces the need for
manual operations that are repetitive, error-prone, and time-consuming. Policybased automation also helps to standardize the management operations.

Simplified, Agile Management: The network controller usually provides a
management interface that includes a limited and standardized set of
management functions. With policy-based automation in place, these
management functions are available in a simplified form, abstracting the
underlying operational complexity. This process makes it easy to configure a
network infrastructure and to modify the network configuration to respond to
changing application requirements.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 499
Software-Defined Networking (SDN) Lesson
Software-Defined Networking Use Case
Listed some common use cases where SDN is used to strengthen the security,
automate the processes for faster provisioning of network resources and enable
business continuity.
Use Case
Details
Data Center
Security

Security against lateral movements

Visibility of trends using analytics such as switch data

Security policies and control for each workload

Automated network provisioning

Programmatically control the entire network environment

Hybrid cloud initiatives

Disaster recovery
Automation
Business
Continuity
Note: Micro-segmentation is a method of isolating and securing the workloads by
defining various security policies and controls for each workload.
Notes

Data Center Security: Protecting information is a strategic necessity for
organizations. With SDN, organizations protect data through embedded
security, to prevent credential stealing and computer infiltration for both the
physical and virtual layers. It enables visibility of trends using analytics available
that offer insight into switch traffic. Micro-segmentation feature of SDN lets
organizations define security policies and controls for each workload based on
dynamic security groups. This process helps to ensure immediate responses to
threats inside the data center.

Automation: Many organizations cannot change their networks fast enough to
keep up with new applications and workloads. With SDN, Organizations can
Information Storage and Management (ISM) v4
Page 500
© Copyright 2019 Dell Inc.
Software-Defined Networking (SDN) Lesson
bring up workloads in seconds or minutes using automated network
provisioning. There is no need to make major revisions to the physical network
every time the organization introduces an application or service. Changes can
be quickly made through software and require few, if any, cabling updates. IT
can programmatically create, snapshot, store, move, delete, and restore entire
networking environments with simplicity and speed. This automation of
networking tasks benefits both new application deployments as well as changes
to existing applications in the IT infrastructure.

Business Continuity: SDN also simplifies and accelerates private and hybrid
cloud initiatives. Organizations can rapidly develop, automatically deliver, and
manage all their enterprise applications, whether they reside on-premises or offpremises, from a single unified platform. IT can easily replicate entire
application environments to remote data centers for disaster recovery. It can
also move them from one corporate data center to another or deploy them into
a hybrid cloud environment, without disrupting the applications or touching the
physical network.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 501
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC ViPR Controller

Dell EMC VxFlex OS

VMware NSX
Information Storage and Management (ISM) v4
Page 502
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
Dell EMC ViPR Controller
A software-defined storage platform that abstracts, pools, and automates a data
center’s physical storage infrastructure. It delivers block and file storage services
on demand through a self-service catalog. It supports data protection across
geographically dispersed data centers. It provides a single control plane to manage
heterogeneous storage environments, including Dell EMC and non-Dell EMC block
and file storage.
ViPR Controller also provides a REST-based API making the storage architecture
extensible. It supports multiple vendors enabling organizations to choose storage
platforms from either Dell EMC or third-party. It also supports different cloud stacks
such as VMware, Microsoft, and OpenStack. ViPR Controller development is driven
by the open-source community, which enables expanding its features and
functionalities.
Dell EMC VxFlex OS
Software that creates a server and IP-based SAN from direct-attached server
storage to deliver flexible and scalable performance and capacity on demand. As
an alternative to a traditional SAN infrastructure, VxFlex OS combines HDDs,
SSDs, and PCIe flash cards to create a virtual pool of block storage with varying
performance tiers. It decouples compute and storage, and scales each resource
together or independently to drive maximum efficiency and to eliminate wasted
CAPEX at scale. Distributed I/O Parallelism vs. Data Locality: uses all resources to
deliver against all I/O requests to drive massive performance. Eliminates
bottlenecks and scales performance linearly.
VxFlex OS is built for workload variability and consolidates many workloads onto a
single system with consistent performance for all. For storage utilization , VxFlex
OS is completely agnostic because the OS and Hypervisor enable the sharing of
storage resources across multiple operating systems/clusters. Regarding
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 503
Concepts in Practice Lesson
compute/RAM utilization, VxFlex OS is extremely lightweight. It provides massive
CAPEX savings at scale for core data center workloads.
VMware NSX
A network virtualization platform for SDDC architecture. It is a reproduction of the
network and its services, in a virtualized environment. NSX provides software that
represents logical network components such as switches, routers, distributed
services for firewalls, load balancers, and VPN. It reproduces Layer 2 to Layer 7
networking services that include switching, routing, firewalling, and load balancing
in software.
VMware NSX lets you create, delete, save, and restore networks without changing
the physical network. This process reduces the time to provision by simplifying
overall network operations. NSX Manager is integrated with vCenter for single pane
management and all these network resources can be deployed whether in a cloud
or a self-service portal environment.
Information Storage and Management (ISM) v4
Page 504
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. Which product creates IP-based SAN from direct attached server storage ?
A. Dell EMC VxFlex OS
B. VMware NSX
C. VMware vSphere
D. Dell EMC NetWorker
2. Which layer represents the ‘brain’ of SDN architecture?
A. Control
B. Infrastructure
C. Application
D. API
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 505
Summary
Summary
Information Storage and Management (ISM) v4
Page 506
© Copyright 2019 Dell Inc.
Introduction to Business Continuity
Introduction
Upon completing this module, you will be able to:
 Explain business continuity (BC) and information availability
 Describe the causes and impact of information unavailability
 List various BC technology solutions
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 507
Business Continuity Overview Lesson
Business Continuity Overview Lesson
Introduction
This lesson presents importance of business continuity, causes and impact of
information unavailability, and measurement of information availability. This lesson
also focuses on RPO and RTO, disaster recovery, and various BC technology
solutions.
This lesson covers the following topics:

Importance of business continuity

Causes and impact of information unavailability

Measurement of information availability

Recovery Point Objective (RPO) and Recovery Time Objective (RTO)

Disaster recovery

Business continuity technology solutions
Information Storage and Management (ISM) v4
Page 508
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Business Continuity Overview
Video: Business Continuity Overview
The video is located at
https://edutube.emc.com/Player.aspx?vno=0bTlYemOy9CMIfw5AoCgQw
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 509
Business Continuity Overview Lesson
Business Continuity
Definition: Business Continuity (BC)
Process that prepares for, responds to, and recovers from a system
outage that can adversely affect business operations.

BC process enables continuous availability of information and services in the
event of failure to meet the required SLA

BC involves various proactive and reactive countermeasures

It is important to automate BC process to reduce the manual intervention

Goal of BC solution is to ensure information availability
Notes
Business continuity (BC) is a set of processes that includes all activities that a
business must perform to mitigate the impact of planned and unplanned downtime.
BC entails preparing for, responding to, and recovering from a system outage that
adversely affects business operations. It describes the processes and procedures
an organization establishes to ensure that essential functions can continue during
and after a disaster.
Business continuity prevents interruption of mission-critical services, and
reestablishes the impacted services as swiftly and smoothly as possible by using
an automated process. BC involves proactive measures such as business impact
analysis, risk assessment, building resilient IT infrastructure, deploying data
protection solutions (backup and replication). It also involves reactive
countermeasures such as disaster recovery.
In a modern data center, policy-based services can be created that include data
protection through the self-service portal. Consumers can select the class of
service that best meets their performance, cost, and protection requirements on
demand. Once the service is activated, the underlying data protection solutions that
are required to support the service is automatically invoked to meet the required
data protection.
Information Storage and Management (ISM) v4
Page 510
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
For example: If a service requires VM backup for every six hours and then backing
up VM is scheduled automatically every six hours.The goal of a BC solution is to
ensure “information availability” required to conduct vital business operations.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 511
Business Continuity Overview Lesson
Importance of Business Continuity
Today, businesses rely on information more than ever. Continuous access to
information is a must for the smooth functioning of business operations for any
organization.
Listed are some important factors:
Application
Dependency
Business applications rely on data protection techniques for
uninterrupted and reliable access to data
High-risk Data
Organizations seek to protect their sensitive data to reduce the
risk of financial, legal, and business loss
Data
Protection
Laws
Legal requirements mandate protection against unauthorized
modification, loss, and unlawful processing of personal data
Notes
For business applications, it is essential to have uninterrupted, fast, reliable, and
secure access to data for enabling these applications to provide services. This
access, in turn, relies on how well the infrastructure and data is protected and
managed.
Data is the most valuable asset for an organization. An organization can use its
data to efficiently bill customers, advertise relevant products to the existing and
potential customers. It also enables organizations to launch new products and
services, and perform trend analysis to devise targeted marketing plans. These
sensitive data, if lost, may lead to significant financial, legal, and business loss
apart from serious damage to the reputation of an organization. An organization
seeks to reduce the risk of sensitive data loss to operate its business successfully.
It should focus its protection efforts where the need exists—its high-risk data.
Information Storage and Management (ISM) v4
Page 512
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Many government laws mandate that an organization must be responsible for
protecting its employee’s and customer’s personal data. The data should be safe
from unauthorized modification, loss, and unlawful processing. Examples of such
laws are U.S. Health Insurance Portability and Accountability Act (HIPAA), U.S.
Gramm-Leach-Bliley Act (GLBA), and U.K. Data Protection Act. An organization
must be proficient at protecting and managing personal data in compliance with
legal requirements.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 513
Business Continuity Overview Lesson
Information Availability
Definition: Information Availability (IA)
The ability of an IT infrastructure to function according to business
requirements and customer expectations, during its specified time of
operation.
Information Availability can be defined in terms of:
Accessibility Information should be accessible to the right user when required.
Reliability
Information should be reliable and correct in all aspects. It is “the
same” as what was stored and there is no alternation or corruption
to the information.
Timeliness
Defines the time window (a particular time of the day, week, month,
and year as specified) during which information must be
accessible.
For example: if online access to an application is required between
8:00 am and 10:00 pm each day, any disruption to data availability
outside of this time slot is not considered to affect timeliness.
Information Storage and Management (ISM) v4
Page 514
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Causes of Information Unavailability

Application failure (for example: due to catastrophic exceptions caused by bad
logic)

Data loss

Infrastructure component failure (for example: due to power failure or disaster)

Data center or site down
 For example: due to power failure or disaster

Refreshing IT infrastructure
Notes
Data center failure due to disaster (natural or man-made disasters such as flood,
fire, earthquake, and so on) is not the only cause of information unavailability. Poor
application design or resource configuration errors can lead to information
unavailability. For example, if the database server is down for some reason, then
the data is inaccessible to the consumers, which leads to IT service outage.
Even the unavailability of data due to several factors (data corruption and human
error) leads to outage. The IT department is routinely required to take on activities
such as refreshing the data center infrastructure, migration, running routine
maintenance, or even relocating to a new data center. Any of these activities can
have its own significant and negative impact on information availability.
Note: In general, the outages can be broadly categorized into planned and
unplanned outages.

Planned outages may include installation and maintenance of new hardware,
software upgrades or patches, performing application and data restores, facility
operations (renovation and construction), and migration.

Unplanned outages include failure caused by human errors, database
corruption, failure of physical and virtual components, and natural or humanmade disasters.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 515
Business Continuity Overview Lesson
Impact of Information Unavailability
An IT service outage, due to information unavailability, results in loss of
productivity, loss of revenue, poor financial performance, and damages to
reputation. The loss of revenue includes direct loss, compensatory payments,
future revenue loss, billing loss, and investment loss. The damages to reputations
may result in a loss of confidence or credibility with customers, suppliers, financial
markets, banks, and business partners. The other possible consequences of
outage include the cost of extra rented equipment, overtime, and extra shipping.
Lost Productivity
- Number of employees impacted
hours out x hourly rate
Lost Revenue
x
Know the downtime costs (per hour, day, two
days, and so on.)
- Direct loss
- Compensatory payments
- Lost future revenue
- Billing losses
- Investment losses
Financial Performance
Damaged Reputation
- Customers
- Revenue recognition
- Suppliers
- Cash flow
- Financial markets
- Lost discounts (A/P)
- Banks
- Payment guarantees
- Business partners
- Credit rating
- Stock price
Other Expenses
- Temporary employees, equipment rentals, overtime costs, extra shipping
costs, travel expenses, and so on.
Information Storage and Management (ISM) v4
Page 516
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Measurement of Information Availability
Information availability relies on the availability of both physical and virtual
components of a data center. The failure of these components might disrupt
information availability. A failure is the termination of a component’s ability to
perform a required function.
The component’s ability can be restored by performing various external corrective
actions, such as a manual reboot, a repair, or replacement of the failed
component(s). Proactive risk analysis, performed as part of the BC planning
process, considers the component failure rate and average repair time, which are
measured by MTBF and MTTR.
Time to repair or 'downtime'
Response Time
Detection
Incident
Recovery Time
Repair
Diagnosis
Detection
elapsed time
Restoration
Incident
Recovery
Repair time
Time
Time between failures or 'uptime'
MTBF: Average time available for a system or component to perform its normal
operations between failures

MTBF = Total uptime / Number of failures
MTTR: Average time required to repair a failed component

MTTR = Total downtime / Number of failures
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 517
Business Continuity Overview Lesson
IA = MTBF / (MTBF + MTTR) or IA = Uptime / (Uptime + Downtime)
Information Storage and Management (ISM) v4
Page 518
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Key BC Concepts: RPO and RTO
Recovery Point Objectives (RPO)
Recovery Time Objectives (RTO)
Point-in-time to which data must be
recovered.
Time within which systems and
applications must be recovered.
Disaster
Time
RPO = Amount of data loss that a
business can endure
RTO = Amount of downtime that a
business can endure
Notes
When designing an information availability strategy for an application or a service,
organizations must consider two important parameters that are closely associated
with recovery.

Recovery Point Objective: RPO is the point-in-time to which data must be
recovered after an outage. It defines the amount of data loss that a business
can endure. Based on the RPO, organizations plan for the frequency with which
a backup or replica must be made. For example, if the RPO of a particular
business application is 24 hours, then backups are created every midnight. The
corresponding recovery strategy is to restore data from the set of last backups.
An organization can plan for an appropriate BC solution on the basis of the
RPO it sets.

Recovery Time Objective: RTO is the time within which systems and
applications must be recovered after an outage. It defines the amount of
downtime that a business can endure and survive. Based on the RTO, an
organization can decide which BC technology is best suited. The more critical
the application, the lower the RTO should be.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 519
Business Continuity Overview Lesson
Both RPO and RTO are counted in minutes, hours, or days and are directly related
to the criticality of the IT service and data. Usually, the lower the RTO and RPO,
the higher is the cost of a BC solution or technology.
Information Storage and Management (ISM) v4
Page 520
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
BC Planning Lifecycle
BC planning must follow a disciplined approach like any other planning process.
Organizations today dedicate specialized resources to develop and maintain BC
plans. From the conceptualization to the realization of the BC plan, a lifecycle of
activities can be defined for the BC process. The BC planning lifecycle includes five
stages:
Establish Objectives

Determine BC requirements

Estimate the scope and budget to achieve requirements

Select a BC team that includes subject matter experts from all areas of
business, whether internal or external

Create BC policies
Analyze

Collect information on data profiles, business processes, infrastructure support,
dependencies, and frequency of using business infrastructure

Conduct a business impact analysis

Identify critical business processes and assign recovery priorities

Perform risk analysis for critical functions and create mitigation strategies

Perform cost benefit analysis for available solutions based on the mitigation
strategy

Evaluate options
Design and Develop
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 521
Business Continuity Overview Lesson

Define the team structure and assign individual roles and responsibilities; for
example, different teams are formed for activities such as emergency response
and infrastructure and application recovery

Design data protection strategies and develop infrastructure

Develop contingency solution and emergency response procedures

Detail recovery and restart procedures
Implement

Implement risk management and mitigation procedures that include backup,
replication, and management of resources

Prepare the DR sites that can be utilized if a disaster affects the primary data
center. The DR site could be one of the organization’s own data center or could
be a cloud

Implement redundancy for every resource in a data center to avoid single points
of failure
Train, Test, Assess, and Maintain

Train the employees who are responsible for backup and replication of
business-critical data on a regular basis or whenever there is a modification in
the BC plan

Train employees on emergency response procedures when disasters are
declared

Train the recovery team on recovery procedures based on contingency
scenarios

Perform damage-assessment processes and review recovery plans

Test the BC plan regularly to evaluate its performance and identify its limitations

Assess the performance reports and identify limitations

Update the BC plans and recovery/restart procedures to reflect regular changes
within the data center
Information Storage and Management (ISM) v4
Page 522
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 523
Business Continuity Overview Lesson
Key BC Concepts: Disaster Recovery
Definition: Disaster Recovery (DR)
A part of BC process, which involves a set of policies and procedures
for restoring IT infrastructure, including data that is required to support
ongoing IT services, after a natural or human-induced disaster occurs.
A disaster may impact the ability of a data center to remain up and provide services
to users. This disaster may cause information unavailability. Disaster recovery (DR)
mitigates the risk of information unavailability due to a disaster. It involves a set of
policies and procedures for restoring IT infrastructure including data. This
infrastructure and data are required to support the ongoing IT services after a
disaster occurs.
Before Disaster
After Disaster
Data Access
Data Access
Replication
Primary Site
DR Site
Primary Site
DR Site
Notes
The fundamental principle of DR is to maintain a secondary data center or site,
called a DR site. The primary data center and the DR data center should be located
in different geographical regions to avoid the impact of a regional disaster. The DR
site must house a complete copy of the production data. Commonly, all production
data is replicated from the primary site to the DR site either continuously or
periodically. A backup copy can also be maintained at the DR site. Usually, the IT
infrastructure at the primary site is unlikely to be restored within a short time after a
catastrophic event.
Organizations often keep their DR site ready to restart business operations if there
is an outage at the primary data center. This may require the maintenance of a
Information Storage and Management (ISM) v4
Page 524
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
complete set of IT resources at the DR site that matches the IT resources at the
primary site. Organization can either build their own DR site, or they can use cloud
to build DR site.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 525
Business Continuity Overview Lesson
Business Continuity Technology Solutions
Implementing fault tolerance mechanism
Deploying data protection solutions
High Availability and Data
Protection Solutions
Automatic failover mechanisms
Architecting resilient modern applications
Notes
With the aim of meeting the required information and service availability, the
organizations should build a resilient IT infrastructure. Building a resilient IT
infrastructure requires the following high availability and data protection solutions:

Deploying redundancy at both the IT infrastructure component level and the site
level to avoid single point of failure

Deploying data protection solutions such as backup, replication, migration, and
archiving

Automatic failover mechanism is one of the important methods as well. It is one
the efficient and cost effective way to ensure HA. For example, scripts can be
defined to bring up a new VM automatically when the current VM stops
responding or goes down.

Architecting resilient modern applications
For example: when a disaster occurred at one of the data centers of an
organization, the BC triggers the DR process. This process typically involves both
manual and automated procedure to reactivate the service (application) at a
functioning data center. This reactivation of service requires the transfer of
Information Storage and Management (ISM) v4
Page 526
© Copyright 2019 Dell Inc.
Business Continuity Overview Lesson
application users, VMs, data, and services to the new data center. This process
involves the use of redundant infrastructure across different geographic locations,
live migration, backup, and replication solutions.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 527
Business Continuity Overview Lesson
Video: Business Continuity Solutions
The video is located at
https://edutube.emc.com/Player.aspx?vno=ENZH/0JvsHUSzSGDh4zpcg
Information Storage and Management (ISM) v4
Page 528
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Business Continuity Fault Tolerance Lesson
Introduction
This lesson presents key requirements for fault tolerance. This lesson also focuses
on component-level and site-level fault tolerance techniques.
This lesson covers the following topics:

Key requirements for fault tolerance

Component-level fault tolerance techniques

Site-level fault tolerance techniques
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 529
Business Continuity Fault Tolerance Lesson
Fault Tolerance IT Infrastructure
Fault Tolerance IT Infrastructure Overview
Definition: Fault Tolerance
Ability of an IT system to continue functioning in the event of a failure.
Fault tolerance ensures that a single fault or failure does not make an entire system
or a service unavailable. It protects an IT system or a service against various types
of unavailability.
Transient Unavailability
Fault
Tolerance
Deals
with
Fault
Failure
Due
to
Hardware Outage
Software Issues User
Errors
That
Cause
Intermittent Unavailability
Permanent Unavailability
Notes
A fault may cause a complete outage of a component or cause a faulty component
to run but only to produce incorrect or degraded output. The common reasons for a
fault or a failure are: hardware failure, software issue, and administrator/user
errors. Fault tolerance ensures that a single fault or failure does not make an entire
system or a service unavailable.
Fault tolerance protects an IT system or a service against the following types of
unavailability:

Transient unavailability: It occurs once for short time and then disappears. For
example, an online transaction times out but works fine when a user retries the
operation.
Information Storage and Management (ISM) v4
Page 530
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson

Intermittent unavailability: It is a recurring unavailability that is characterized by
an outage and then availability again and then another outage, and so on.

Permanent unavailability: It exists until the faulty component is repaired or
replaced. Examples of permanent unavailability are network link outage,
application issues, and manufacturing defects.
Fault tolerance may be provided by software, hardware, or a combination of both.
The closer an organization reaches 100 percent fault tolerance, the more costly is
the infrastructure
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 531
Business Continuity Fault Tolerance Lesson
Key Requirements for Fault Tolerance
A fault tolerant IT infrastructure should meet two key requirements such as fault
isolation and eliminating single points of failure (SPOF).
Fault Isolation
Key Requirements for Fault
Tolerance
Eliminating Single Points of Failure
Information Storage and Management (ISM) v4
Page 532
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Fault Isolation
Fault isolation limits the scope of a fault into local area so that the other areas of a
system are not impacted by the fault. It does not prevent failure of a component but
ensures that the failure does not impact the overall system.
Fault isolation requires a fault detection mechanism that identifies the location of a
fault and a contained system design (like sandbox) that prevents a faulty system
component from impacting other components.
Isolated Dead Path
VM
VM
HBA
SAN
Storage
Port
HBA
SAN
Storage
Port
= Points of Fault
Hypervisor
Compute System
Pending I/Os are
Redirected to Live Path
Live Path
Storage
System
The example represents two I/O paths between a compute system and a storage
system. The compute system uses both the paths to send I/O requests to the
storage system. If an error or fault occurs on a path causing a path failure, the fault
isolation mechanism present in the environment automatically detects the failed
path. It isolates the failed path from the set of available paths and marks it as a
dead path to avoid sending the pending I/Os through it. All pending I/Os are
redirected to the live path. This helps avoiding the time-out and the retry delays.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 533
Business Continuity Fault Tolerance Lesson
Single Point of Failure
Definition: Single Point of Failure
Refers to any individual component or aspect of an infrastructure
whose failure can make the entire system or service unavailable.
Single point of failure may occur at infrastructure component-level and site-level
(data center).
SPOF at Storage-level
SPOF at Networklevel
VM
VM
SPOF at Site-level
SPOF at Computelevel
Hypervisor
FC Switch
Compute System
Storage System
Data Center
The illustration provides an example where various IT infrastructure components,
including the compute system, VM instance, network devices, storage, and site
itself, become a single point of failure. Assume that a web application runs on a VM
instance and it uses a database server which runs on another VM to store and
retrieve application data. If the database server is down and then the application
would not be able to access the data and in turn would impact the availability of the
service.
Consider another example where a group of compute systems is networked
through a single FC switch. The switch would present a single point of failure. If the
switch failed, all of the compute systems connected to that switch would become
inaccessible and result in service unavailability. It is important for organizations to
build a fault tolerance IT infrastructure that eliminates single points of failure in the
environment.
Information Storage and Management (ISM) v4
Page 534
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Eliminating Single Points of Failure

Single points of failure can be avoided by implementing fault tolerance
mechanisms such as redundancy

Implement redundancy at component level
 Compute
 Network
 Storage

Implement multiple availability zones
 Avoid single points of failure at data center (site) level

It is important to have high availability mechanisms that enable automated
application/service failover
It is important to have high availability mechanisms that enable automated
application/service failover
Notes
Highly available infrastructures are typically configured without single points of
failure to ensure that individual component failures do not result in service outages.
The general method to avoid single points of failure is to provide redundant
components for each necessary resource, so that a service can continue with the
available resource even if a component fails.
Organizations may also create multiple availability zones to avoid single points of
failure at data center level. Usually, each zone is isolated from others, so that the
failure of one zone would not impact the other zones. It is important to have high
availability mechanisms that enable automated application/service failover within
and across the zones if there is a component failure or disaster.
Note:
N+1 redundancy is a common form of fault tolerance mechanism that ensures
service availability if there is a component failure. A set of N components has at
least one standby component. This approach is typically implemented as an
active/passive arrangement, as the additional component does not actively
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 535
Business Continuity Fault Tolerance Lesson
participate in the service operations. The standby component is active only if any
one of the active components fails.
N+1 redundancy with active/active component configuration is also available. In
such cases all the component remains active. For example, if an active/active
configuration is implemented at the site level and then a service is fully deployed in
both the sites. The load for this service is balanced between the sites. If one of the
sites is down, the available site would manage the service operations and manage
the workload.
Information Storage and Management (ISM) v4
Page 536
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Implementing Redundancy at Component-Level
Organizations should follow stringent guidelines to implement fault tolerance in
their data centers for uninterrupted services. The underlying IT infrastructure
components (compute, storage, and network) should be highly available and the
single points of failure at the component level should be avoided.
Clustered
Compute System
VM
VM
Redundant
Links
Techniques to protect Compute/Network/Storage: Clustering, VM live
migration, Link and switch aggregation, NIC teaming, Multipathing,
Configuring redundant hot swappable components, RAID and Erasure
Coding, Dynamic disk sparing, Configuring redundant storage system
components
Hypervisor
Clients
NIC Teaming
Remote Site
Redundant
HBAs
Redundant FC
Switches
LAN/WAN
Redundant
Network
VM
VM
APP
APP
OS
OS
VMM
VMM
Hypervisor Kernel
NIC Teaming
Redundant
Ports
Redundant
Storage
System
Notes
The example represents an infrastructure that is designed to mitigate the single
points of failure at component level. The single points of failure at the compute level
can be avoided by implementing redundant compute systems in a clustered
configuration. Single points of failure at the network level can be avoided through
path and node redundancy and various fault tolerance protocols.
Multiple independent paths can be configured between nodes so that if a
component along the main path fails, traffic is rerouted along another path. The key
techniques for protecting storage from single points of failure are RAID, erasure
coding techniques, dynamic disk sparing, and configuring redundant storage
system components. Many storage systems also support redundant array
independent nodes (RAIN) architecture to improve the fault tolerance.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 537
Business Continuity Fault Tolerance Lesson
Compute Clustering
Service Failover
Compute Cluster
Heartbeat Signal

Two or more compute systems/hypervisors are clustered to provide high
availability and load balancing

Service running on a failed compute system moves to another compute system

Two common clustering implementations are:
 Active/active
 Active/passive
Notes
Compute clustering is one of the key fault tolerance mechanisms. It provide
continuous availability of service even when a VM instance, physical compute
systems, operating system, or hypervisor fails.
Clustering is a technique where at least two compute systems (or nodes) work
together and are viewed as a single compute system to provide high availability
and load balancing. If one of the compute systems fails, the service running in the
compute system can failover to another compute system in the cluster. This
method minimizes or avoids any outage.
The two common cluster implementations are active/active and active/passive.
Information Storage and Management (ISM) v4
Page 538
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson

In active/active clustering, the nodes in a cluster are all active participants and
run the same service of their clients. The active/active cluster balances requests
for service among the nodes. If one of the nodes fails, the surviving nodes take
the load of the failed one. This method enhances both the performance and the
availability of a service. The nodes in the cluster have access to shared storage
volumes. In active/active clustering only one node can write or update the data
in a shared file system or database at a given time.

In active/passive clustering, the service runs on one or more nodes and the
passive node waits for a failover. If the active node fails, the service that had
been running on the active node is failed over to the passive node.
Active/passive clustering does not provide performance improvement like
active/active clustering.
Clustering uses a heartbeat mechanism to determine the health of each node in the
cluster. The exchange of heartbeat signals, usually happens over a private network
enables participating cluster members to monitor one another’s status.
Clustering can be implemented between multiple physical compute systems, or
between multiple VMs, or between VM and physical compute system, or between
multiple hypervisors.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 539
Business Continuity Fault Tolerance Lesson
Compute Cluster Example

Multiple hypervisors running on different systems are clustered

Provides continuous availability of services running on VMs
VM
Primary VM
Hypervisor
Record
Events
Logging Traffic
Reply
Events
Hypervisor Clustering
SecondaryV
M
VM
Hypervisor
Acknowledgement
Network
Storage System
Notes
The illustration shows an example of clustering where multiple hypervisors running
on different compute systems are clustered. They are accessing hypervisor’s native
file system which is a clustered file system that enables multiple hypervisors to
access the same shared storage resources concurrently. This method provides
high availability for services running on VMs by pooling the VMs and compute
systems that reside on into a cluster.
If a physical compute system running a VM fails, the VM is restarted on another
compute system in the cluster. This method provides rapid recovery of services
running on VMs if there is a compute system failure. In some hypervisor cluster
implementations, the hypervisor uses its native technique to provide continuous
availability of services running on VMs even if a physical compute system or a
hypervisor fails.
Information Storage and Management (ISM) v4
Page 540
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
In this implementation, a live instance (a secondary VM) of a primary VM is created
on another compute system. The primary and secondary VMs exchange
heartbeats. If the primary VM fails due to hardware failure, the clustering enables
failover to the secondary VM immediately. After a transparent failover occurs, a
new secondary VM is created and redundancy is reestablished.
The hypervisor running the primary VM as shown in the illustration captures the
sequence of events for the primary VM. This includes instructions from the virtual
I/O devices, virtual NICs, and so on. Then it transfers these sequences to the
hypervisor running on another compute system. The hypervisor running the
secondary VM receives these event sequences and sends them to the secondary
VM for execution.
The primary and the secondary VMs share the same storage, but all output
operations are performed only by the primary VM. A locking mechanism ensures
that the secondary VM does not perform write operations on the shared storage.
The hypervisor posts all events to the secondary VM at the same execution point
as they occurred on the primary VM. This way, these VMs “play” the same set of
events and their states are synchronized with each other.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 541
Business Continuity Fault Tolerance Lesson
Network Fault Tolerance Mechanisms
A short-time network interruption could impact plenty of services running in a data
center environment. So, the network infrastructure must be fully redundant and
highly available with no single points of failure. The following techniques provide
fault tolerance mechanism against link failure:
Link Aggregation
FC Switch
Link Aggregation
FC Switch

Combines links between two switches and also between a switch and a node

Enables network traffic failover in the event of a link failure in the aggregation
NIC Teaming
Physical Compute System
Load Distribution and
Failover
Teaming Software
Physical Switch
Logical NIC
Physical NIC
Information Storage and Management (ISM) v4
Page 542
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson

Groups NICs so that they appear as a single, logical NIC to the operation
system or hypervisor

Provides network traffic failover in the event of a NIC/link failure

Distributes network traffic across NICs
Multipathing



Enables a compute system to
use multiple paths for
transferring data to a LUN
Enables failover by redirecting
I/O from a failed path to
another active path
Performs load balancing by
distributing I/O across active
paths
Elastic Load Balancing

Enables dynamic distribution of
application and client I/O traffic

Dynamically scales resources
(VM instances) to meet traffic
demands

Physical Compute System
Provides fault tolerance
capability by detecting the
unhealthy VM instances and
automatically redirects the I/Os
to other healthy VM instances
Hypervisor
Multipathing Software
HBA1
HBA2
Path1
Path3
Path2
Path4
FC Switch
FC Switch
SC2
SC1
LUN
Storage
System
Notes
A short-time network interruption could impact plenty of services running in a data
center environment. So, the network infrastructure must be fully redundant and
highly available with no single points of failure. The techniques such as link
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 543
Business Continuity Fault Tolerance Lesson
aggregation, NIC teaming, multipathing, and load balancing provide fault tolerance
mechanism against link failure.

Link aggregation combines two or more network links into a single logical link,
called port channel, yielding higher bandwidth than a single link could provide.
Link aggregation enables distribution of network traffic across the links and
traffic failover if there is a link failure. If a link in the aggregation is lost, all
network traffic on that link is redistributed across the remaining links.

NIC teaming groups NICs so that they appear as a single, logical NIC to the OS
or hypervisor. NIC teaming provides network traffic failover to prevent
connectivity loss if there is a NIC failure or a network link outage. Sometimes,
NIC teaming enables aggregation of network bandwidth of individual NICs. The
bandwidth aggregation facilitates distribution of network traffic across NICs in
the team.
Multipathing enables organizations to meet aggressive availability and performance
service levels. It enables a compute system to use multiple paths for transferring
data to a LUN on a storage system. Multipathing enables automated path failover.
It eliminates the possibility of disrupting an application or service due to the failure
of an adapter, cable, port, and so on. When path failover happens all outstanding
and subsequent I/O requests are automatically directed to alternative paths.
To use multipathing, multiple paths must exist between the compute and the
storage systems. Each path can be configured as either active or standby. If one or
more active paths fail then standby paths become active. If an active path fails, the
multipathing process detects the failed path and then redirects I/Os of the failed
path to another active path.
Multipathing can be an integrated operating system and hypervisor function. It can
also be a third party software module that can be installed to the operating system
or hypervisor. The illustration shows a configuration where four paths between the
physical compute system (with dual-port HBAs) and the LUN enable multipathing.
Multipathing can perform load balancing by distributing I/O across all active paths.
Elastic load balancing enables dynamic distribution of application and client I/O
traffic among VM instances. It dynamically scales resources (VM instances) to
meet traffic demands. Load balancer provides fault tolerance capability by
detecting the unhealthy VM instances and automatically redirects the I/Os to other
healthy VM instances.
Information Storage and Management (ISM) v4
Page 544
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 545
Business Continuity Fault Tolerance Lesson
Storage Fault Tolerance Mechanisms
Data centers comprise storage systems with a large number of disk drives, and
solid state drives. This storage systems support various applications and services
running in the environment. The failure of these drives could result in data loss and
information unavailability. The greater the number of drives in use the greater is the
probability of a drive failure.
The following techniques provide data protection in the event of drive failure:
RAID

Provides data protection against one or two drive failures
– Example: RAID 6 (dual distributed parity), where data is protected against
two disk failures
A1
A2
Ap
Aq
B1
Bp
Bq
B2
Cp
Cq
C1
C2
RAID6 - Dual Distributed Parity
Erasure Coding
Erasure Coding: Provides space-optimal data redundancy to protect data loss
against multiple drive failure
Dynamic Disk Sparing
Dynamic Disk Sparing

Automatically replaces a failed drive with a spare drive to protect against data
loss

Multiple spare drives can be configured to improve availability
Information Storage and Management (ISM) v4
Page 546
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Storage Virtualization
Storage Resiliency using Virtualization
VM
VM
Hypervisor
Virtual Volume
I/Os
Virtualization
Appliance
Storage Pool
SAN
LUN
LUN
Storage
System
Mirror Legs

Virtual volume is created using virtualization appliance

Each I/O to the volume is mirrored to the LUNs on the storage systems
Storage
System
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 547
Business Continuity Fault Tolerance Lesson

Virtual volume is continuously available to compute system

Even if one of the storage systems is unavailable due to failure
The illustration provides an example of a virtual volume that is mirrored between
LUNs of two different storage systems. Each I/O to the virtual volume is mirrored to
the underlying LUNs on the storage systems. If one of the storage systems incurs
an outage due to failure or maintenance, the virtualization appliance will be able to
continue processing I/O on the surviving mirror leg. Upon restoration of the failed
storage system, the data from the surviving LUN is resynchronized to the
recovered leg. This method provides protection and high availability for critical
services if there is a storage system failure.
Notes
Dynamic disk sparing is a fault tolerance mechanism that refers to a spare drive
which automatically replaces a failed disk drive by taking the identity of it. A spare
drive should be large enough to accommodate data from a failed drive. Some
systems implement multiple spare drives to improve data availability.
In dynamic disk sparing, when the recoverable error rates for a disk exceed a
predetermined threshold, the disk subsystem tries to copy data from the failing disk
to the spare drive automatically. If this task is completed before the damaged disk
fails, the subsystem switches to the spare disk and marks the failing disk as
unusable. Otherwise, it uses parity or the mirrored disk to recover the data.
Storage resiliency can be achieved by using a storage virtualization appliance. A
virtualization layer that is created at SAN using virtualization appliance abstracts
the identity of physical storage devices and creates a storage pool from
heterogeneous storage systems. Virtual volume is created from the storage pool
and assigned to the compute system.
Instead of being directed to the LUNs on the individual storage systems, the
compute systems are directed to the virtual volume provided by the virtualization
layer
Information Storage and Management (ISM) v4
Page 548
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Fault Tolerance at Site-Level – Availability Zones
An availability zone is a location with its own set of resources and isolated from
other zones.A zone can be an entire data center or a part of the data center

Enables running multiple service instances within and across zones to survive
data center or site failure

If there is an outage, the service should seamlessly failover across the zones
Zones within a particular region are typically connected through low-latency
network for enabling faster service failover.
Notes
An important high availability design best practice is to create availability zones. An
availability zone is a location with its own set of resources and isolated from other
zones. Therefore, a failure in one zone will not impact other zones. A zone can be
a part of a data center or may even be an entire data center.
This method provides redundant computing facilities on which applications or
services can be deployed. Organizations can deploy multiple zones within a data
center (to run multiple instances of a service), so that if one of the zones incurs an
outage due to some reason, the service can be failed over to the other zone.
For example, if two compute systems are deployed, one in zone A and the other in
zone B, and then the probability that both go down simultaneously due to an
external event is low. This simple strategy enables the organization to construct
highly reliable web services by placing compute systems into multiple zones. So
the failure of one zone does not disrupt the service, or at the least, enable to rapidly
reconstruct the service in the second zone.
Organizations also deploy multiple zones across geographically dispersed data
centers (to run multiple instances of a service). This method helps the services to
survive even if the failure is at the data center level.
It is also important that there should be a mechanism that enables seamless
(automated) failover of services running in one zone to another. Automated failover
provides a reduced RTO when compared to the manual process. A failover process
also depends upon other capabilities, including replication and live migration
capabilities, and reliable network infrastructure between the zones.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 549
Business Continuity Fault Tolerance Lesson
Information Storage and Management (ISM) v4
Page 550
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Fault Tolerance at Site-Level – Example
High availability can be achieved by moving services across zones that are located
in different locations without user interruption. The services can be moved across
zones by implementing stretched cluster.
A stretched cluster is a cluster with compute systems in different remote locations
provide DR capability if there is a disaster in one of the data centers. Stretched
clusters are typically built as a way to create active/active zones to provide high
availability and enable dynamic workload balancing across zones.
Zone A
Zone B
VM
Compute
System
VM
VM
VM
I/Os
Compute
System
Hypervisor
Stretched Cluster
Hypervisor
I/Os
FC SAN
FC SAN
Virtual Volume
Virtualization
Appliance
Virtualization
Appliance
FC/IP
Storage Pool
Virtualization
Layer
Storage
System
LUN
LUN
Storage
System
Notes
The illustration also shows that a virtual volume is created from the federated
storage resources across zones. The virtualization appliance has the ability to
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 551
Business Continuity Fault Tolerance Lesson
mirror the data of a virtual volume between the LUNs located in two different
storage systems at different locations.
Each I/O from a host to the virtual volume is mirrored to the underlying LUNs on the
storage systems. If an outage occurs at one of the data centers, for example at
zone A, then the running VMs at zone A can be restarted at Zone B without
impacting the service availability.
This setup also enables accessing the storage even if one of the storage systems
is unavailable. If storage system at zone A is unavailable, then the hypervisor
running there still accesses the virtual volume. The hypervisor can access the data
from the available storage system at zone B.
Information Storage and Management (ISM) v4
Page 552
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
Resilient Application Overview

Applications have to be designed to deal with IT resource’s failure to guarantee
the required availability

Fault resilient applications have logic to detect and handle transient fault
conditions to avoid application downtime

Examples of key application design strategies for improving availability:
 Graceful degradation of application functionality
 Retry logic in application code
 Persistent application state model
Notes
Today, organizations typically build their IT infrastructure using commodity systems
to achieve scalability and keep hardware costs down. In this environment, it is
assumed that some components will fail. Therefore, in the design of an application
the failure of individual resources often has to be anticipated to ensure an
acceptable availability of the application.
A reliable application properly manages the failure of one or more modules and
continues operating properly. If a failed operation is retried a few milliseconds later,
the operation may succeed. These types of error conditions are called as transient
faults. Fault resilient applications have logic to detect and handle transient fault
conditions in order to avoid application downtime.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 553
Business Continuity Fault Tolerance Lesson
Key Application Design Strategies for Improving Availability
Graceful Degradation

Application maintains limited functionality even when some of the modules or
supporting services are not available

Unavailability of certain application components or modules should not bring
down the entire application
Fault Detection and Retry Logic

Refers to a mechanism that implements a logic in the code of an application to
improve the availability

To detect and retry the service that is temporarily down; may result in
successful restore of service
Persistent Application State Model

Application state information is stored out of the memory

Stored in a data repository

If an instance fails, the state information is still available in the repository
Notes
Graceful degradation refers to the ability of an application to maintain limited
functionality even when some of the components, modules, or supporting services
are not available. The purpose of graceful degradation of application functionality is
to prevent the complete failure of a business application.
For example, consider an eCommerce application that consists of modules such as
product catalog, shopping cart, order status, order submission, and order
Information Storage and Management (ISM) v4
Page 554
© Copyright 2019 Dell Inc.
Business Continuity Fault Tolerance Lesson
processing. Assume that due to some problem the payment gateway is
unavailable. It is impossible for the order processing module of the application to
continue. If the application is not designed to handle this scenario, the entire
application might go offline.
However, in this same scenario, it is still possible to make the product catalog
module available to consumers, to view the product catalog. The application could
also enable one to place the order and move it into the shopping cart. This method
provides the ability to process the orders when the payment gateway is available or
after failing over to a secondary payment gateway.
A key mechanism in an application design is to implement retry logic within a code
to handle a service that is temporarily down. When applications use other services,
errors can occur because of temporary conditions such as intermittent service,
infrastructure-level faults, or network issues. Often, this form of problem can be
solved by retrying the operation a few milliseconds later, and the operation may
succeed.
To implement the retry logic in an application, it is important to detect and identify
that particular exception which is likely to be caused by a transient fault condition. A
retry strategy must be defined to state how many retries can be attempted before
deciding that the fault is not transient.
In a stateful application model, the session state information of an application (for
example user ID, selected products in a shopping cart, and so on) is stored in
compute system memory. However, the information that is stored in the memory
can be lost if there is an outage with the compute system where the application
runs.
In a persistent application state model, the state information is stored out of the
memory and is stored in a repository (database). If a VM running the application
instance fails, the state information is still available in the repository. A new
application instance is created on another VM which can access the state
information from the database and resume the processing.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 555
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC PowerPath

VMware HA

VMware FT
Information Storage and Management (ISM) v4
Page 556
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts In Practice
Concepts in Practice
Dell EMC PowerPath

Host-based multipathing software

Provides path failover and load-balancing functionality

Automatic detection and recovery from host-to-array path failures

PowerPath/VE software enables optimizing virtual environments with
PowerPath multipathing features
The video is located at
https://edutube.emc.com/Player.aspx?vno=YzeGufRuF1rmd9Sw11ku3A
A family of software products that ensures consistent application availability and
performance across I/O paths on physical and virtual platforms. It provides
automated path management and tools that enable to satisfy aggressive SLAs
without investing in more infrastructure.
Dell EMC PowerPath/VE is compatible with VMware vSphere and Microsoft HyperV-based virtual environments. It can be used together with Dell EMC PowerPath to
perform the following functions in both physical and virtual environments:

Standardize Path Management: Optimize I/O paths in physical and virtual
environments (PowerPath/VE) and cloud deployments

Optimize Load Balancing: Adjust I/O paths to dynamically rebalance your
application environment for peak performance

Automate Failover/Recovery: Define failover and recovery rules that route
application requests to alternative resources in the event of component failures
or user errors
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 557
Concepts in Practice Lesson
Concepts in Practice
VMware HA

Provides high availability for applications running in virtual machines

If there is a fault in a physical compute system, then the affected VMs are
automatically restarted on other compute systems
VMware FT

Provides continuous availability for application in the event of server failure

Creates a live shadow instance of a VM that is in virtual lockstep with the
primary instance

FT eliminates even the smallest chance of data loss or disruption
VMware HA
VMware HA provides high availability for applications running in VMs. If there is a
fault in a physical compute system, then the affected VMs are automatically
restarted on other compute systems.
VMware HA minimizes unplanned downtime and IT service disruption while
eliminating the need for dedicated standby hardware and installation of additional
software.
VMware FT
VMware FT provides continuous availability for applications in the event of server
failures. It creates a live shadow instance of a VM that is in virtual lockstep with the
primary VM instance.
VMware FT is used to prevent application disruption due to hardware failures. The
downtime that is associated with mission-critical applications can be expensive and
disruptive to businesses. By enabling instantaneous failover between the two
Information Storage and Management (ISM) v4
Page 558
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
instances in the event of hardware failure, FT eliminates even the smallest chance
of data loss or disruption.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 559
Concepts in Practice Lesson
Assessment
1. Which defines the amount of data loss that a business can endure?
A. RTO
B. RPO
C. Persistent state model
D. Availability zone
2. Which refers to the ability of an application to maintain limited functionality even
when some of the components, modules, or supporting services are not
available?
A. Graceful degradation
B. Retry logic
C. Partial mesh topology
D. Core-edge topology
Information Storage and Management (ISM) v4
Page 560
© Copyright 2019 Dell Inc.
Summary
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 561
Data Protection Solutions
Introduction
This module presents need for backup, various backup methods and deduplication
implementation. This module also focuses on different replication types, data
archiving solution, and data migration solution.
Upon completing this module, you will be able to:





Explain various backup methods
Describe deduplication
Explain different replication methodsü
Describe data archiving
Explain data migration
Information Storage and Management (ISM) v4
Page 562
© Copyright 2019 Dell Inc.
Replication Lesson
Replication Lesson
Introduction
This lesson presents the primary uses of replica, and characteristics of replica. This
lesson also focuses on replication types.
This lesson covers the following topics:

Primary uses of replica

Characteristics of replica

Types of replication
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 563
Replication Lesson
Replication
Video: Replication Overview
The video is located at
https://edutube.emc.com/Player.aspx?vno=IJ7983uhVoaiWLfvjhttlg
Information Storage and Management (ISM) v4
Page 564
© Copyright 2019 Dell Inc.
Replication Lesson
Introduction to Data Replication
Definition: Data Replication
A process of creating an exact copy (replica) of the data to ensure
business continuity in the event of a local outage or disaster.

Replicas are used to restore and restart operations if data loss occurs

Data can be replicated to one or more locations based on the business
requirements
Data Center A
Data
Replication
Replica
Data Center B
Servers
Connectivity
Data
Replication
Storage
Primary Storage
Replica
Cloud
Data Replication
to Cloud
Data Replication
Notes
Data is one of the most valuable assets of any organization. It is being stored,
mined, transformed, and used continuously. It is a critical component in the
operation and function of organizations. Outages, whatever may be the cause, are
costly, and customers are always concerned about data availability. Safeguarding
and keeping the data highly available are some of the top priorities of any
organization.
To avoid disruptions in business operations, it is necessary to implement data
protection technologies in a data center. A data replication solution is one of the
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 565
Replication Lesson
key data protection solutions that enables organizations to achieve business
continuity, high availability, and data protection.
Data replication is the process of creating an exact copy (replica) of data. If a data
loss occurs, then the replicas are used to restore and restart operations. For
example, if a production VM goes down and then the replica VM can be used to
restart the production operations with minimum disruption. Based on business
requirements, data can be replicated to one or more locations.
For example, data can be replicated within a data center, between data centers,
from a data center to a cloud, or between clouds.In a replication environment, a
compute system accessing the production data from one or more LUNs on storage
system is called a production compute system. These LUNs are known as source
LUNs, production LUNs, or the source. A LUN on which the production data is
replicated to is called the target LUN or the target or replica.
Information Storage and Management (ISM) v4
Page 566
© Copyright 2019 Dell Inc.
Replication Lesson
Primary Uses of Replicas
Replicas are created for various purposes which include the following:
Replication
Can act as a source for backup
Replication
Can be used to restart business
operations or to recover the data
Replication
Used for running decision support
activities
Data
Source
Replication
Used for testing applications
Replication
Data migration
Replica
Notes
Alternative Source for Backup
Under normal backup operations, data is read from the production LUNs and
written to the backup device. This places an extra burden on the production
infrastructure because production LUNs are simultaneously involved in production
operations and servicing data for backup operations.
To avoid this situation, a replica can be created from production LUN and it can be
used as a source to perform backup operations. This method alleviates the backup
I/O workload on the production LUNs.
Fast Recovery and Restart
For critical applications, replicas can be taken at short, regular intervals. This
enables fast recovery from data loss. If a complete failure of the source LUN
occurs, the replication solution enables to restart the production operation on the
replica. This approach reduces the RTO.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 567
Replication Lesson
Decision-Support Activities
Running reports using the data on the replicas greatly reduces the I/O burden on
the production device.
Testing Platform
Replicas are also used for testing new applications or upgrades.
For example, an organization may use the replica to test the production application
upgrade. If the test is successful, the upgrade may be implemented on the
production environment.
Data Migration
Another use for a replica is data migration. Data migrations are performed for
various reasons such as migrating from a smaller capacity LUN to one of a larger
capacity.
Information Storage and Management (ISM) v4
Page 568
© Copyright 2019 Dell Inc.
Replication Lesson
Replica Characteristics and Types
Replica Characteristics
Replica Types
Recoverability/Restartability
Point-in-Time (PIT)

Replica could restore data to the source device


Restart business operation from replica
Nonzero RPO
Consistency
Continuous

Ensures the usability of a replica


Replica must be consistent with the source
Near-zero RPO
Notes
A replica should have the following characteristics:
Recoverability
Enables restoration of data from the replicas to the source if data
loss occurs.
Restartability
Enables restarting business operations using the replicas.
Consistency
Replica must be consistent with the source so that it is usable for
both recovery and restart operations.
For example, if a service running on a primary data center is to fail
over to remote site due to disaster. There must be a consistent
replica available at that site. So, ensuring consistency is the
primary requirement for all the replication technologies.Replicas
can either be point-in-time (PIT) or continuous and the choice of
replica ties back into RPO.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 569
Replication Lesson
PIT replica
The data on the replica is an identical image of the production at
some specific timestamp.
For example, a replica of a file system is created at 4:00 PM on
Monday. This replica would then be referred to as the Monday
4:00 PM PIT copy. The RPO maps to the time when the PIT was
created to the time when any kind of failure on the production
occurred. If there is a failure on the production at 8:00 PM and
there is a 4:00 PM PIT available, the RPO would be 4 hours (84=4). To minimize RPO, take periodic PITs.
Continuous
replica
The data on the replica is in-sync with the production data always.
The objective with any continuous replication is to reduce the
RPO to zero or near-zero.
Information Storage and Management (ISM) v4
Page 570
© Copyright 2019 Dell Inc.
Replication Lesson
Types of Replication
Replication can be classified into two major categories:
Local Replication

Refers to
replicating data
within the same
location
 Within a data
center in
compute-based
replication
Storage
System
Data is replicated within a storage
system in a storage-based
replication
Storage
System
Data is replicated within a data
center from one system to another in
a compute-based replication
Data Center
 Within a
storage system in storage system-based replication

Typically used for operational restore of data if there is a data loss
Remote Replication

Refers to
replicating data
to remote
locations
(locations can be
geographically
dispersed)
Data is replicated to
remote data center
Storage System
Storage System
Data Center A
Data Center B

Data can be
synchronously or asynchronously replicated

Helps to mitigate the risks associated with regional outages

Enables organizations to replicate the data to cloud for DR purpose
Notes
Local replication is the process of replicating data within the same storage system
or the same data center.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 571
Replication Lesson
Local replicas help to restore the data if there is a data loss or enable restarting the
application immediately to ensure business continuity.
Remote replication is the process of replicating data to remote locations (locations
can be geographically dispersed).
Remote replication helps organizations to mitigate the risks that are associated with
regional outages resulting from natural or human-made disasters. During disasters,
the services can be moved to a remote location to ensure continuous business
operation.
Remote replication also enables organizations to replicate their data to the cloud
for DR purpose. In a remote replication, data can be synchronously or
asynchronously replicated.
Information Storage and Management (ISM) v4
Page 572
© Copyright 2019 Dell Inc.
Replication Lesson
Video: Storage-Based Replication
The video is located at
https://edutube.emc.com/Player.aspx?vno=DuaE7ghKQBfkz+5UGLQiDg
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 573
Replication Lesson
Local Replication: VM Snapshot

A VM snapshot preserves the state and data of a VM at a specific PIT
– The state includes the VM's power state, for example: powered-on,
powered-off, or suspended

The data includes all the files that make up the VM
– This includes disks, memory, and other devices, such as virtual network
interface cards
– This VM snapshot is useful for quick restore of a VM
For example:

An administrator can create a snapshot of a VM, make changes such as
applying patches and software upgrades to the VM

If anything goes wrong, the administrator can restore the VM to its previous
state using the VM snapshot

The hypervisor provides an option to create and manage multiple snapshots

Taking multiple snapshots provide several restore points for a VM

While more snapshots improve the resiliency of the infrastructure, it is important
to consider the storage space they consume
Notes
When a snapshot is created for a VM, a child virtual disk (delta disk file) is created
from the base image or parent virtual disk. The snapshot mechanism prevents the
guest operating system from writing to the base image or parent virtual disk.
Instead it directs all writes to the delta disk file. Successive snapshots generate a
new child virtual disk from the last child virtual disk in the chain. Snapshots hold
only changed blocks.
Sometimes it may be required to retain a snapshot for longer period. It must be
noted that larger snapshots take longer time to commit and may impact the
performance. Source (parent VM) must be healthy in order to use snapshot for roll
back.
Information Storage and Management (ISM) v4
Page 574
© Copyright 2019 Dell Inc.
Replication Lesson
Local Replication: VM Snapshot Example

Child virtual disks store all the changes that are made to the parent VM after
snapshots are created

When committing snapshot 3, the data on child virtual disk file 1 and 2 are
committed prior to committing data on child virtual disk 3 to the parent virtual
disk file
 After committing the data, the child virtual disk 1, 2, and 3 are deleted
 However, while rolling back to the snapshot 1, child disk file 1 is retained
and the snapshots 2 and 3 are discarded
VM
VM writes here
Snapshot 3 (Child
Virtual Disk 3)
Changed blocks
of snapshot 2
and base image
Snapshot 2 (Child
Virtual Disk 2)
Changed blocks
of snapshot 1
Snapshot 1 (Child
Virtual Disk 1)
Changed blocks
of base image
Base Image (Parent
Virtual Disk)
VM virtual disk
Storage
Notes
Consider an example in which three snapshots of a VM are created as shown on
the slide. In this example, child virtual disk 1 stores all the changes that are made
to the parent VM after snapshot 1 is created. Similarly, child virtual disk 2 and child
virtual disk 3 store all the changes after snapshot 2 and snapshot 3 are created
respectively. When committing snapshot 3 for the VM, the data on child virtual disk
file 1 and 2 are committed prior to committing data on child virtual disk 3 to the
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 575
Replication Lesson
parent virtual disk file. After committing the data, the child virtual disk 1, child virtual
disk 2, and child virtual disk 3 are deleted. However, while rolling back to the
snapshot 1(PIT), child disk file 1 is retained and the snapshots 2 and 3 are
discarded.Sometimes it may be required to retain a snapshot for longer period. It
must be noted that larger snapshots take longer time to commit and may impact
the performance. Source (parent VM) must be healthy in order to use snapshot for
roll back.
Information Storage and Management (ISM) v4
Page 576
© Copyright 2019 Dell Inc.
Replication Lesson
Local Replication: Storage System-Based Snapshot - RoW

Redirects new writes that are
destined for the source LUN to
a reserved LUN in the storage
pool
VM
VM
Target
Compute
System
Hypervisor
VM

Replica (snapshot) still points
to the source LUN
 All reads from replica are
served from the source LUN
Source
Compute
System
Writes
VM
Hypervisor
All reads from replica
are served from
source
Reads
Notes
Source
Storage system-based snapshot is
a space optimal pointer-based
virtual replication. At the time of
replication session activation, the
target (snapshot) contains pointers
to the location of the data on the
source. The snapshot does not
contain data at any time. The
snapshot is known as a virtual
replica.
Snapshot
New data written
to new location
Reserved LUN
Storage Pool
The snapshot is immediately accessible after the replication session activation.
Snapshot is typically recommended when the changes to the source are less than
30 percent. Multiple snapshots can be created from the same source LUN for
various business requirements.
Some snapshot software provides the capability of automatic termination of a
snapshot upon reaching the expiration date. This approach is useful where a rolling
snapshot might be taken and then automatically removed after its time of
usefulness has passed. The unavailability of the source device invalidates the data
on the target. The storage system-based snapshot uses a Redirect on Write (RoW)
mechanism.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 577
Replication Lesson
Some pointer-based virtual replication implementations use redirect on write
technology (RoW). RoW redirects new writes that are destined for the source LUN
to a reserved LUN in the storage pool. In RoW, a new write from source compute
system is written to a new location (redirected) inside the pool. The original data
remains where it is, and is untouched by the RoW process. In a RoW snapshot, the
original data remains where it is, and is therefore read from the original location on
the source LUN.
Information Storage and Management (ISM) v4
Page 578
© Copyright 2019 Dell Inc.
Replication Lesson
Local Replication: Clone

Cloning provides the ability to create fully populated point-in-time copies of
LUNs within a storage system or create a copy of an existing VM

Clone of a storage volume
 Initial synchronization is performed between the source LUN and the replica
(clone)
 Changes made to both the source and the replica can be tracked at some
predefined granularity

VM clone
 Clone is a copy of an existing virtual machine (parent VM)
o The clone VM’s MAC address is different from the parent VM
 Typically clones are deployed when many identical VMs are required
o Reduces the time that is required to deploy a new VM
Notes
Cloning provides the ability to create fully populated point-in-time copies of LUNs
within a storage system or create a copy of an existing VM.
Clone of a storage volume:

When the replication session is started, an initial synchronization is performed
between the source LUN and the replica (clone). Synchronization is the process
of copying data from the source LUN to the clone. During synchronization
process, the replica is not available for any compute system access. Once the
synchronization is completed, the replica is exactly same as source LUN. The
replica can be detached from the source LUN. It can be made available to
another compute system for business operations. Subsequent synchronizations
involve only a copy of any data that has changed on the source LUN since the
previous synchronization.

Typically after detachment, changes made to both the source and replica can
be tracked at some predefined granularity. This approach enables incremental
resynchronization (source to target) or incremental restore (target to source).
The clone must be the same size as the source LUN.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 579
Replication Lesson
VM Clone:

A VM clone is a copy of an existing VM. The existing VM is called the parent of
the clone. When the cloning operation completes, the clone becomes a
separate VM. The changes made to a clone do not affect the parent VM.
Changes made to the parent VM do not appear in a clone. A clone's MAC
address is different from that of the parent VM.

In general, installing a guest operating system and applications on a VM is a
time consuming task. With clones, administrators can make many copies of a
virtual machine from a single installation and configuration process. For
example, in an organization, the administrator can clone a VM for each new
employee, with a suite of preconfigured software applications.
Information Storage and Management (ISM) v4
Page 580
© Copyright 2019 Dell Inc.
Replication Lesson
Remote Replication: Synchronous

Write is committed to both the source and the remote replica before it is
acknowledged to the compute system

Enables to restart business operations at a remote site with zero data loss;
Provides near zero RPO
VM
Production
Compute
System
VM
1.The write I/O is received from production compute
system into cache of source and placed in queue
Hypervisor
1
2.The write I/O is transmitted to the cache of the target
storage
4
2
Storage
(Target)
Storage
(Source)
4.Source storage system sends an acknowledgment back
to the production compute system
3
Source Site
3.Receipt acknowledgment is provided by target
storage back to cache of the source
Remote Site
Notes
Storage-based remote replication solution can avoid downtime by enabling
business operations at remote sites. Storage-based synchronous remote
replication provides near zero RPO where the target is identical to the source
always.
In synchronous replication, writes must be committed to the source and the remote
target prior to acknowledging “write complete” to the production compute system.
Additional writes on the source cannot occur until each preceding write has been
completed and acknowledged.
This approach ensures that data is identical on the source and the target at all
times. Further, writes are transmitted to the remote site exactly in the order in which
they are received at the source. Write ordering is maintained and it ensures
transactional consistency when the applications are restarted at the remote
location. As a result, the remote images are always restartable copies.

Note: Application response time is increased with synchronous remote
replication. Since, writes must be committed on both the source and the target
before sending the “write complete” acknowledgment to the compute system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 581
Replication Lesson
The degree of impact on response time depends primarily on the distance and
the network bandwidth between sites. If the bandwidth provided for
synchronous remote replication is less than the maximum write workload, there
will be times during the day when the response time might be excessively
elongated, causing applications to time out. The distances over which
synchronous replication can be deployed depend on the application’s capability
to tolerate the extensions in response time. Typically synchronous remote
replication is deployed for distances less than 200 kilometers (125 miles)
between the two sites.
Information Storage and Management (ISM) v4
Page 582
© Copyright 2019 Dell Inc.
Replication Lesson
Remote Replication: Asynchronous
A write is committed to the source and immediately acknowledged to the compute
system:

Data is buffered at the source and sent to the remote site periodically

Applications write response time is not dependent on the latency of the link

Replica is behind the source by a finite amount (finite RPO)
VM
Production
Compute
System
VM
1.The write I/O is received from production compute system
into cache of source and placed in queue
Hypervisor
1
2. Receipt acknowledgment is provided by source storage
back to production compute system
2
3
Storage
(Target)
Storage
(Source)
3. The write I/O is transmitted to the cache of the target
storage
4. Target acknowledges back to source
4
Source Site
Remote Site
Notes
It is important for an organization to replicate data across geographical locations to
mitigate the risk involved during disaster. If the data is replicated (synchronously)
between sites and the disaster strikes, then there would be a chance that both the
sites may be impacted. This leads to data loss and service outage.
Replicating data across sites which are 1000s of kilometers apart would help
organization to face any disaster. If a disaster strikes at one of the regions then the
data would still be available in another region. The service could move to the
location. Asynchronous replication enables to replicate data across sites which are
1000s of kilometers apart.
In asynchronous remote replication, a write from a production compute system is
committed to the source and immediately acknowledged to the compute system.
Asynchronous replication also mitigates the impact to the application’s response
time because the writes are acknowledged immediately to the compute system.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 583
Replication Lesson
This method enables replicating data over distances of up to several thousand
kilometers between the source site and the secondary site (remote locations). In
this replication, the required bandwidth can be provisioned equal to or greater than
the average write workload.
In asynchronous replication, compute system writes are collected into buffer (delta
set) at the source. This delta set is transferred to the remote site in regular
intervals. Adequate buffer capacity should be provisioned to perform asynchronous
replication. Some storage vendors offer a feature called delta set extension, which
enables to offload delta set from buffer (cache) to specially configured drives. This
feature makes asynchronous replication resilient to the temporary increase in write
workload or loss of network link.
In asynchronous replication, RPO depends on the size of the buffer, the available
network bandwidth, and the write workload to the source. This replication can take
advantage of locality of reference (repeated writes to the same location). If the
same location is written multiple times in the buffer prior to transmission to the
remote site, only the final version of the data is transmitted. This feature conserves
link bandwidth.
Information Storage and Management (ISM) v4
Page 584
© Copyright 2019 Dell Inc.
Replication Lesson
Remote Replication: Multisite

Data from source site is replicated to multiple remote sites for DR purpose
 Disaster recovery protection is always available if any one-site failure occurs

Mitigates the risk in two-site replication
 No DR protection after source or remote site failure
Remote Site
VM
VM
Production
Compute System
Hypervisor
Storage
(Target 2)
Asynchronous
Asynchronous with Differential
Resynchronization
Bunker Site
Storage (Source)
Synchronous
Storage
(Target 1)
Source Site
Notes
In a two-site synchronous replication, the source and target sites are usually within
a short distance. If a regional disaster occurs, both the source and the target sites
might become unavailable. This can lead to extended RPO and RTO. Since the
last known good copy of data would need to come from another source, such as an
offsite tape. A regional disaster will not affect the target site in a two-site
asynchronous replication since the sites are typically several hundred or several
thousand kilometers apart. If the source site fails, production can be shifted to the
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 585
Replication Lesson
target site. However, there is no further remote protection of data until the failure is
resolved.
Multisite replication mitigates the risks that are identified in two-site replication. In a
multisite replication, data from the source site is replicated to two or more remote
sites. The illustration provides an example of a three-site remote replication
solution. In this approach, data at the source is replicated to two different storage
systems at two different sites. The source-to-bunker site (target 1) replication is
synchronous with a near-zero RPO. The source-to-remote site (target 2) replication
is asynchronous with an RPO in the order of minutes. The key benefit of this
replication is the ability to fail over to either of the two remote sites in the case of
source-site failure.
Disaster recovery protection is always available if any one-site failure occurs.
During normal operations, all three sites are available and the production workload
is at the source site. At any given instance, the data at the bunker and the source is
identical. The data at the remote site is behind the data at the source and the
bunker. The replication network links between the bunker and the remote sites are
in place but will not be in use. The difference in the data between the bunker and
the remote sites is tracked. If a source site disaster occurs, operations can be
resumed at the bunker or the remote sites with incremental resynchronization
between these two sites.
Information Storage and Management (ISM) v4
Page 586
© Copyright 2019 Dell Inc.
Replication Lesson
Video: Network-Based Replication
The video is located at
https://edutube.emc.com/Player.aspx?vno=tdtXEqmgsWqD0pvctet7Rg
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 587
Replication Lesson
Continuous Data Protection (CDP)

Network-based replication solution

CDP provides the ability to restore data and VMs to any previous PIT

Supports heterogeneous compute and storage platforms

Supports both local and remote replication
 Data can also be replicated to more than two sites (multisite)

Supports WAN optimization techniques to reduce bandwidth requirements
Notes
Continuous data protection (CDP) is a network-based replication solution that
provides the capability to restore data and VMs to any previous PIT.
Traditional data protection technologies offer a limited number of recovery points. If
a data loss occurs, the system can be rolled back only to the last available recovery
point. CDP tracks all the changes to the production volumes and maintains
consistent point-in-time images. This makes the CDP to restore data to any
previous PIT.
CDP supports both local and remote replication of data and VMs to meet
operational and disaster recovery respectively. In a CDP implementation, data can
be replicated to more than two sites using synchronous and asynchronous
replication. CDP supports various WAN optimization techniques (deduplication,
compression). These techniques reduce bandwidth requirements, and also
optimally use the available bandwidth.
Information Storage and Management (ISM) v4
Page 588
© Copyright 2019 Dell Inc.
Replication Lesson
Key CDP Components
The following are key CDP components:
Journal Volume

Contains all the data that has changed from the time the replication session
started to the production volume
CDP Appliance

Intelligent hardware platform that runs the CDP software

Manages both the local and the remote replications

Appliance could also be virtual, where CDP software is running inside VMs
Write Splitter

Intercept writes to the production volume from the compute system and splits
each write into two copies

Can be implemented at the compute, fabric, or storage system
Notes
CDP uses a journal volume to store all the data that has changed on the production
volume from the time the replication session started. The journal contains the
metadata and data that enable roll back to any recovery points. The amount of
space that is configured for the journal determines how far back the recovery points
can go.
CDP also uses an appliance and a write splitter. A CDP appliance is an intelligent
hardware platform that runs the CDP software and manages local and remote data
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 589
Replication Lesson
replications. Some vendors offer virtual appliance where the CDP software is
running inside VMs.
Write splitters intercept writes to the production volume from the compute system
and split each write into two copies. Write splitting can be performed at the
compute, fabric, or storage system.
Information Storage and Management (ISM) v4
Page 590
© Copyright 2019 Dell Inc.
Replication Lesson
CDP Operations: Local and Remote Replication
The illustration provides an example of a CDP local and remote replication
operations where the write splitter is deployed at the compute system.
Compute System
VM
VM
1. Data is “split” and sent to the local CDP
appliance and production volume
2a. Writes are acknowledged back from the CDP
appliance and data is sent to journal, in turn copied to
replica
2b. Data is sequenced, compressed, and replicated to
remote appliance
3. Data is received, uncompressed, and
sequenced
Hypervisor
Write Splitter
Local CDP
Appliance
Remote CDP
Appliance
WAN/SAN
SAN
SAN
5.Data is copied to the remote
replica
4.Data is written to the journal
Production Volume
Local Replica
Journal
Source Site
Journal
Remote Replica
Remote Site
Notes
Typically the replica is synchronized with the source, and then the replication
process starts. After the replication starts, all the writes from the compute system to
the source (production volume) are split into two copies. One copy is sent to the
local CDP appliance at the source site, and the other copy is sent to the production
volume. Then the local appliance writes the data to the journal at the source site
and the data in turn is written to the local replica. If a file is accidentally deleted, or
the file is corrupted, the local journal enables organizations to recover the
application data to any PIT.
In remote replication, the local appliance at the source site sends the received write
I/O to the appliance at the remote (DR) site. Then, the write is applied to the journal
volume at the remote site. As a next step, data from the journal volume is sent to
the remote replica at predefined intervals. CDP operates in either synchronous or
asynchronous mode.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 591
Replication Lesson
In the synchronous replication mode, the application waits for an acknowledgment
from the CDP appliance at the remote site before initiating the next write. In the
case of asynchronous mode, the local CDP appliance acknowledges a write when
it is received. If there is a disaster at the source site, data can be recovered to the
required PIT. The service can be restarted at the DR site.
Information Storage and Management (ISM) v4
Page 592
© Copyright 2019 Dell Inc.
Replication Lesson
Hypervisor-based CDP
The illustration shows a CDP local replication implementation.

Protects a single or
multiple VMs locally or remotely
VM
VM
Virtual
Appliance

Enables to restore VM
to any PIT
Hypervisor

Write Splitter
Virtual appliance is
running on a hypervisor

Write splitter is
embedded in the hypervisor
SAN
Notes
Some vendors offer continuous data
protection for VMs through hypervisorSource
Local
based CDP implementation. In this
Journal
Volume
Replica
deployment, the specialized hardwareCDP - Local Replication
based appliance is replaced with virtual
appliance which is running on a
hypervisor. The write splitter is
embedded in the hypervisor. This
option protects single or multiple VMs locally or remotely and enables to restore
VMs to any PIT. The local and remote replication operations are as similar as
network-based CDP replication.
VM Disk
Files
VM Disk
Files
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 593
Backup and Recovery Lesson
Backup and Recovery Lesson
Introduction
This lesson presents the need for backup, backup architecture, backup target, and
backup operation. This lesson also focuses on backup granularity and various
backup methods.
This lesson covers the following topics:

Need for backup

Backup architecture

Backup target

Backup granularity

Backup methods
Information Storage and Management (ISM) v4
Page 594
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Backup and Recovery Overview
Backup and Recovery Overview
Definition: Backup
An additional copy of production data, which is created and retained
for the sole purpose of recovering lost or corrupted data.

Typically both application data and server configurations are backed up to
restore data and servers if there is an outage.

Businesses also implement backup solutions to comply with regulatory
requirements.

To implement a successful backup and recovery solution
 IT needs to evaluate the backup methods along with their recovery
considerations and retention requirements
Notes
Like protecting the IT infrastructure components (compute, storage, and network), it
is also critical for organizations to protect the data. Typically organizations
implement data protection solution to protect the data from accidentally deleting
files, application crashes, data corruption, and disaster. Data should be protected
at local and remote locations to ensure the availability of service.
For example: when a service is failed over to other zone (data center), the data
should be available at the destination. This approach helps to successfully failover
the service to minimize the outage. One of the key data protection solutions that
are widely implemented is backup.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 595
Backup and Recovery Lesson
A backup is an additional copy of production data, which is created and retained for
the sole purpose of recovering the lost or corrupted data. With the growing
business and the regulatory demands for data storage, retention, and availability,
organizations face the task of backing up an ever-increasing amount of data. This
task becomes more challenging with the growth of data, reduced IT budgets, and
less time available for taking backups.
Moreover, organizations need fast backup and recovery of data to meet their
service level agreements. Most organizations spend a considerable amount of time
and money protecting their application data but give less attention to protecting
their server configurations. During disaster recovery, server configurations must be
re-created before the application and data are accessible to the user.
The process of system recovery involves reinstalling the operating system,
applications, and server settings and then recovering the data. So it is important to
backup both application data and server configurations.Evaluating backup
technologies, recovery, and retention requirements for data and applications is an
essential step to ensure successful implementation of a backup and recovery
solution.
Information Storage and Management (ISM) v4
Page 596
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Video: Backup and Recovery Overview
The video is located at
http://edutube.emc.com/Player.aspx?vno=mUT1iNrePDRZHxEclMCoCA
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 597
Backup and Recovery Lesson
Backup Architecture
The role of a backup client is to gather the data that needs to backup and send it to
the storage node. The backup client can be installed on application servers, mobile
clients, and desktops. It also sends the tracking information to the backup server.
Key backup components are:

Backup client

Backup server

Storage node

Backup device (backup target)
Cloud
Backup Clients
VM
Backup Server
VM
Tracking Information
Backup Data
Tracking Information
Hypervisor
Backup Data
Backup Data
Storage Node
Backup Device
Notes
The backup server manages the backup operations and maintains the backup
catalog, which contains information about the backup configuration and backup
metadata. The backup configuration contains information about when to run
backups, which client data to be backed up, and so on. The backup metadata
contains information about the backed up data. The storage node is responsible for
organizing the client’s data and writing the data to a backup device. A storage node
controls one or more backup devices.
Information Storage and Management (ISM) v4
Page 598
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
In most implementations, the storage node and the backup server run on the same
system. Backup devices may be attached directly or through a network to the
storage node. The storage node sends the tracking information about the data that
is written to the backup device to the backup server. Typically this information is
used for recoveries. A wide range of backup targets are available such as tape,
disk, and virtual tape library. Now, organization can also back up their data to the
cloud storage. Many service providers offer backup as a service that enables an
organization to reduce its backup management overhead.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 599
Backup and Recovery Lesson
Backup Targets
Backup Target
Description
Tape Library

Tapes are portable and can be used for long term offsite
storage.

Must be stored in locations with a controlled environment

Not optimized to recognize duplicate content

Data integrity and recoverability are major issues with
tape-based backup media.

Enhanced backup and recovery performance

No inherent offsite capability

Disk-based backup appliance includes features such as
deduplication, compression, encryption, and replication to
support business objectives

Disks are emulated and presented as tapes to backup
software.

Does not require any additional modules or changes in the
legacy backup software

Provides better performance and reliability over physical
tape

Does not require the usual maintenance tasks that are
associated with a physical tape drive, such as periodic
cleaning and drive calibration
Disk Library
Virtual Tape
Library
Information Storage and Management (ISM) v4
Page 600
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Notes
A tape library contains one or more tape drives that records and retrieves data on a
magnetic tape. Tape is portable, and one of the primary reasons for the use of tape
is long-term, offsite storage. Backups that are implemented using tape devices
involve several hidden costs. Tapes must be stored in locations with a controlled
environment to ensure preservation of the media and to prevent data corruption.
Physical transportation of the tapes to offsite locations also adds management
overhead and increases the possibility of loss of tapes during offsite shipment.
The traditional backup process, using tapes, is not optimized to recognize duplicate
content. Due to its sequential data access, both backing up of data and restoring it
take more time with tape. This data access may impact the backup window and
RTO. A backup window is a period during which a production volume is available to
perform backup. Data integrity and recoverability are also major issues with tapebased backup media.
Disk density has increased dramatically over the past few years, lowering the cost
per GB. So, it became a viable backup target for organizations. When used in a
highly available configuration in a storage array, disks offer a reliable and fast
backup target medium. One way to implement a backup to disk system is by using
it as a staging area. This approach offloads backup data to a secondary backup
target such as tape after a period of time.
Some vendors offer a purpose-built, disk-based backup appliances that are
emerged as the optimal backup target solution. These systems are optimized for
backup and recovery operations, offering extensive integration with popular backup
management applications. The integrated features such as replication,
compression, encryption, and data deduplication increase the value of purposebuilt backup appliances.
Virtual tape libraries use disks as backup media. Virtual tapes are disk drives that
are emulated and presented as tapes to the backup software. Compared to
physical tapes, virtual tapes offer better performance, better reliability, and random
disk access. A virtual tape drive does not require the usual maintenance tasks that
are associated with a physical tape drive, such as periodic cleaning and drive
calibration. Compared to the disk library, a virtual tape library offers easy
installation and administration because it is preconfigured by the manufacturer. A
key feature that is available on virtual tape library appliances is replication.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 601
Backup and Recovery Lesson
Information Storage and Management (ISM) v4
Page 602
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Backup Operation
VM
VM
Backup Clients
Hypervisor
3b
Backup
Device
4
3a
1
5
2
7
Backup Server
6
Storage Node
(1) Backup server initiates scheduled backup process.
(2) Backup server retrieves backup-related information from the backup catalog.
(3a) Backup server instructs storage node to load backup media in the backup
device.
(3b) Backup server instructs backup clients to send data to be backed up to the
storage node.
(4) Backup clients send data to storage node and update the backup catalog on the
backup server.
(5) Storage node sends data to the backup device
(6) Storage node sends metadata and media information to the backup server
(7) Backup server updates the backup catalog
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 603
Backup and Recovery Lesson
Notes
The backup operation is typically initiated by a server, but it can also be initiated by
a client. The backup server initiates the backup process for different clients that is
based on the backup schedule configured for them.
For example: the backup for a group of clients may be scheduled to start at 3:00
a.m. every day. The backup server coordinates the backup process with all the
components in a backup environment. The backup server maintains the information
about backup clients to be backed up and storage nodes to be used in a backup
operation. The backup server retrieves the backup related information from the
backup catalog. Based on this information, the backup server instructs the storage
node to load the appropriate backup media into the backup devices.
Simultaneously, it instructs the backup clients to gather the data to be backed up
and sends it over the network to the assigned storage node. After the backup data
is sent to the storage node, the client sends some backup metadata (the number of
files, name of the files, storage node details, and so on) to the backup server. The
storage node receives the client data, organizes it, and sends it to the backup
device. The storage node sends extra backup metadata (location of the data on the
backup device, time of backup, and so on) to the backup server. The backup server
updates the backup catalog with this information. The backup data from the client
can be sent to the backup device over a LAN or SAN network.
Hot backup and cold backup are the two methods that are deployed for backup.
They are based on the state of the application when the backup is performed. In a
hot backup, the application is up-and-running, with users accessing their data
during the backup process. This method of backup is also referred to as online
backup. The hot backup of online production data is challenging because data is
actively being used and changed. If a file is open, it is normally not backed up
during the backup process.
In such situations, an open file agent is required to back up the open file. These
agents interact directly with the operating system or application and enable the
creation of consistent copies of open files. The disadvantage that is associated with
a hot backup is that the agents usually affect the overall application performance. A
cold backup requires the application to be shut down during the backup process.
Hence, this method is also referred to as offline backup. Consistent backups of
Information Storage and Management (ISM) v4
Page 604
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
databases can also be done by using a cold backup. The disadvantage of a cold
backup is that the database is inaccessible to users during the backup process.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 605
Backup and Recovery Lesson
Recovery Operation
VM
VM
Hypervisor
Backup
Clients
4
1
Backup
Device
3
4
2
6
Backup Server
5
Storage Node
(1) Backup client requests backup server for data restore
(2) Backup server scans backup catalog to identify data to be restored and the
client that will receive data
(3) Backup server instructs storage node to load backup media in the backup
device
(4) Data is then read and sent to the backup client
(5) Storage node sends restore metadata to the backup server
(6) Backup server updates the backup catalog
Information Storage and Management (ISM) v4
Page 606
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Notes
After the data is backed up, it can be restored when required. A restore process
can be manually initiated from the client. A recovery operation restores data to its
original state at a specific PIT. Typically backup applications support restoring one
or more individual files, directories, or VMs. The illustration depicts a restore
operation.
Upon receiving a restore request, an administrator opens the restore application to
view the list of clients that have been backed up. While selecting the client for
which a restore request has been made, the administrator also needs to identify the
client that receives the restored data. Data can be restored on the same client for
whom the restore request has been made or on any other client.
The administrator then selects the data to be restored and the specified point in
time to which the data has to be restored based on the RPO. Because all this
information comes from the backup catalog, the restore application needs to
communicate with the backup server. The backup server instructs the appropriate
storage node to mount the specific backup media onto the backup device. Data is
then read and sent to the client that has been identified to receive the restored
data.Some restorations are successfully accomplished by recovering only the
requested production data. For example, the recovery process of a spreadsheet is
completed when the specific file is restored. In database restorations, additional
data, such as log files, must be restored along with the production data. This
approach ensures consistency of the restored data. In these cases, the RTO is
extended due to the additional steps in the restore operation. It is also important for
the backup and recovery applications to have security mechanisms to avoid
recovery of data by nonauthorized users.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 607
Backup and Recovery Lesson
Backup Granularity
Full backup
Incremental Backup
Cumulative (Differential) Backup
Amount of Data Backup
Different granularity levels are:

Full backup

Incremental backup

Cumulative backup
Notes
Backup granularity depends on business needs and the required RTO/RPO. Based
on the granularity, backups can be categorized as full, incremental, and cumulative
(or differential). Most organizations use a combination of these backup types to
meet their backup and recovery requirements.
Full Backup: It is a full copy of the entire data set. Organizations typically use full
backup on a periodic basis because it requires more storage space and also takes
more time to back up. The full backup provides a faster data recovery.
Information Storage and Management (ISM) v4
Page 608
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Incremental Backup: It copies the data that has changed since the last backup.
For example, a full backup is created on Monday, and incremental backups are
created for the rest of the week. Tuesday's backup would only contain the data that
has changed since Monday. Wednesday's backup would only contain the data that
has changed since Tuesday.The primary disadvantage to incremental backups is
that they can be time-consuming to restore. Suppose an administrator wants to
restore the backup from Wednesday. To do so, the administrator has to first restore
Monday's full backup. After that, the administrator has to restore Tuesday's copy,
followed by Wednesday's.
Cumulative Backup: It copies the data that has changed since the last full backup.
Suppose, for example, the administrator wants to create a full backup on Monday
and differential backups for the rest of the week. Tuesday's backup would contain
all of the data that has changed since Monday. It would therefore be identical to an
incremental backup at this point.On Wednesday, however, the differential backup
would backup any data that had changed since Monday (full backup). The
advantage that differential backups have over incremental is shorter restore times.
Restoring a differential backup never requires more than two copies.The tradeoff is
that as time progresses, a differential backup can grow to contain more data than
an incremental backup.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 609
Backup and Recovery Lesson
Agent-Based Backup
In this approach, an agent or client is installed on a virtual machine or a physical
compute system. The agent streams the backup data to the backup device as
shown in the illustration.

Agent is running inside the application servers (physical/virtual)
 Performs file-level backup

Impacts performance of applications running on compute systems
 Performing backup on multiple VMs on a compute system may consume
more resources and lead to resource contention
A
VM
VM
Hypervisor
Application Servers
A
Backup Server/ Storage Node
Backup Device
Agent
A
Notes
This backup does not capture virtual machine configuration files. The agent running
on the compute system consumes CPU cycles and memory resources. If multiple
VMs on a compute system are backed up simultaneously, then the combined I/O
and bandwidth demands that are placed on the compute system by the various
backup operations can deplete the compute system resources.
This approach may impact the performance of the services or applications running
on the VMs. To overcome these challenges, the backup process can be offloaded
from the VMs to a proxy server. This can be achieved by using the image-based
backup approach.
Information Storage and Management (ISM) v4
Page 610
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 611
Backup and Recovery Lesson
Image-Based Backup
Image-based backup makes a copy of the virtual drive and configuration that are
associated with a particular VM.

Backup is saved as a single entity called a VM image
 Enables quick restoration of a VM

Supports recovery at VM-level and file-level

No agent is required inside the VM to perform backup

Backup processing is offloaded from VMs to a proxy server
VM Snapshot
FS Volume
VM
VM
VM
Proxy Server
VM
Create Snapshot
Mount the
Snapshot
Hypervisor
Hypervisor
Backup
Notes
Image-based backup makes a copy of the virtual drive and configuration that are
associated with a particular VM. The backup is saved as a single entity called as
VM image. This type of backup is suitable for restoring an entire VM if there is a
hardware failure or human error such as the accidental deletion of the VM. The
image - based backup also supports file-level recovery.
In an image-level backup, the backup software can backup VMs without installing
backup agents inside the VMs or at the hypervisor-level. The backup processing is
performed by a proxy server that acts as the backup client, thereby offloading the
backup processing from the VMs. The proxy server communicates to the
management server responsible for managing the virtualized compute
environment. It sends commands to create a snapshot of the VM to be backed up
and to mount the snapshot to the proxy server. A snapshot captures the
configuration and virtual drive data of the target VM and provides a point-in-time
view of the VM. The proxy server then performs backup by using the
Information Storage and Management (ISM) v4
Page 612
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
snapshot.Some vendors support incremental backup through tracking changed
blocks. This feature identifies and tags any blocks that have changed since the last
VM snapshot. This approach enables the backup application to backup only the
blocks that have changed, rather than backing up every block. This considerably
reduces the amount of data to be backed up and the number of VM that needs to
be backed up within a backup window.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 613
Backup and Recovery Lesson
Image-Based Backup: Recovery-In-Place
Definition: Recovery-in-place
A term that refers to running a VM directly from the backup device,
using a backed up copy of the VM image instead of restoring that
image file.

Eliminates the need to transfer the image from the backup device to the primary
storage before it is restarted
 Provides an almost instant recovery of a failed VM

Requires a random access device to work efficiently
 Disk-based backup target

Reduces the RTO and network bandwidth to restore VM files
Notes
One of the primary benefits of recovery in place is that it eliminates the need to
transfer the image from the backup area to the primary storage area before it is
restarted. So, the application that is running on those VMs can be accessed more
quickly. This method not only saves time for recovery, but also reduces network
bandwidth to restore files.
Information Storage and Management (ISM) v4
Page 614
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
NDMP-Based Backup
Definition: NDMP
An open standard TCP/IP-based protocol that is designed for a
backup in a NAS environment.

Data can be backed up using NDMP regardless of the operating system or
platform

Backup data is sent directly from NAS to the backup device
 No longer necessary to transport data through application servers

Backs up and restores data while preserving security attributes of file system
(NFS and CIFS) and maintains data integrity
Notes
As the amount of unstructured data continues to grow exponentially, organizations
face the daunting task of ensuring that critical data on NAS systems are protected.
Most NAS heads run on proprietary operating systems that are designed for
serving files.
To maintain its operational efficiency generally, it does not support the hosting of
third-party applications such as backup clients. This forced backup administrators
to backup data from application server or mount each NAS volume through CIFS or
NFS from another server across the network, which hosted a backup agent. These
approaches may lead to performance degradation of application server and
production network during backup operations, due to overhead.
Further, security structures differ on the two network file systems, NFS and CIFS.
Backups that are implemented through one of the file systems would not effectively
backup any data security attributes on the NAS head that was accessed through a
different file system. For example, CIFS backup, when restored, would not be able
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 615
Backup and Recovery Lesson
to restore NFS file attributes and vice versa. These backup challenges of the NAS
environment can be addressed with the use of Network Data Management Protocol
(NDMP).
NDMP is an industry-standard TCP/IP-based protocol that is designed for a backup
in a NAS environment. It communicates with several elements in the backup
environment (NAS head, backup devices, backup server, and so on) for data
transfer and enables vendors to use a common protocol for the backup
architecture. Data can be backed up using NDMP regardless of the operating
system or platform. NDMP backs up and restores data without losing the data
integrity and file system structure (regarding different rights and permission in
different file systems).
Due to its flexibility, it is no longer necessary to transport data through the
application server, which reduces the load on the application server and improves
the backup speed. NDMP optimizes backup and restore by using the high-speed
connection between the backup devices and the NAS head. In NDMP, backup data
is sent directly from the NAS head to the backup device, whereas metadata is sent
to the backup server.
Information Storage and Management (ISM) v4
Page 616
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Primary Storage-Based Backup
VM
VM
A
Backup Data
Hypervisor
Application
Servers
Storage
Network
Storage
Network
Primary Storage System
A
Backup
Device
Agent
This backup approach backs up data directly from primary storage system to
backup target without requiring additional backup software.
This backup approach backs up data directly from primary storage system to
backup target without requiring additional backup software.

Eliminates the backup impact on application servers

Improves the backup and recovery performance to meet SLAs
Notes
Typically, an agent runs on the application servers that control the backup process.
This agent stores configuration data for mapping the LUNs on the primary storage
system to the backup device to orchestrate backup (the transfer of changed blocks
and creation of backup images) and recovery operations. This backup information
(metadata) is stored in a catalog which is local to the application server.
When a backup is triggered through the agent running on application server, the
application momentarily pauses simply to mark the point in time for that backup.
The data blocks that have changed since the last backup is sent across the
network to the backup device. The direct movement from primary storage to
backup device eliminates the LAN impact by isolating all backup traffic to the SAN.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 617
Backup and Recovery Lesson
This approach eliminates backup impact on application servers and provides faster
backup and recovery to meet the application protection SLAs.
For data recovery, the backup administrator triggers recovery operation and then
the primary storage reads the backup image from the backup device. The primary
storage replaces production LUN with the recovered copy.
Information Storage and Management (ISM) v4
Page 618
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
Cloud-Based Backup: Backup as a Service
Cloud
Backup Data to Cloud
VM
Restore Data from Cloud
VM
Backup
Clients

Enables consumers to procure backup services on demand through a selfservice portal
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 619
Backup and Recovery Lesson
 Provides the capability to perform backup and recovery at any time, from
anywhere

Reduces the backup management overhead
 Transforms from CAPEX to OPEX
 Pay-per-use/subscription-based pricing
 Enables organizations to meet long-term retention requirements

Backing up to cloud ensures regular and automated backup of data

Gives consumers the flexibility to select a backup technology based on their
current requirements
Notes
Data is important for businesses of all sizes. Organizations need to regularly back
up data to avoid losses, stay compliant, and preserve data integrity. IT
organizations today are dealing with the explosion of data, particularly with the
development of third platform technologies. Data explosion poses the challenge of
data backup and quick data restore. It strains the backup windows, IT budget, and
IT management. The growth and complexity of the data environment, added with
proliferation of virtual machines and mobile devices constantly outpaces the
existing data backup plans.
Deployment of a new backup solution takes weeks of planning, justification,
procurement, and setup. However, technology and data protection requirements
change quickly. Enterprises must also comply with regulatory and litigation
requirements. These challenges can be addressed with the emergence of cloudbased backup (backup as a service).
Backup as a service enables organizations to procure backup services on-demand
in the cloud. The backup service is offered by a service provider to consumers.
Organizations can build their own cloud infrastructure and provide backup services
on demand to their employees/users. Some organizations prefer a hybrid cloud
option for their backup strategy. They keep a local backup copy in their private
cloud and use a public cloud for keeping their remote copy for DR purpose. For
Information Storage and Management (ISM) v4
Page 620
© Copyright 2019 Dell Inc.
Backup and Recovery Lesson
providing backup as a service, organizations and service providers should have
necessary backup technologies in place to meet the required service levels.
Backup as a service enables individual consumers or organizations to reduce their
backup management overhead. It also enables the individual consumer/user to
perform backup and recovery anytime, from anywhere, using a network connection.
Consumers do not need to invest in capital equipment to implement and manage
their backup infrastructure. These infrastructure resources are rented without
obtaining ownership of the resources. Based on the consumer demand, backups
can be scheduled and infrastructure resources can be allocated with a metering
service. This will help to monitor and report resource consumption.
Many organizations’ remote and branch offices have limited or no backup in place.
Mobile workers represent a particular risk because of the increased possibility of
lost or stolen devices. Backing up to cloud ensures regular and automated backup
of data. Cloud computing gives consumers the flexibility to select a backup
technology, based on their requirement. It also enables to quickly move to a
different technology when their backup requirement changes.
Data can be restored from the cloud using two methods, namely web-based restore
and media-based restore. In web-based restore, the requested data is gathered
and sent to the server, running cloud backup agent. The agent software restores
data on the server. This method is considered if sufficient bandwidth is available. If
a large amount of data needs to be restored and sufficient bandwidth is not
available, then the consumer may request data restoration using backup media
such as DVD or disk drives. In this option, the service provider gathers the data to
restore, stores data to a set of backup media, and ships it to the consumer.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 621
Data Deduplication Lesson
Data Deduplication Lesson
Introduction
This lesson presents the need for data deduplication, and the factors affecting
deduplication ratio. This lesson also focuses on source-based and target-based
deduplication.
This lesson covers the following topics:

Drivers for data deduplicationü

Factors affecting deduplication ratio

Source-based and target-based deduplication
Information Storage and Management (ISM) v4
Page 622
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
Data Deduplication
Video: Data Deduplication
The video is located at
https://edutube.emc.com/Player.aspx?vno=gHpJBZz2XqTo2FGvK/UM7w
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 623
Data Deduplication Lesson
What is Data Deduplication?
Definition: Data Deduplication
The process of detecting and identifying the unique data segments
within a given set of data to eliminate redundancy.

Duplication process:
 Chunk the dataset
 Identify duplicate chunk
Deduplication
 Eliminate the redundant
chunk

Deduplication could be
performed in backup and
production environment

Effectiveness of
deduplication is expressed
as a deduplication ratio
After deduplication unique
segments = 3
Before deduplication total
segments = 39
Notes
The use of deduplication techniques reduces the amount of data to be backed-up.
Data deduplication operates by segmenting a dataset into blocks and identifying
redundant data and writing the unique blocks to a backup target.
To identify redundant blocks, the data deduplication system creates a hash value
or digital signature, like a fingerprint, for each data block. It also creates an index of
the signatures for a given repository. The index provides the reference list to
determine whether blocks exist in a repository.
When the data deduplication system sees a block it has processed before, instead
of storing the block again, it inserts a pointer to the original block in the repository.
It is important to note that the data deduplication can be performed in backup as
well as in production environment. In production environment, the deduplication is
Information Storage and Management (ISM) v4
Page 624
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
implemented at primary storage systems to eliminate redundant data in the
production volume.The effectiveness of data deduplication is expressed as a
deduplication ratio. It is the ratio of data before deduplication to the amount of data
after deduplication. This ratio is typically depicted as “ratio:1” or “ratio X” (10:1 or 10
X). For example, if 200 GB of data consumes 20 GB of storage capacity after data
deduplication, the space reduction ratio is 10:1.
Every data deduplication vendor claims that their product offers a certain ratio of
data reduction. However, the actual data deduplication ratio varies, based on many
factors.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 625
Data Deduplication Lesson
Drivers for Data Deduplication
Capacity requirements are growing
year over year – Increases storage
cost
Shorter backup windows due to the
need for 24x7 service availability
Limited
Budget
Limited
Backup
Window
Network
Bandwidth
Constrain
Longer
Retention
Period
Data is distributed across remote
locations (cloud) for DR purpose –
Requires huge network bandwidth
Regulatory requirement demand to
keep data for longer periods
Notes
With the growth of data and 24x7 service availability requirements, organizations
are facing challenges in protecting their data. Typically, many redundant data is
backed-up. It increases the backup window size and also results in unnecessary
consumption of resources, such as backup storage space and network bandwidth.
There are also requirements to preserve data for longer periods – whether driven
by the need of consumers or legal and regulatory concerns. Backing up large
amount of duplicate data at the remote site or cloud for DR purpose is also
cumbersome and requires lots of bandwidth.
Data deduplication provides the solution for organizations to overcome these
challenges in a backup environment.
Information Storage and Management (ISM) v4
Page 626
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
Factors Affecting Deduplication Ratio
Factor
Description
Retention period
Longer the data retention period, the greater is the chance of
identical data existence in the backup
Frequency of full
backup
More frequently the full backups are conducted, the greater is
the advantage of deduplication
Change rate
Fewer the changes to the content between backups, the
greater is the efficiency of deduplication
Data type
The more unique the data, the less intrinsic duplication exists
Deduplication
method
The highest amount of deduplication across an organization is
discovered using variable-length, sub-file deduplication
Notes
Data deduplication performance (or ratio) is tied to the following factors:
Retention period: This is the period of time that defines how long the backup
copies are retained. The longer the retention, the greater is the chance of identical
data existence in the backup set which would increase the deduplication ratio and
storage space savings.
Frequency of full backup: As more full backups are performed, it increases the
amount of same data being repeatedly backed-up. So, it results in high
deduplication ratio.
Change rate: This is the rate at which the data received from the backup
application changes from backup to backup. Client data with a few changes
between backups produces higher deduplication ratios.
Data type: Backups of user data such as text documents, PowerPoint
presentations, spreadsheets, and emails are known to contain redundant data and
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 627
Data Deduplication Lesson
are good deduplication candidates. Other data such as audio, video, and scanned
images are highly unique and typically do not yield good deduplication ratio.
Deduplication method: Deduplication method also determines the effective
deduplication ratio. Variable-length, subfile deduplication discovers the highest
amount of deduplication of data.
Information Storage and Management (ISM) v4
Page 628
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
Deduplication Granularity Level
The level at which data is identified as duplicate affects the amount of redundancy
or commonality. The operational levels of deduplication include file-level
deduplication and sub-file deduplication.
File-level Deduplication

Detects and removes redundant copies of identical files

Only one copy of the file is stored; the subsequent copies are replaced with a
pointer to the original file

Does not address the problem of duplicate content inside the files
Sub-file Level Deduplication
Breaks down files to smaller segments

Detects redundant data within and across files
Two methods:

Fixed-length block

Variable-length block
Notes
File-level deduplication (also called single instance storage) detects and removes
redundant copies of identical files in a backup environment. Only one copy of the
file is stored; the subsequent copies are replaced with a pointer to the original file.
By removing all of the subsequent copies of a file, a significant amount of space
savings can be achieved. File-level deduplication is simple but does not address
the problem of duplicate content inside the files. A change in any part of a file also
results in classifying that as a new file and saving it as a separate copy. For
example, two 10-MB presentations with a difference in just the title page are not
considered as duplicate files, and each file is stored separately.
Sub-file deduplication breaks the file into smaller blocks and then uses a standard
hash algorithm to detect redundant data within and across the file. As a result, subfile deduplication eliminates duplicate data across files. There are two forms of sub-
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 629
Data Deduplication Lesson
file deduplication, fixed-length and variable-length. The fixed-length block
deduplication divides the files into fixed-length blocks and uses a hash algorithm to
find duplicate data. Although simple in design, the fixed-length block may miss
opportunities to discover redundant data because the block boundaries of similar
data may be different. For example: the addition of a person’s name to a
document’s title page may shift the whole document, and make all blocks appear to
have changed, causing the failure of the deduplication method to detect
equivalencies. In variable-length block deduplication, if there is a change in the
block and then the boundary for that block only is adjusted, leaving the remaining
blocks unchanged. More data is identified as common data, and there is less
backup data to store as only the unique data is backed-up. Variable-length block
deduplication yields a greater granularity in identifying duplicate data, improving
upon the limitations of file-level, and fixed-length block level deduplication.
Information Storage and Management (ISM) v4
Page 630
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
Source-Based Deduplication Method

Data is deduplicated at the
source (backup client)
 Backup client sends only
new, unique segments
across the network



Deduplication at Source
VM
VM
Hypervisor
Reduced storage capacity
and network bandwidth
requirements
Application Server (Backup
Client)
Recommended for ROBO
environment for taking
centralized backup
Deduplication Server
Backup
Device
Deduplication Agent
Cloud service providers use
this method when performing
backup from consumer’s location to their location
Notes
Source-based data deduplication eliminates redundant data at the source (backup
client) before transmission to the backup device. The deduplication software or
agent on the clients checks each file or block for duplicate content. Source-based
deduplication reduces the amount of data that is transmitted over a network from
the source to the backup device, thus requiring less network bandwidth. There is
also a substantial reduction in the capacity that is required to store the backup
data.
However, a deduplication agent running on the client may impact the backup
performance, especially when a large amount of data needs to be backed-up.
When image-level backup is implemented, the backup workload is moved to a
proxy server. The deduplication agent is installed on the proxy server to perform
deduplication without impacting the VMs running applications. Organizations can
implement source-based deduplication when performing backup (backup as a
service) from their location to provider’s location.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 631
Data Deduplication Lesson
Target-Based Deduplication Method

Data is deduplicated at the
target
Deduplication at
Target
 Inline
 Post-process



VM
Offloads the backup client
from deduplication process
Requires sufficient network
bandwidth
VM
Hypervisor
Application Server (Backup
Client)
In some implementations,
part of the deduplication load
is moved to the backup
server
Deduplication
Server
Backup
Device
Deduplication Appliance
 Reduces the burden on the target
 Improves the overall backup performance
Notes
Target-based data deduplication occurs at the backup device, which offloads the
deduplication process and its performance impact from the backup client. In targetbased deduplication, the backup application sends data to the target backup device
where the data is deduplicated, either immediately (inline) or at a scheduled time
(post-process).
With inline data deduplication, the incoming backup stream is divided into small
chunks, and then compared to data that has already been deduplicated. The inline
deduplication method requires less storage space than the post process approach.
However, inline deduplication may slow down the overall data backup process.
Inline deduplication systems of some vendors use the continued advancement of
CPU technology. This increases the performance of the inline deduplication by
minimizing disk accesses required to deduplicate data. Such inline deduplication
systems identify duplicate data segments in memory, which minimizes the disk
usage.
Information Storage and Management (ISM) v4
Page 632
© Copyright 2019 Dell Inc.
Data Deduplication Lesson
In post-process deduplication, the backup data is first stored to the disk in its native
backup format and deduplicated after the backup is complete. In this approach, the
deduplication process is separated from the backup process and the deduplication
happens outside the backup window. However, the full backup dataset is
transmitted across the network to the storage target before the redundancies are
eliminated. So, this approach requires adequate storage capacity to accommodate
the full backup dataset.
Organizations can consider implementing target-based deduplication when their
backup application does not have built in deduplication capabilities. It supports the
current backup environment without any operational changes. Target-based
deduplication reduces the amount of storage that is are required, but unlike sourcebased deduplication, it does not reduce the amount of data that is are sent across a
network during the backup. In some implementations, part of the deduplication
functionality is moved to the backup client or backup server. This reduces the
burden on the target backup device for performing deduplication and improves the
overall backup performance.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 633
Data Archiving Lesson
Data Archiving Lesson
Introduction
This lesson presents data archiving operations and difference between backup and
archiving. This lesson also focuses on purpose-built archive storage and cloudbased archiving.
This lesson covers the following topics:

Data archiving operations

Backup vs. Archiving

Purpose-built archive storage

üCloud-based archiving
Information Storage and Management (ISM) v4
Page 634
© Copyright 2019 Dell Inc.
Data Archiving Lesson
ISMv4 Source - Data Protection Solutions - Data Archiving
Video: Data Archiving
The video is located at
https://edutube.emc.com/Player.aspx?vno=3vxUpJGQRpkqYPvf4+D5ew
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 635
Data Archiving Lesson
Data Archiving Overview
Definition: Data Archiving
The process of identifying and moving inactive data out of current
production systems into low-cost storage tier for long-term retention
and future reference.

Data archive is a repository where fixed content is stored

Organizations set their own policies for qualifying data to archive.

Archiving enables organizations to:
 Reduce on-going primary storage acquisition costs
 Meet regulatory compliance
 Reduce backup challenges including the backup window by moving static
data out of the recurring backup stream process
 Use this data for generating new revenue strategies
Information Storage and Management (ISM) v4
Page 636
© Copyright 2019 Dell Inc.
Data Archiving Lesson
Notes
In the information life cycle, data , accessed, and changed. As data ages, it is less
likely to be changed and eventually becomes “fixed” but remains accessed by
applications and users. This data is called fixed content. Assets such as X-rays,
MRIs, CAD/CAM designs, surveillance video, MP3s, and financial documents are
examples of fixed data. These data are growing at over 90% annually.
Data archiving is the process of moving data (fixed content) that is no longer
actively accessed to a separate low-cost archival storage tier for long-term
retention and future reference. Data archive is a storage repository that is used to
store these data. Organizations set their own policies for qualifying data to move
into archives. These policy settings are used to automate the process of identifying
and moving the appropriate data into the archive system. Organizations implement
archiving processes and technologies to reduce primary storage cost. With
archiving, the capacity on expensive primary storage can be reclaimed by moving
infrequently accessed data to lower-cost archive tier. Archiving fixed content before
taking backup helps to reduce the backup window and backup storage acquisition
costs.
Government regulations and legal/contractual obligations mandate organizations to
retain their data for an extended period. The key to determine how long to retain
archives of an organization is to understand which regulations apply to the
particular industry and which retention rules apply to that regulation.
For instance, all publicly traded companies are subject to the Sarbanes-Oxley
(SOX) Act. This act defines email retention requirements, among other things
related to data storage and security.
Archiving helps organizations to adhere to compliances. Archiving can help
organizations use growing volumes of information in potentially new and
unanticipated ways.
For example, new product innovation can be fostered if engineers can access
archived project materials such as designs, test results, and requirement
documents. Besides to meeting governance and compliance requirements,
organizations retain data for business intelligence and competitive advantage. Both
active and archived information can help data scientists drive innovations or help to
improve current business processes.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 637
Data Archiving Lesson
Backup Vs. Archiving
Data archiving is often confused with data backup. Backups are used to restore
data in case it is lost, corrupted, or destroyed. In contrast, data archives protect
older data that is not required for everyday business operations but may
occasionally need to be accessed.
The table compares some of the significant differences between backup and
archiving.
Data Backup
Data Archiving
Secondary copy of data
Primary copy of data
Used for data recovery operations
Available for data retrieval
Primary objective – operational recovery Primary objective – compliance
and disaster recovery
adherence and lower cost
Typically short-term (weeks or months)
retention
Long-term (months, years, or decades)
retention
Information Storage and Management (ISM) v4
Page 638
© Copyright 2019 Dell Inc.
Data Archiving Lesson
Data Archiving Operations

Archiving agent scans primary storage to find files that meet the archiving
policy. The archive server indexes the files.

Once the files have been indexed, they are moved to archive storage and small
stub files are left on the primary storage.
Primary Storage
Communication
Index
Network
Archive Server
Clients
Archive Storage
Notes
The data archiving operation has an archiving agent, archive server/policy engine,
and archive storage. The archiving agent scans the primary storage to find files that
meet the archiving policy. This policy is defined on the archive server (policy
engine).
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 639
Data Archiving Lesson
After the files are identified for archiving, the archive server creates the index for
the files. Once the files have been indexed, they are moved to the archive storage
and small stub files are left on the primary storage. In other words, each archived
file on primary storage is replaced with a stub file. The stub file contains the
address of the archived file. As the size of the stub file is small, it saves space on
primary storage.
From the perspective of a client, the data movement from primary storage to
secondary storage is transparent.
Information Storage and Management (ISM) v4
Page 640
© Copyright 2019 Dell Inc.
Data Archiving Lesson
Use Case: Email Archiving

Emails are a part of business processes.
 They represent a correspondence between
two or more parties and are immutable
after generation.

Email archiving is the process of archiving
emails from the mail server to an archive
storage.
 After the email is archived, it is retained for
years, based on the retention policy.
Legal Dispute
Email archiving helps an organization to address legal disputes.
For example, an organization may be involved in a legal dispute. They need to
produce all emails within a specified time period containing specific keywords that
were sent to or from certain people.
Government Compliance
Email archiving helps to meet government compliance requirements such as
Sarbanes-Oxley and SEC regulations.
For example, an organization may need to produce all emails from all individuals
that are involved in stock sales or transfers. Failure to comply with these
requirements could cause an organization to incur penalties.
Mailbox Space Savings
Email archiving provides more mailbox space by moving old emails to archive
storage.
For example, an organization may configure a quota on each mailbox to limit its
size. A fixed quota for a mailbox forces users to delete emails as they approach the
quota size. However, users often need to access emails that are weeks, months, or
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 641
Data Archiving Lesson
even years old. With email archiving, organizations can free up space in user
mailboxes and still provide user access to older emails.
Information Storage and Management (ISM) v4
Page 642
© Copyright 2019 Dell Inc.
Data Archiving Lesson
Purpose-Built Archive Storage – CAS
Content addressed storage (CAS) is an object-based storage device that is
purposely built for storing and managing fixed data.

Each object that is stored in CAS is assigned a globally unique content address
(digital fingerprint of the content).

Application server accesses the CAS device through the CAS API.
Network
Client
Application
Server
CAS
CAS API
Notes
CAS stores user data and its attributes as an object. The stored object is assigned
a globally unique address, which is known as a content address (CA). This address
is derived from the binary representation of an object. Content addressing
eliminates the need for application servers to understand and manage the physical
location of objects on a storage system.
Content address (digital fingerprint of the content) not only simplifies the task of
managing huge number of objects, but also ensures content authenticity. The
application server can access the CAS device only through the CAS API.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 643
Data Archiving Lesson
Information Storage and Management (ISM) v4
Page 644
© Copyright 2019 Dell Inc.
Data Archiving Lesson
Cloud-Based Archiving
Organizations prefer hybrid cloud options. Archived data that may require highspeed access is retained internally (private cloud) while lower-priority archive data
is moved to low-cost, public cloud-based archive storage.

No CAPEX, pay-as-you-go, faster deployment

Reduced management overhead of IT

Supports massive data growth and retention requirements
Primary Storage
VM
VM
Archive
Data
Hypervisor
WAN
Network
Cloud
Email/File Server
Archiving Server
(Policy Engine)
Data Center
Notes
In a traditional in-house data archiving model, archiving systems and underlying
infrastructure are deployed and managed within an organization’s data center. Due
to exponential data growth, organizations are facing challenges with increased cost
and complexity in their archiving environment. Often an existing infrastructure is
siloed by architecture and policy. Organizations are looking for new ways to
improve the agility and the scalability of their archiving environments.
Cloud computing provides highly scalable and flexible computing that is available
on demand. It empowers self-service requesting through a fully automated requestfulfillment process in the background. It provides capital cost savings and agility to
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 645
Data Archiving Lesson
organizations. With cloud-based archiving, organizations are required to pay as
they use and can scale the usage as needed. It also enables the organization to
access their data from any device and any location.
Typically a cloud-based archiving service is designed to classify, index, search, and
retrieve data in a security-rich manner. It automates regulatory monitoring and
reporting. It also enables organizations to consistently enforce the policies for the
centralized cloud archive repository. Hybrid cloud archiving is one step toward the
cloud from the traditional in-house approach. Archived data that may require highspeed access is retained internally. while lower-priority archive data is moved to
low-cost, public cloud-based archive storage.
Information Storage and Management (ISM) v4
Page 646
© Copyright 2019 Dell Inc.
Migration Lesson
Migration Lesson
Introduction
This lesson presents importance of data migrations and various types of data
migration. This lesson also focuses on Disaster Recovery as a Service (DRaaS).
This lesson covers the following topics:

Types of data migrations

Disaster Recovery as a Service (DRaaS)
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 647
Migration Lesson
Migration
Video: Data Migration
The video is located at
https://edutube.emc.com/Player.aspx?vno=nb2RfSXSY/hFxiyjyc7vUg
Information Storage and Management (ISM) v4
Page 648
© Copyright 2019 Dell Inc.
Migration Lesson
Data Migration
Definition: Data Migration
Involves the transfer of data between hosts (physical or virtual),
storage devices, or formats.

In today’s competitive business environment, IT organizations should require
non-disruptive live migration solutions in place to meet the required SLAs

Organization deploys data migration solutions for the following reasons:
 Data center maintenance without downtime
 Disaster avoidance
 Technology refresh
 Data center migration or consolidation
 Workload balancing across data centers (multiple sites)
Notes
Traditionally, migrating data and applications within or between data centers
involved a series of manual tasks and activities. IT would either make physical
backups or use data replication services to transfer applications and data to an
alternate location. Applications had to be stopped and could not be restarted until
testing and verification were complete. In today’s competitive business
environment, IT organizations should require non-disruptive live migration solutions
in place to meet the required SLAs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 649
Migration Lesson
Storage System-Based Migration

Moves data between heterogeneous storage systems
 Storage system that performs migration is called as control storage system

Push: Data is pushed from control system to remote system

Pull: Data is pulled to the control system from remote system
Push
Control
Device
Remote
Device
SAN
Pull
Control Storage
System
Remote Storage
System
Notes
Storage system-based migration moves data between heterogeneous storage
systems. This technology is application and server-operating-system independent
because the migration operations are performed by one of the storage systems.
The storage system that performs migration operations is called as control storage
system. Data can be moved from/to the devices in the control storage system
to/from a remote storage system.
Data migration solutions perform push and pull operations for data movement.
These terms are defined from the perspective of the control storage system. In the
push operation, data is moved from the control storage system to the remote
storage system. In the pull operation, data is moved from the remote storage
system to the control storage system.
Information Storage and Management (ISM) v4
Page 650
© Copyright 2019 Dell Inc.
Migration Lesson
During the push and pull operations, compute system’s access to the remote
device is not enabled. Since, the control storage system has no control over the
remote storage and cannot track any change on the remote device. Data integrity
cannot be guaranteed if changes are made to the remote device during the push
and pull operations. The push/pull operations can be either hot or cold. These
terms apply to the control devices only.
In a cold operation, the control device is inaccessible to the compute system during
migration. Cold operations guarantee data consistency because both the control
and the remote devices are offline. In a hot operation, the control device is online
for compute system operations. During hot push/pull operations, changes can be
made to the control device. Since, the control storage system can keep track of all
changes, and thus ensure data integrity.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 651
Migration Lesson
Virtualization Appliance-Based Migration

Virtualization layer handles the migration of data
 Enables LUNs to remain online and accessible by compute system while
data is migrating

Support data migration between multivendor heterogeneous storage systems

Service provider could implement to migrate the customer data from their
storage system to a cloud-based storage

Example:
 An administrator wants to perform a data migration from storage system A to
system B as shown in the illustration
 The virtualization layer handles the migration of data, which enables LUNs
to remain online and accessible while data is migrating
 In this case, physical changes are not required because the compute system
still points to the same virtual volume on the virtualization layer
 However, the mapping information resides on the appliance should be
changed. These changes can be run dynamically and made transparent to
the user
Information Storage and Management (ISM) v4
Page 652
© Copyright 2019 Dell Inc.
Migration Lesson
VM
VM
Notes
Hypervisor
Data migration can also
be implemented using a
virtualization appliance
at the SAN. Virtualization
Virtual Volume
appliance provides a
translation layer in the
SAN, between the
FC SAN
compute systems and
Storage
System A
Data Migration
the storage systems.
The LUNs created at the
storage systems are
assigned to the
appliance. The appliance
abstracts the identity of
these LUNs and creates
a storage pool by aggregating LUNs from the storage systems.
LUN
Compute
System
Virtualization
Appliance
Storage
System B
LUN
A virtual volume is created from the storage pool and assigned to the compute
system. When an I/O is sent to a virtual volume, it is redirected through the
virtualization layer to the mapped LUNs. The key advantage of using virtualization
appliance is to support data migration between multivendor heterogeneous storage
systems.
In a cloud environment, the service provider could also implement virtualizationbased data migration. They migrate the customer data from their storage system to
a shared storage used by the service provider. This approach enables the
customer to migrate without causing downtime to their applications and users
during the migration process. The providers themselves perform this data migration
without the need to go for a third-party data migration specialist.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 653
Migration Lesson
Hypervisor-Based Migration: VM Migration
Running services on VMs are moved from one physical compute system to another
without any downtime:

Enables scheduled maintenance without any downtime

Facilitates VM load balancing
Services
Migrated VMs
VM
VM
VM
VM
VM Migration
Services
Network
Compute System 1
Compute System 2
Hypervisor
Hypervisor
VM Live Migration with Hypervisor Cluster
Storage
System
Notes
Organizations using a virtualized infrastructure have many reasons to move
running VMs from one physical compute system to another. The compute systems
can be located within a data center or across data centers. The migration can be
used for routine maintenance, and VM distribution across sites to balance system
load.
The migration can also be used for disaster recovery, or consolidating VMs onto
fewer physical compute systems. The ideal virtual infrastructure platform should
enable organizations to move the running VMs as quickly as possible and with
minimal impact on the users. This can be achieved with the help of implementing
VM live migrations.
Information Storage and Management (ISM) v4
Page 654
© Copyright 2019 Dell Inc.
Migration Lesson
In a VM live migration the entire active state of a VM is moved from one hypervisor
to another. The state information includes memory contents and all other
information that identifies the VM. This method involves copying the contents of VM
memory from the source hypervisor to the target. Then transferring the control of
the VM’s disk files to the target hypervisor. Next, the VM is suspended on the
source hypervisor, and the VM is resumed on the target hypervisor.
Performing VM live migration requires a high-speed network connection. It is
important to ensure that even after the migration, the VM network identity and
network connections are preserved. VM live Migration with stretched cluster
provides the ability to move VMs across data centers. This solution is suitable for
cloud environment, where consumers of a given application are spread across the
globe and working in different time zones. If an application is closer to the
consumers, then the productivity is enhanced to a great extent.
Live migration with stretched cluster provides the ability to move VMs and
applications to a location that is closest to the consumer for faster/reliable access.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 655
Migration Lesson
Hypervisor-Based Migration: VM Storage Migration

Migrates VM files from one storage system to another without any service
disruption
– Simplify array migration and storage upgrades
– Dynamically optimize storage I/O performance
– Efficiently manage storage capacity
VM
VM
Notes
Hypervisor
Compute
System
In a VM storage migration, VM
files are moved from one storage
system to another system without
Network
any downtime. This approach
enables the administrator to
VM
move VM files across dissimilar
VM
storage systems. VM storage
VM
migration starts by copying the
metadata about the VM from the
VM
Storage Systems
source system to the target
storage system. The metadata
essentially consists of
configuration, swap, and log files.
After the metadata is copied, the VM disk file is moved to the new location. During
migration, there might be a chance that the source is updated. It is necessary to
track the changes on the source to maintain data integrity. After the migration is
completed, the blocks that have changed since the migration has started are
transferred to the new location.
Information Storage and Management (ISM) v4
Page 656
© Copyright 2019 Dell Inc.
Migration Lesson
The key benefits of VM storage migration are:

Simplify array migration and storage upgrades: The traditional process of
moving data to new storage is cumbersome, time-consuming, and disruptive.
With VM storage migration, organization can make it easier and faster to
embrace new storage platforms. This is to adopt flexible leasing models, retire
older systems, and conduct storage upgrades.

Dynamically optimize storage I/O performance: With storage migration, IT
administrators can move VM disk files to alternative LUNs that are properly
configured to deliver optimal performance. This migration avoids scheduled
downtime, eliminating the time and cost associated with traditional methods.

Efficiently manage storage capacity: Nondisruptive VM disk file migration to
different classes of storage enables cost-effective management of VM disks as
part of a tiered storage strategy.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 657
Migration Lesson
Disaster Recovery as a Service (DRaaS)

Enables organizations to have a DR site in the cloud
 Service provider offers resources to run consumer’s IT services in the cloud
during disaster
 Pay-as-you-go pricing model

Resources at the service provider location may be dedicated to the consumer,
or they can be shared

During normal production operations, IT services run at the consumer’s
production data center

If there is a disaster, the business operations failover to the provider’s
infrastructure
Notes
Organizations need to rely on business continuity processes to mitigate the impact
of service disruptions due to disaster. Traditional disaster recovery methods often
require buying and maintaining a complete set of IT resources at secondary data
centers. This IT resources should match the business-critical systems at the
primary data center. This includes sufficient storage to house a complete copy of all
business data at the secondary site. This may be a complex process and
expensive solution for organizations.
Disaster Recovery-as-a-Service (DRaaS) has emerged as a solution that offers a
viable DR solution to organizations. DRaaS enables organizations to have a DR
site in the cloud. The cloud service provider assumes the responsibility for
providing IT resources to enable organizations to continue running their IT services
if there is a disaster. Resources at the service provider’s location may either be
dedicated to the consumer or they can be shared.
From organizations (consumers) perspective, having a DR site in the cloud reduces
the need for data center space and IT infrastructure. This approach leads to
significant cost reductions, and eliminates the need for upfront capital expenditure.
DRaaS is gaining popularity among organizations. This is due to its pay-as-you-go
Information Storage and Management (ISM) v4
Page 658
© Copyright 2019 Dell Inc.
Migration Lesson
pricing model and the use of automated virtual platforms. This can lower costs and
minimize the recovery time after a failure. During normal production operations, IT
services run at the organization’s production data center. Replication of data occurs
from the organization’s production environment to the cloud over the network.
Typically during normal operating conditions, a DRaaS implementation may only
need a small share of resources. This helps to synchronize the application data
and VM configurations from the consumer’s site to the cloud. The full set of
resources required to run the application in the cloud is consumed only if a disaster
occurs. If there is a business disruption or disaster, the business operations failover
to the provider’s infrastructure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 659
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

Dell EMC NetWorker

Dell EMC Avamar

Dell EMC Data Domain

Dell EMC Integrated Data Protection Appliance

Dell EMC SRDF

Dell EMC TimeFinder SnapVX
Information Storage and Management (ISM) v4
Page 660
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts In Practice
Concepts in Practice
Dell EMC NetWorker

Software that centralizes, automates, and accelerates data backup and
recovery

Delivers enterprise-class performance and security to meet even the most
demanding service level requirements

Supports source-based and target-based deduplication capabilities by
integrating with Dell EMC Avamar and Dell EMC Data Domain respectively
Dell EMC Avamar

Disk-based backup and recovery solution that provides inherent source-based
deduplication

Uses variable-length deduplication, which significantly reduces backup time by
only storing unique daily changes

Provides various options for backup, including guest OS-level backup and
image-level backup

Data is encrypted and deduplicated to secure and minimize the network
bandwidth consumption
Dell EMC Data Domain

A target-based data deduplication solution

Data Domain Boost software increases the backup performance by distributing
parts of deduplication process to the backup server

Provides secure multitenancy
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 661
Concepts in Practice Lesson

Supports backup and archive in a single system

Supports low-cost disaster recovery to the cloud
Dell EMC Integrated Data Protection Appliance

Pre-integrated protection storage and software for comprehensive, modern
protection and faster time to value

Extends data protection seamlessly to private and public clouds

Flash-enabled for faster performance and instant recoverability

Protection for modern applications and optimized for VMware virtual
Environments
Dell EMC SRDF

Remote replication solution that provides DR and data mobility solutions for
PowerMax (VMAX) storage system

Provides the ability to maintain multiple, host-independent, remotely mirrored
copies of data
SRDF family includes:

SRDF/S and SRDF/A

SRDF/DM

SRDF/AR

Concurrent and Cascaded SRDF
Dell EMC TimeFinder SnapVX

Creates a PIT copy of a source LUN

Uses redirect on first write technology
Information Storage and Management (ISM) v4
Page 662
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson

Provides a new option to secure snaps against accidental or internal deletion

Provides instant restore which means when a LUN level restore is initiated, the
restored view is available immediately
Dell EMC NetWorker
Backup and recovery software which centralizes, automates, and accelerates data
backup and recovery operations. The following are key features of NetWorker:

Supports heterogeneous platforms such as Windows, UNIX, Linux, and also
virtual environments

Supports different backup targets – tapes, disks, Data Domain purpose-built
backup appliance, and virtual tapes

Supports multiplexing (or multi-streaming) of data

Delivers enterprise-class performance and security to meet even the most
demanding service level requirements

Provides both source-based and target-based deduplication capabilities by
integrating with DELL EMC Avamar and DELL EMC Data Domain respectively

The cloud-backup option in NetWorker enables backing up data to public cloud
configurations
Dell EMC Avamar
A disk-based backup and recovery solution that provides inherent source-based
data deduplication. With its unique global data deduplication feature, Avamar
differs from traditional backup and recovery solutions by identifying and storing only
unique sub-file data. Avamar employs variable-length deduplication, which
significantly reduces backup time by only storing unique daily changes while
maintaining daily full backups for immediate, single-step restore.
DELL EMC Avamar provides a variety of options for backup, including guest OSlevel backup and image-level backup. The three major components of an Avamar
system include Avamar server, Avamar backup clients, and Avamar administrator.
Avamar server provides the essential processes and services required for client
access and remote system administration. The Avamar client software runs on
each compute system that is being backed up. Avamar administrator is a user
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 663
Concepts in Practice Lesson
management console application that is used to remotely administer an Avamar
system.
DELL EMC Data Domain
DELL EMC Data Domain deduplication storage systems continue to revolutionize
disk backup, archiving, and disaster recovery with high-speed, inline deduplication.
DELL EMC Data Domain deduplication storage system is a target-based data
deduplication solution. Using high-speed, inline deduplication technology, the Data
Domain system provides a storage footprint that is significantly smaller on average
than that of the original data set.
DELL EMC Data Domain Boost software significantly increases backup
performance by distributing the parts of the deduplication process to the backup
server. With Data Domain Boost, only unique, compressed data segments are sent
to a Data Domain system. For archiving and compliance solutions, Data Domain
systems allow customers to cost-effectively archive non-changing data while
keeping it online for fast, reliable access and recovery.
DELL EMC Data Domain Extended Retention is a solution for long-term retention
of backup data. It is designed with an internal tiering approach to enable costeffective, long-term retention of data on disk by implementing deduplication
technology. Data Domain provides secure multi-tenancy that enables data
protection-as-a-service for large enterprises and service providers who are looking
to offer services based on Data Domain in a private or public cloud. With secure
multi-tenancy, a Data Domain system will logically isolate tenant data, ensuring that
each tenant’s data is only visible and accessible to them.
DELL EMC Data Domain Replicator software transfers only the deduplicated and
compressed unique changes across any IP network, requiring a fraction of the
bandwidth, time, and cost, compared to traditional replication methods. Data
Domain Cloud DR (DD CDR) allows enterprises to copy backed-up VMs from their
on-premise Data Domain and Avamar environments to the public cloud.
Dell EMC Integrated Data Protection Appliance
A pre-integrated, turnkey solution that is simple to deploy and scale, provides
comprehensive protection for a diverse application ecosystem, and comes with
native cloud tiering for long-term retention. IDPA combines protection storage,
Information Storage and Management (ISM) v4
Page 664
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
protection software, search, and analytics to reduce the complexity of managing
multiple data silos, point solutions, and vendor relationships.
IDPA is an innovative solution that provides support for modern applications like
MongoDB and MySQL, and is optimized for VMware. It is also built on industry
proven data invulnerability architecture, delivering encryption, fault detection, and
healing.
Dell EMC SRDF
SRDF, which stands for Symmetrix Remote Data Facility), is a family of software
that is the industry standard for remote replication in mission-critical environments.
Built for the industry-leading highend PowerMax (VMAX) hardware architecture, the
SRDF family of solutions is trusted globally for disaster recovery and business
continuity.
The SRDF family offers unmatched deployment flexibility and massive scalability to
deliver a wide range of distance replication capabilities.
SRDF consists of the following options:

SRDF/S (synchronous option for zero data exposure loss)

SRDF/A (asynchronous option for extended distances)

SRDF/Star (multi-site replication option)

SRDF/CG (consistency groups for federated data sets across arrays)

SRDF/Metro (for active/active data center protection)
Dell EMC TimeFinder SnapVX
Enables zero-impact snapshots, simple user-defined names, faster and secure
snapshot creation/expiration, cascading, compatibility with SRDF, and support for
legacy VMAX replication modes. SnapVX reduces replication storage costs by up
to 10x and is optimized for cloud scale with its highly efficient snaps. Customers
can take up to 256 snapshots and establish up to 1024 target volumes per source
device, providing read/write access as pointer (snap) or full (clone) copies.
SnapVX also provides a new option to secure snaps against accidental or internal
deletion. It provides instant restore which means when a LUN level restore is
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 665
Concepts in Practice Lesson
initiated, the restored view is available immediately. Snapshot provides point-intime data copies for backups, testing, decision support, and data recovery.
Information Storage and Management (ISM) v4
Page 666
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Dell EMC RecoverPoint

Enable continuous data protection for any PIT recovery to optimize RPO and
RTO

Ensure recovery consistency for interdependent applications

Provide synchronous or asynchronous replication policies

Reduce WAN bandwidth consumption and utilize available bandwidth optimally

Offer multisite support
Dell EMC Power Vault

Simplifies data backup and archive by easily integrating the LTO family of tape
drives into your data center

It’s lower power consumption makes it an ideal part of a cloud physical
infrastructure build-out

Linear Tape File System (LTFS) support removes software incompatibilities,
creating portability between different vendors and operating systems
Dell EMC SourceOne

Archiving software that helps organizations to archive aging emails, files, and
the Microsoft SharePoint content to the appropriate storage tiers
SourceOne family of products includes:

DELL EMC SourceOne Email Management

DELL EMC SourceOne for Microsoft SharePoint

DELL EMC SourceOne for File Systems

DELL EMC SourceOne Email Supervisor
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 667
Concepts in Practice Lesson
VMware vCloud Air Disaster Recovery
Recovery-as-a-service offering which:

Provides simple, affordable protection in the cloud for your vSphere
environment

Offers enhanced recovery times for business and mission-critical applications
running on vSphere

Offers scalable disaster recovery protection capacity in the cloud to address the
changing business requirements
VMware vMotion

Performs live migration of a running VM from one physical server to another,
without any downtime

VM retains its network identity and connections, ensuring a seamless migration
process

Enables to perform maintenance without disrupting business operations
VMware Storage vMotion

Enables live migration of VM disk files within and across storage systems
without any downtime

Performs zero-downtime storage migrations with complete transaction integrity

Migrates the disk files of VMs running any supported operating system on any
supported server hardware
Dell EMC RecoverPoint
Provides continuous data protection for comprehensive operational and disaster
recovery. It supports major 3rd party arrays via VPLEX.
Information Storage and Management (ISM) v4
Page 668
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
RecoverPoint delivers benefits including the ability to:

Enable continuous data protection for any PIT recovery to optimize RPO and
RTO

Ensure recovery consistency for interdependent applications

Provide synchronous or asynchronous replication policies

Reduce WAN bandwidth consumption and utilize available bandwidth optimally

Offer multisite support
Dell EMC PowerVault
Simplifies data backup and archive by easily integrating the LTO family of tape
drives into your data center. Supporting TBs of native capacity on a single
cartridge, LTO drives provide decades of shelf life for industries and tasks that
need reliable, long-term, large-capacity data retention, such as:

Healthcare imaging

Media and entertainment

Video surveillance

Geophysical (oil and gas) data

Computational analysis, such as genome mapping and event simulations
Its lower power consumption makes it an ideal part of a cloud physical
infrastructure build-out. Linear Tape File System (LTFS) support removes software
incompatibilities, creating portability between different vendors and operating
systems to extend the life of your infrastructure investments.
Dell EMC SourceOne
A family of archiving software. It helps organizations to reduce the burden of aging
emails, files, and Microsoft SharePoint content by archiving them to the appropriate
storage tier. SourceOne helps in meeting the compliance requirements by
managing emails, files, and SharePoint content as business records and enforcing
retention/disposition policies.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 669
Concepts in Practice Lesson
The SourceOne family of products includes:

DELL EMC SourceOne Email Management for archiving email messages and
other items

DELL EMC SourceOne for Microsoft SharePoint for archiving SharePoint
content

DELL EMC SourceOne for File Systems for archiving files from file servers

DELL EMC SourceOne Email Supervisor for monitoring corporate email policy
compliance
VMware vCloud Air Disaster Recovery
A DRaaS offering owned and operated by VMware, built on vSphere Replication
and vCloud Air – a hybrid cloud platform for infrastructure-as-a-service (IaaS).
Disaster Recovery leverages vSphere Replication to provide robust, asynchronous
replication capabilities at the hypervisor layer. This approach towards replication
helps in easy configuration of virtual machines in vSphere for disaster recovery,
without depending on underlying infrastructure hardware or data center mirroring.
Per-virtual-machine replication and restore granularity further provide the ability to
meet dynamic recovery objectives without overshooting the actual business
requirements for disaster recovery as they change.
VMware vMotion
Performs live migration of a running virtual machine from one physical server to
another, without downtime. The virtual machine retains its network identity and
connections, ensuring a seamless migration process. Transferring the virtual
machine's active memory and the precise execution state over a high-speed
network, allows the virtual machine to move from one host to another. This entire
process takes less time on a gigabit Ethernet network.
vMotion provides the following benefits:

Perform hardware maintenance without scheduling downtime or disrupting
business operations

Move virtual machines away from failing or underperforming servers

Allows vSphere DRS to balance VMs across hosts
Information Storage and Management (ISM) v4
Page 670
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
VMware Storage vMotion
Enables live migration of virtual machine disk files within and across storage
systems without service disruptions. Storage vMotion performs zero-downtime
storage migrations with complete transaction integrity. It migrates the disk files of
virtual machines running any supported operating system on any supported server
hardware. It performs live migration of virtual machine disk files across any Fibre
Channel, iSCSI, FCoE, and NFS storage system supported by VMware vSphere. It
allows to redistribute VMs or virtual disks to different storage systems or volumes to
balance capacity or improve performance.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 671
Concepts in Practice Lesson
Assessment
1. Which is a period during which a production volume is available to perform
backup?
A. RTO
B. RPO
C. Backup Window
D. Backup Media
2. Which provides the ability to create fully populated point-in-time copies of LUNs
within a storage system or create a copy of an existing VM?
A. Clone
B. Snapshot
C. Pointer-based virtual replica
D. LUN masking
3. Which factor impacts the deduplication ratio in a backup environment?
A. Retention period
Information Storage and Management (ISM) v4
Page 672
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
B. Type of backup media
C. Type of backup server
D. Value of data
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 673
Summary
Summary
Information Storage and Management (ISM) v4
Page 674
© Copyright 2019 Dell Inc.
Storage Infrastructure Security
Introduction
This module focuses on information security goals and key terminologies. This
module also focuses on the three storage security domains and key threats across
the domains. Further, this module focuses on the various security controls that
enable an organization to mitigate these threats. Finally, this module focuses on
the governance, risk, and compliance (GRC) aspect in a data center environment.
Upon completing this module, you will be able to:
 Explain information security goals and terminologies
 List storage security domains and threats in storage infrastructure
 Describe governance, risk, and compliance
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 675
Introduction to Information Security Lesson
Introduction to Information Security Lesson
Introduction
This lesson covers goals of information security, security concepts and their
relations, and defense-in-depth strategy. The lesson also focuses on the
governance, risk, and compliance (GRC) aspect in a data center environment.
This lesson covers the following topics:

Goals of information security

Security concepts

Defense-in-depth strategy

Governance, Risk and Compliance
Information Storage and Management (ISM) v4
Page 676
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Introduction to Information Security
Introduction to Information Security
Definition: Information Security
It includes a set of practices that protect information and information
systems from unauthorized access, use, destruction, deletion,
modification, and disruption.
Source: US Federal law (Title 38 Part IV, Chapter 57, Subchapter III
USC 5727)

Information is an organization’s most valuable asset

Organizations are transforming to modern technologies infrastructure
 Cloud is one of the core elements of the modern technologies
 Trust is one of the key concerns for consumers using modern technologies
o Trust = Visibility + Control

Securing infrastructure is important for the platform of most of the technological
environment
Notes
Information is an organization’s most valuable asset. This information, including
intellectual property, personal identities, and financial transactions, is routinely
processed and stored in storage systems, which are accessed through the
network. As a result, storage is now more exposed to various security threats that
can potentially damage business-critical data and disrupt critical services.
Organizations deploy various tools within their infrastructure to protect the asset.
These tools must be deployed on various infrastructure assets, such as compute
(processes information), storage (stores information), and network (carries
information) to protect the information.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 677
Introduction to Information Security Lesson
As organizations are adopting modern technologies, in which cloud is a core
element, one of the key concerns they have is ‘trust’. Trust depends on the degree
of control and visibility available to the information’s owner. Therefore, securing
storage infrastructure has become an integral component of the storage
management process in modern technological environment. It is an intensive and
necessary task, essential to manage, and protect vital information.
Information security includes a set of practices that protect information and
information systems from unauthorized disclosure, access, use, destruction,
deletion, modification, and disruption.
Information security involves implementing various kinds of safeguards or controls
to lessen the risk of an exploitation or a vulnerability in the information system. The
risk and the vulnerabilities could otherwise cause a significant impact to
organization’s business. From this perspective, security is an ongoing process, not
static, and requires continuous re-validation and modification. Securing the storage
infrastructure begins with understanding the goals of information security.
Information security is vital for every business organization.
Information Storage and Management (ISM) v4
Page 678
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Goals of Information Security
Confidentiality
C
Ensures the secrecy of information
Integrity
I
Ensures no unauthorized changes to the information
Availability
A
Ensures that the resources are always available to authorized
users
Accountability
A
Users or the applications are responsible for the
actions
The goals of information security are:

CIA
 Confidentiality
 Integrity
 Availability

Accountability
Notes
The goal of information security is to provide Confidentiality, Integrity, and
Availability, commonly referred to as the security triad, or CIA:

Confidentiality provides the required secrecy of information to ensure that only
authorized users have access to data.

Integrity ensures that unauthorized changes to information are not allowed. The
objective of ensuring integrity is to detect and protect against unauthorized
alteration or deletion of information.

Availability ensures that authorized users have reliable and timely access to
compute, storage, network, application, and data resources.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 679
Introduction to Information Security Lesson
Ensuring confidentiality, integrity, and availability are the primary objective of any IT
security implementation. These goals are supported by using authentication,
authorization, and auditing processes.
Accountability is another important principle of information security. It refers to the
process where the users or applications are responsible for the actions or events
that are executed on the systems. Accountability can be achieved by auditing logs.
Information Storage and Management (ISM) v4
Page 680
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Authentication, Authorization, and Auditing
Authentication
Process to ensure ‘users’ or ‘assets’ are who they claim to
be
Authorization
Process to determine the privileges that a user has, example:
read/write or read only
Auditing
Logging of all transactions to assess the effectiveness of the
security controls
Notes
Authentication, authorization, and auditing also referred as AAA plays an important
role in protecting the customers data in a multitenant cloud environment:

Authentication is a process to ensure that ‘users’ or ‘assets’ are who they claim
to be by verifying their identity credentials. The user has to prove identity to the
provider to access the data stored. A user may be authenticated using a singlefactor or multifactor method. Single-factor authentication involves the use of
only one factor, such as a password. Multifactor authentication uses more than
one factor to authenticate a user.

Authorization is a process of determining the privileges that a
user/device/application has, to access a particular service or a resource. For
example, a user with administrator’s privileges is authorized to access more
services or resources compared to a user with non-administrator privileges. For
example, the administrator can have ‘read/write’ access and a normal user can
have ‘read-only’ access. Authorization should be performed only if the
authentication is successful. The most common authentication and
authorization controls, used in a data center environment are Windows Access
Control List (ACL), UNIX permissions, Kerberos, and Challenge-Handshake
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 681
Introduction to Information Security Lesson
Authentication Protocol (CHAP). It is essential to verify the effectiveness of
security controls that are deployed with the help of auditing.

Auditing refers to the logging of all transactions for the purpose of assessing the
effectiveness of security controls. It helps to validate the behavior of the
infrastructure components, and to perform forensics, debugging, and monitoring
activities.
For example: In cloud computing, a customer can access the cloud service catalog
using the credentials. Once the customer is authenticated, a different view of the
catalog is provided along with different options, based on the privileges assigned.
Administrator can have a different view of the catalog compared to a normal user.
The number of times a customer has logged in to the catalog is audited for
monitoring purposes.
Information Storage and Management (ISM) v4
Page 682
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Security Concepts and Relationships
Threat Agent
Gives rise to
Threat
Wish to
abuse/or may
damage
That exploits
Owner
Vulnerabilities
Leading to
Risk
Countermeasures
To
To
reduce
Imposes
Asset
Values
Notes
The figure shows relationship among various security concepts in a data center
environment. An organization (owner of the asset) wants to safeguard the asset
from threat agents (attackers) who seek to abuse the assets. Risk arises when the
likelihood of a threat agent (an attacker) to exploit the vulnerability arises.
Therefore, the organizations deploy various countermeasures to minimize risk by
reducing the vulnerabilities.
Risk assessment is the first step to determine the extent of potential threats and
risks in an infrastructure. The process assesses risk and helps to identify
appropriate controls to mitigate or eliminate risks. Organizations must apply their
basic information security and risk-management policies and standards to their
infrastructure.
Some of the key security areas that an organization must focus on while building
the infrastructure are: authentication, identity and access management, data loss
prevention and data breach notification, governance, risk, and compliance (GRC),
privacy, network monitoring and analysis, security information and event logging,
incident management, and security management.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 683
Introduction to Information Security Lesson
Security Concepts
The following are important security concepts:
Security Assets

Information, hardware, and software

Security considerations:
 Must provide easy access to authorized users
 Must be difficult for potential attackers to compromise
 Cost of securing the assets should be a fraction of the value of the assets
Security Threats

Potential attacks that can be carried out

Attacks can be classified as:
 Passive attacks attempt to gain unauthorized access into the system
 Active attacks attempt data modification, Denial of Service (DoS), and
repudiation attacks
Security Vulnerabilities

A weaknesses that an attacker exploits to carry out attacks

Security considerations:
 Attack surface
 Attack vectors
 Work factor

Managing vulnerabilities:
 Minimize the attack surface
 Maximize the work factor
 Install security controls
Information Storage and Management (ISM) v4
Page 684
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Security Controls

Reduce the impact of vulnerabilities

Controls can be:
 Technical: antivirus, firewalls, and IDPS
 Non-technical: administrative policies and physical controls

Controls are categorized as:
 Preventive
 Detective
 Corrective
Security Assets Notes
Information is one of the most important assets for any organization. Other assets
include hardware, software, and other infrastructure components required to
access the information. To protect these assets, organizations deploy security
controls. These security controls have two objectives.

The first objective is to ensure that the resources are easily accessible to
authorized users.

The second objective is to make it difficult for potential attackers to access and
compromise the system.
The effectiveness of a security control can be measured by two key criteria. One,
the cost of implementing the system should be a fraction of the value of the
protected data. Two, it should cost heavily to a potential attacker, in terms of
money, effort, and time, to compromise and access the assets.
Security Threats Notes
Threats are the potential attacks that can be carried out on an IT infrastructure.
These attacks can be classified as active or passive. Passive attacks are attempts
to gain unauthorized access into the system. Passive attacks pose threats to
confidentiality of information. Active attacks include data modification, denial of
service (DoS), and repudiation attacks. Active attacks pose threats to data integrity,
availability, and accountability.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 685
Introduction to Information Security Lesson
Security Vulnerabilities Notes
Vulnerability is a weakness of any information system that an attacker exploits to
carry out an attack. The components that provide a path enabling access to
information are vulnerable to potential attacks. It is important to implement
adequate security controls at all the access points on these components.
Attack surface, attack vector, and work factor are the three factors to consider
when assessing the extent to which an environment is vulnerable to security
threats. Attack surface refers to the various entry points that an attacker can use to
launch an attack, which includes people, process, and technology. For example,
each component of a storage infrastructure is a source of potential vulnerability. An
attack vector is a step or a series of steps necessary to complete an attack. For
example, an attacker might exploit a bug in the management interface to execute a
snoop attack. Work factor refers to the amount of time and effort required to exploit
an attack vector.
Having assessed the vulnerability of the environment, organizations can deploy
specific control measures. Any control measure should account for three aspects:
people, process, technology, and the relationships among them.
Security Controls Notes
The security controls are directed at reducing vulnerability by minimizing the attack
surfaces and maximizing the work factors. These controls can be technical or nontechnical. Controls are categorized as preventive, detective, and corrective.

Preventive: Avoid problems before they occur

Detective: Detect a problem that has occurred

Corrective: Correct the problem that has occurred
Organizations should deploy defense-in-depth strategy when implementing the
controls.
Information Storage and Management (ISM) v4
Page 686
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Defense-in-Depth
Definition: Defense-in-Depth
A strategy in which multiple layers of defense are deployed
throughout the infrastructure to help mitigate the risk of security
threats in case one layer of the defense is compromised.
Storage Security
(Encryption, Zoning, etc.)
Compute Security
(Hardening, Malware Protection Software, etc.)
Network Security
(Firewall, DMZ, etc.)
Remote Access Control
(VPN, Authentication, etc.)
Perimeter Security
(Physical Security)

Also known as a “layered approach” to security

Provides organizations additional time to detect and respond to an attack
 Reduces the scope of a security breach
Notes
An organization should deploy multiple layers of defense throughout the
infrastructure to mitigate the risk of security threats, in case one layer of the
defense is compromised. This strategy is referred to as defense-in-depth. This
strategy may also be thought of as a “layered approach to security” because there
are multiple measures for security at different levels. Defense-in-depth increases
the barrier to exploitation—an attacker must breach each layer of defenses to be
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 687
Introduction to Information Security Lesson
successful—and thereby provides additional time to detect and respond to an
attack.
This potentially reduces the scope of a security breach. However, the overall cost
of deploying defense-in-depth is often higher compared to single-layered security
controls. An example of defense-in-depth could be a virtual firewall installed on a
hypervisor when there is already a network-based firewall deployed within the
same environment. This provides additional layer of security reducing the chance
of compromising hypervisor’s security if network-level firewall is compromised.
Information Storage and Management (ISM) v4
Page 688
© Copyright 2019 Dell Inc.
Introduction to Information Security Lesson
Governance, Risk, and Compliance
Definition: GRC
A term encompassing processes that help an organization to ensure
that their acts are ethically correct and in accordance with their risk
appetite (the risk level an organization chooses to accept), internal
policies, and external regulations.

GRC work together to enforce policies and minimize risks
Governance
Authority for making
policies
Risk Management
Restricting access to
certain users
Compliance
Assures policies are
being enforced
Notes
GRC should be integrated, holistic, and organization-wide. All operations of an
organization should be managed and supported through GRC. Governance, risk
management, and compliance management work together to enforce policies and
minimize potential risks. To better understand how these three components work
together, consider an example of how GRC is implemented in an IT organization.
Governance is the authority for making policies such as defining access rights to
users based on their roles and privileges. Risk management involves identifying
resources that should not be accessed by certain users in order to preserve
confidentiality, integrity, and availability. In this example, compliance management
assures that the policies are being enforced by implementing controls such as
firewalls and identify management systems.
GRC is an important component of data center infrastructure. Therefore, while
using modern technologies infrastructure organizations must ensure that all
aspects of GRC are deployed that include cloud-related aspects such as ensuring
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 689
Introduction to Information Security Lesson
secured multi-tenancy, the jurisdictions where data should be stored, data privacy,
and ownership.
Information Storage and Management (ISM) v4
Page 690
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson
Storage Security Domains and Threats Lesson
Introduction
This lesson covers the storage security domains and the key security threats
across domains.
This lesson covers the following topics:

Storage security domains

Key security threats across domains
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 691
Storage Security Domains and Threats Lesson
Storage Security Domains and Threats
Storage Security Domains
The information made available on a network is exposed to security threats from
various of sources. Therefore, specific controls must be implemented to secure this
information that is stored on an organization’s storage infrastructure.
The illustration depicts the three security domains of a storage environment.
Management
Access
Backup, Replication, and Archive
Application
Access
Storage Network
Secondary Storage
Data
Storage
Storage Security Domains Notes

To deploy controls, it is important to have a clear understanding of the access
paths leading to storage resources. If each component within the infrastructure
is considered a potential access point, the attack surface of all these access
points must be analyzed to identify the associated vulnerabilities.
Information Storage and Management (ISM) v4
Page 692
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson

To identify the threats that apply to a storage infrastructure, access paths to
data storage can be categorized into three security domains: application
access, management access, and backup, replication, and archive.

To secure the storage environment, identify the attack surface and existing
threats within each of the security domains and classify the threats based on
the security goals—availability, confidentiality, and integrity.
Storage Security Domains Illustration Notes
In the illustration:

The first security domain involves application access to the stored data through
the storage network. Application access domain may include only those
applications that access the data through the file system or a database
interface.

The second security domain includes management access to storage and
interconnecting devices and to the data residing on those devices. Management
access, whether monitoring, provisioning, or managing storage resources, is
associated with every device within the storage environment. Most
management software supports some form of CLI, system management
console, or a web-based interface. Implementing appropriate controls for
securing management applications is important because the damage that can
be caused by using these applications can be far more extensive.

The third domain consists of backup, replication, and archive access. This
domain is primarily accessed by storage administrators who configure and
manage the environment. Along with the access points in this domain, the
backup and replication media also needs to be secured.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 693
Storage Security Domains and Threats Lesson
Key Security Threats Across Domains

Some of the key security threats across domains are
– Denial of services (DoS)
– Distributed denial of service attack (DDoS)
– Loss of data
– Malicious insiders
– Account hacking
– Shared technology vulnerabilities
Information Storage and Management (ISM) v4
Page 694
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson
Denial of Services (DoS)

Prevents legitimate users from accessing resources or services
 Example: Exhausting network bandwidth or CPU cycles
 Could be targeted against compute systems, networks, and storage
resources

DDoS is a variant of DoS attack
 Several systems launch a coordinated DoS attack on target(s)
 DDoS master program is installed on a compute system
 Master program communicates to agents at designated time
 Agents initiate the attack on receiving the command

Control measure
 Impose restrictions and limits on resource consumption
Notes
Prevents legitimate users from accessing resources or services. DoS attacks can
be targeted against compute systems, networks, or storage resources in a storage
environment. Always, the intent of DoS is to exhaust key resources, such as
network bandwidth or CPU cycles, thus impacting production use. For example, an
attacker may send massive quantities of data over the network to the storage
system with the intention of consuming bandwidth. This prevents legitimate users
from using the bandwidth and the user may not be able to access the storage
system over the network. Such an attack may be carried out by exploiting
weaknesses of a communication protocol. For example, an attacker may cause
DoS to a legitimate user by resetting TCP sessions. Apart from DoS attack, an
attacker may also carry out Distributed DoS attack.
A Distributed DoS (DDoS) attack is a variant of DoS attack in which several
systems launch a coordinated, simultaneous DoS attack on their target(s). It results
into denial of service to the users of the targeted system(s). In a DDoS attack, the
attacker can multiply the effectiveness of the DoS attack by harnessing the
resources of multiple collaborating systems which serve as attack platforms.
Typically, a DDoS master program is installed on one compute system. Then, at a
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 695
Storage Security Domains and Threats Lesson
designated time, the master program communicates to a number of "agent"
programs installed on compute systems. When the agents receive the command,
they initiate the attack.
The principal control that can minimize the impact of DoS and DDoS attack is to
impose restrictions and limits on the network resource consumption. For example,
when it is identified that the amount of data being sent from a given IP address
exceeds the configured limits, the traffic from that IP address may be blocked. This
provides a first line of defense. Further, restrictions and limits may be imposed on
resources consumed by each compute system, providing an additional line of
defense.
Information Storage and Management (ISM) v4
Page 696
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson
Loss of Data

Occurs due to various reasons other than malicious attacks

Causes of data loss include:
 Accidental deletion by an administrator
 Destruction resulting from natural disasters

If organization is a service provider then they should publish
 Protection controls deployed for data protection
 Appropriate terms/conditions and penalties related to data loss

Control measure
 Data backup and replication
Notes
Data loss can occur in a storage environment due to various reasons other than
malicious attacks. Some of the causes of data loss may include accidental deletion
by an administrator or destruction resulting from natural disasters. In order to
prevent data loss, deploying appropriate measures such as data backup or
replication can reduce the impact of such events. Organizations need to develop
strategies that can avoid or at least minimize the data loss due to such events.
Examples of such strategies include choice of backup media, frequency of backup,
synchronous/asynchronous replication, and number of copies.
Further, if the organization is a cloud service provider then they must publish the
protection controls deployed to protect the data stored in cloud. The providers must
also ensure appropriate terms and conditions related to data loss and the
associated penalties as part of the service contract. The service contract should
also include various BC/DR options, such as backup and replication, offered to the
consumers.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 697
Storage Security Domains and Threats Lesson
Malicious Insiders
Definition: Malicious Insiders
An organization’s current or former employee, contractor, or other
business partner who has or had authorized access to an
organization's compute systems, network, or storage.
Source: Computer Emergency Response Team (CERT)

Intentional misuse of access to negatively impact CIA

Control measures:
 Strict access control policies
 Security audit and data encryption
 Disable employee accounts immediately after separation
 Segregation of duties (role-based access control)
 Background investigation of candidates before hiring
Notes
Today, most organizations are aware of the security threats posed by outsiders.
Countermeasures such as firewalls, malware protection software, and intrusion
detection systems can minimize the risk of attacks from outsiders. However, these
measures do not reduce the risk of attacks from malicious insiders.
According to Computer Emergency Response Team (CERT), a malicious insider
could be an organization’s current or former employee, contractor, or other
business partner who has or had authorized access to an organization’s compute
systems, network, or storage. These malicious insiders may intentionally misuse
that access in ways that negatively impact the confidentiality, integrity, or
availability of the organization’s information or resources.
For example, consider a former employee of an organization who had access to
the organization’s storage resources. This malicious insider may be aware of
security weaknesses in that storage environment. This is a serious threat because
Information Storage and Management (ISM) v4
Page 698
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson
the malicious insider may exploit the security weakness. Control measures that can
minimize the risk due to malicious insiders include strict access control policies,
disabling employee accounts immediately after separation from the company,
security audit, encryption, and segregation of duties (role-based access control,
which is discussed later in this module). A background investigation of a candidate
before hiring is another key measure that can reduce the risk due to malicious
insiders.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 699
Storage Security Domains and Threats Lesson
Account Hacking

Occurs when an attacker gains access to administrator’s/user’s accounts

Controls measures: multi-factor authentication, IPSec, IDPS, and firewall
Type of attack
Description
Phishing

Social engineering attack used to deceive
users

Carried out by spoofing email containing
link to a fake website

Users credentials entered on the fake site
are captured

Attacker installs malware in administrator’s
or user’s compute system

Malware captures users credentials and
sends to the attacker

Attacker eavesdrops on the network to
capture credential
Installing keystroke-logging
malware
Man-in-the-middle
Notes
Account hijacking refers to a scenario in which an attacker gains access to an
administrator’s or user’s account(s) using methods such as phishing or installing
keystroke-logging malware on administrator’s or user’s compute systems.
Phishing is an example of a social engineering attack that is used to deceive users.
Phishing attacks are typically carried out by spoofing email – an email with a fake
but genuine-appearing address, which provides a link to a website that
masquerades as a legitimate website. After opening the website, users are asked
to enter details such as their login credentials. These details are then captured by
Information Storage and Management (ISM) v4
Page 700
© Copyright 2019 Dell Inc.
Storage Security Domains and Threats Lesson
the attacker to take over the user’s account. For example, an employee of an
organization may receive an email that is designed to appear as if the IT
department of that organization has sent it. This email may ask the users to click
the link provided in the email and update their details. After clicking the email, the
user is directed to a malicious website where their details are captured.
Another way to gain access to a user’s credentials is by installing keystroke-logging
malware. In this attack, the attacker installs malware in the storage administrator’s
compute system which captures user credentials and sends them to the attacker.
After capturing the credentials, an attacker can use them to gain access to the
storage environment. The attacker may then eavesdrop on the administrator’s
activities and may also change the configuration of the storage environment to
negatively impact the environment.
A “man-in-the-middle” attack is another way to hack user’s credentials. In this
attack, the attacker eavesdrops—overhears the conversation—on the network
channel between two sites when replication is occurring over the network. Use of
multi-factor authentication and IPSec (a suite of algorithms, protocols, and
procedures used for securing IP communications by authenticating and/or
encrypting each packet in a data stream) can prevent this type of attack.
Intrusion detection and prevention systems and firewalls are additional controls that
may reduce the risk of such attacks.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 701
Storage Security Domains and Threats Lesson
Shared Technologies Vulnerabilities

An attacker may exploit the vulnerabilities of tools used to enable multi-tenant
environments

Examples of threats:
 Failure of controls that provide separation of memory and storage
 Hyperjacking attack involves installing a rogue hypervisor that takes control
of compute system

Control measure:
 Examining program memory and processor registers for anomalies
Notes
Technologies that are used to build today’s storage infrastructure provide a multitenant environment enabling the sharing of resources. Multi-tenancy is achieved by
using controls that provide separation of resources such as memory and storage
for each application. Failure of these controls may expose the confidential data of
one business unit to users of other business units, raising security risks.
Compromising a hypervisor is a serious event because it exposes the entire
environment to potential attacks. Hyperjacking is an example of this type of attack
in which the attacker installs a rogue hypervisor that takes control of the compute
system. The attacker now can use this hypervisor to run unauthorized virtual
machines in the environment and carry out further attacks. Detecting this attack is
difficult and involves examining components such as program memory and the
processor core registers for anomalies.
Information Storage and Management (ISM) v4
Page 702
© Copyright 2019 Dell Inc.
Security Controls Lesson
Security Controls Lesson
Introduction
This lesson covers physical security and focuses on key security controls.
This lesson covers the following topics:

Physical security

Key security controls
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 703
Security Controls Lesson
Security Controls
Introduction to Security Controls
Any security control should account for three aspects: people, process, and
technology, and the relationships among them.
Security controls can be classified as

Administrative
 Include security and personnel policies or standard procedures to direct the
safe execution of various operations

Technical
 Usually implemented through tools or devices deployed on the IT
infrastructure
Technical security controls must be deployed at

Compute level

Network level

Storage level
Information Storage and Management (ISM) v4
Page 704
© Copyright 2019 Dell Inc.
Security Controls Lesson
Key Security Controls
Important security controls include:

Physical security

Identity and access management

Role-based access control

Firewall

Intrusion detection and prevention system

Virtual private network

Malware protection software

Data encryption

Data shredding
Notes
At the compute system level, security controls are deployed to secure hypervisors
and hypervisor management systems, virtual machines, guest operating systems,
and applications. Security at the network level commonly includes firewalls,
demilitarized zones, intrusion detection and prevention systems, virtual private
networks, and VLAN. At the storage level, security controls include data shredding,
and data encryption. Apart from these security controls, the storage infrastructure
also requires identity and access management, role-based access control, and
physical security arrangements.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 705
Security Controls Lesson
Physical Security
Physical security is the foundation of any overall IT security strategy. Strict
enforcement of policies, processes, and procedures by an organization is critical
element of successful physical security.
The physical security measures that are deployed to secure the organization’s
storage infrastructure are:

Disabling all unused devices and ports

24/7/365 onsite security

Biometric or security badge-based authentication to grant access to the facilities

Surveillance cameras to monitor activity throughout the facility

Sensors and alarms to detect motion and fire
Information Storage and Management (ISM) v4
Page 706
© Copyright 2019 Dell Inc.
Security Controls Lesson
Identity and Access Management
Definition: Identity and Access Management (IAM)
A process of managing users identifiers, and their authentication and
authorization to access storage infrastructure resources.

IAM controls access to resources by placing restrictions based on user
identities

An organization may collaborate with one or more cloud service providers to
access various cloud-based storage services
 Requires deploying multiple authentication systems to enable the
organization to authenticate employees and provide access to cloud-based
storage services.
Organizations may deploy the following authorization and authentication controls:
Control
Description
Examples
Authorization
Restricts accessibility and Windows ACLs, UNIX
sharing of files and
permission, and OAuth
folders
Authentication
Enables authentication
amount client and server
Multi-factor authentication,
Kerberos, CHAP, and
OpenID
Notes
The key traditional authentication and authorization controls that are deployed in a
storage environment are Windows ACLs, UNIX permissions, Kerberos, and
Challenge-Handshake Authentication Protocol (CHAP). Alternatively, the
organization can use Federated Identity Management (FIM) for authentication. A
federation is an association of organizations (referred to as trusted parties) that
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 707
Security Controls Lesson
come together to exchange information about their users and resources to enable
collaboration.
Federation includes the process of managing the trust relationships among the
trusted parties beyond internal networks or administrative boundaries. FIM enables
the organizations (especially cloud service providers) to offer services without
implementing their own authentication system. The organization can choose an
identity provider to authenticate their users. This involves exchanging identity
attributes between the organizations and the identity provider in a secure way. The
identity and access management controls used by organizations include OpenID
and OAuth.
Information Storage and Management (ISM) v4
Page 708
© Copyright 2019 Dell Inc.
Security Controls Lesson
OAuth
Definition: OAuth
An open authorization control enables a client to access protected
resources from a resource server on behalf of a resource owner.
Client
1. Authorization Request
Resource Owner
2. Authorization Grant
3. Authorization Grant
Authorization
Server
4. Access Token
5. Access Token
Resource Server
6. Service Request

Can be used to secure application access domain

There are four entities that are involved in the authorization control:
 Resource owner
 Resource server
 Client
 Authorization Server

Example: Giving LinkedIn permission to access your Facebook contacts
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 709
Security Controls Lesson
Notes
The illustration shows the steps involved in OAuth process as described in Request
for Comments (RFC) 6749 published by Internet Engineering Task Force (IETF):
1. The client requests authorization from the resource owner. The authorization
request can be made directly to the resource owner, or indirectly through the
authorization server.
2. The client receives an authorization grant, which is a credential representing the
resource owner's authorization to access its protected resources. It is used by
the client to obtain an access token. Access tokens are credentials that are
used to access protected resources. An access token is a string representing
an authorization issued to the client. The string is usually opaque to the client.
Tokens represent specific scopes and durations of access, granted by the
resource owner, and enforced by the resource server and authorization server.
3. The client requests an access token by authenticating with the authorization
server and presenting the authorization grant.
4. The authorization server authenticates the client and validates the authorization
grant, and if valid, issues an access token.
5. The client requests the protected resource from the resource server and
authenticates by presenting the access token.
6. The resource server validates the access token, and if valid, serves the request.
Information Storage and Management (ISM) v4
Page 710
© Copyright 2019 Dell Inc.
Security Controls Lesson
OpenID
Definition: OpenID
An open standard for authentication in which an organization uses
authentication services from an OpenID provider.
Service Provider
Step 1
Do not require their own
authentication control
(Relying Party)
Step 4
Maintains users’ credentials
Step 2
Enables relying parties to authenticate users
Browser
User creates an ID with one of the
OpenID providers
Step 3
OpenID Provider
(Identity Provider)
User
Step 1: Login request using OpenID
Step 2: Authentication request is redirected to
OpenID provider
Step 3: Consent to profile sharing
Step 4: Authentication response is redirected to
organization providing services
Notes
The organization is known as the relying party and the OpenID provider is known
as the identity provider. An OpenID provider maintains users credentials on their
authentication system and enables relying parties to authenticate users requesting
the use of the relying party’s services. This eliminates the need for the relying party
to deploy their own authentication systems.
In the OpenID control, a user creates an ID with one of the OpenID providers. This
OpenID then can be used to sign on to any organization (relying party) that accepts
Open ID authentication. This control can be used in the modern environment to
secure application access domain.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 711
Security Controls Lesson
The illustration shows the OpenID concept by considering a user who requires
services from the relying party. For the user to use the services provided by the
relying party, an identity (user ID and password) is required. The relying party does
not provide their own authentication control, however they support OpenID from
one or more OpenID providers. The user can create an ID with the identity provider
and then use this ID with the relying party. The relying party, after receiving the
login request, authenticates it with the help of identity provider and then grants
access to the services.
Information Storage and Management (ISM) v4
Page 712
© Copyright 2019 Dell Inc.
Security Controls Lesson
Multifactor Authentication
User Login
Something you know
First Factor =BH347N12
Username
Password
PATSGR
BH347N12459820
Something you have
459820
Token
459820

Multiple factors for authentication:
 First factor: What a user knows?
o For example, a password
 Second factor: What the user has?
o For example, a token
 Third factor: Who is the user?
o For example, biometric identity

Access is granted only when all the factors are validated
Notes
Multifactor authentication uses more than one factor to authenticate a user. A
commonly implemented two-factor authentication process requires the user to
supply both something he, or she knows (such as a password) and also something
he or she has (such as a device). The second factor can be a password that is
generated by a physical device (known as token), which is in the user’s
possession. The password that is generated by the token is valid for a predefined
time. The token generates another password after the predefined time is over. To
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 713
Security Controls Lesson
further enhance the authentication process, more factors may also be considered.
Examples of more factors that may be used include biometric identity. A multifactor
authentication technique may be deployed using any combination of these factors.
A user’s access to the environment is granted only when all the required factors are
validated.
Information Storage and Management (ISM) v4
Page 714
© Copyright 2019 Dell Inc.
Security Controls Lesson
Challenge Handshake Authentication Protocol
CHAP is basic authentication control that has been widely adopted by network
devices and compute systems. It provides a method for initiators and targets to
authenticate each other by using a secret code or password.
The figure illustrates the handshake steps that occur between an initiator and a
target:
1. Initiates a login to the target
2. CHAP challenge sent to initiator
VM
VM
3. Takes shared secret and calculates value using a one-way hash function
Hypervisor
4. Returns hash value to the target
Compute System
5. Computes the expected hash value from the shared secret and compares the value
received from initiator
iSCSI Storage System
6. If value matches, authentication is acknowledged
Initiator
Target
Notes
CHAP secrets are random secrets of 12 to 128 characters. The secret is never
exchanged directly over the communication channel. It is rather, a one-way hash
function that converts it into a hash value, which is then exchanged.
A hash function, using the MD5 algorithm, transforms data in such a way that the
result is unique and cannot be changed back to its original form. If the initiator
requires reverse CHAP authentication, the initiator authenticates the target by
using the same procedure. The CHAP secret must be configured on the initiator
and the target. A CHAP entry, which is composed of the name of a node and the
secret associated with the node, is maintained by the target and the initiator.
The same steps are execute run in a two-way CHAP authentication scenario.After
these steps are completed, the initiator authenticates the target. If both the
authentication steps succeed, then data access is enabled. CHAP is often used
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 715
Security Controls Lesson
because it is a simple protocol to implement and can be implemented across
various disparate systems.
Information Storage and Management (ISM) v4
Page 716
© Copyright 2019 Dell Inc.
Security Controls Lesson
Role-based Access Control

An approach to restrict access to authorized users based on their respective
roles
 Only those privileges are assigned to a role that are required to perform
tasks associated with that role

Separation of duties ensures that no single individual can both specify an action
and carry it out
Notes
Role-based access control (RBAC) is an approach to restricting access to
authorized users based on their respective roles. A role may represent a job
function, for example, a storage administrator. Minimum privileges are assigned to
a role that is required to perform the tasks associated with that role.
It is advisable to consider administrative controls, such as separation of duties,
when defining data center security procedures. Clear separation of duties ensures
that no single individual can both specify an action and carry it out. For example,
the person who authorizes the creation of administrative accounts should not be
the person who uses those accounts.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 717
Security Controls Lesson
Firewall and Demilitarized Zone
Definition: Firewall
A security control designed to monitor the incoming and the outgoing
network traffic and compare them to a set of filtering rules.

Firewall security rules may use various filtering parameters such as source
address, destination address, port numbers, and protocols. The effectiveness of
a firewall depends on how robustly and extensively the security rules are
defined.

Firewalls can be deployed at:
 Network level
 Compute level
 Hypervisor level

Uses various parameters for traffic filtering
Definition: Demilitarized Zone
A control to secure internal assets while enabling Internet-based
access to selected resources.
Notes
A network-level firewall is typically used as first line of defense for restricting certain
type of traffic from coming in and going out from a network. This type of firewall is
typically deployed at the entry point of an organization’s network.
At the compute system-level, a firewall application is installed as second line of
defense in a defense-in-depth strategy. This type of firewall provides protection
only to the compute system on which it is installed.
Information Storage and Management (ISM) v4
Page 718
© Copyright 2019 Dell Inc.
Security Controls Lesson
In a virtualized environment, there is an added complexity of virtual machines
running on a smaller number of compute systems. When virtual machines on the
same hypervisor communicate with each other over a virtual switch, a networklevel firewall cannot filter this traffic. In such situations, a virtual firewall can be used
to filter virtual machine traffic.
To reduce the vulnerability and protect the internal resources and applications, the
compute systems or virtual machines that require the Internet access are placed in
a demilitarized zone.
In a demilitarized zone environment, servers that need Internet access are placed
between two sets of firewalls. The servers in the demilitarized zone may or may not
be allowed to communicate with internal resources. Application-specific ports such
as those designated for HTTP or FTP traffic are allowed through the firewall to the
demilitarized zone servers. However, no Internet-based traffic is allowed to go
through the second set of firewalls and gain access to the internal network.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 719
Security Controls Lesson
Intrusion Detection and Prevention System
Definition: Intrusion Detection and Prevention System (IDPS)
A security tool that automates the process of detecting and preventing
events that can compromise the confidentiality, integrity, or availability
of IT resources.

Signature-based detection technique:
 Scans for signatures to detect an intrusion
 Effective only for known threats

Anomaly-based detection technique:
 Scans and analyzes events to detect if they are statistically different from
normal events
 Has the ability to detect various events
Notes
Intrusion detection is the process of detecting events that can compromise the
confidentiality, integrity, or availability of IT resources.
An intrusion detection system (IDS) is a security tool that automates the detection
process. An IDS generates alerts, in case anomalous activity is detected. An
intrusion prevention system (IPS) is a tool that has the capability to stop the events
after they have been detected by the IDS. These two controls usually work together
and are generally referred to as intrusion detection and prevention system (IDPS).
The key techniques used by an IDPS to identify intrusion in the environment are
signature-based and anomaly-based detection.
In the anomaly-based detection technique, the IDPS scans and analyzes events to
determine whether they are statistically different from events normally occurring in
the system. This technique can detect various events such as multiple login
failures, excessive process failure, excessive network bandwidth consumed by an
Information Storage and Management (ISM) v4
Page 720
© Copyright 2019 Dell Inc.
Security Controls Lesson
activity, or an unusual number of emails sent by a user, which could signify an
attack is taking place.
The IDPS can be deployed at the compute system, network, or hypervisor levels.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 721
Security Controls Lesson
Virtual Private Network

Extends a user’s private network across a public network
 Enables to apply internal network’s security and management policies over
the VPN connection

Two methods to establish a VPN connection:
 Remote access VPN connection
o Remote client initiates a remote VPN connection request
o VPN server authenticates and grants access to organization’s network
 Site-to-site VPN connection
o Remote site initiates a site-to-site VPN connection
o VPN server authenticates and grants access to organization’s network
Notes
In the storage environment, a virtual private network (VPN) can be used to provide
a user, a secure connection to the storage resources. VPN is also used to provide
secure site-to-site connection between a primary site and a DR site when
performing remote replication. VPN can also be used to provide secure site-to-site
connection between an organization’s data center and cloud.
A virtual private network extends an organization’s private network across a public
network such as Internet. VPN establishes a point-to-point connection between two
networks over which encrypted data is transferred. VPN enables organizations to
apply the same security and management policies to the data transferred over the
VPN connection as applied to the data transferred over the organization’s internal
network. When establishing a VPN connection, a user is authenticated before the
security and management policies are applied.
There are two methods in which a VPN connection can be established:

Remote access VPN connection

Site-to-site VPN connection
Information Storage and Management (ISM) v4
Page 722
© Copyright 2019 Dell Inc.
Security Controls Lesson
In a remote access VPN connection, a remote client (typically client software
installed on the user’s compute system) initiates a remote VPN connection request.
A VPN server authenticates and provides the user access to the network. This
method can be used by administrators to establish a secure connection to data
center and carry out management operations.
In a site-to-site VPN connection, the remote site initiates a site-to-site VPN
connection. The VPN server authenticates and provides access to internal network.
One typical usage scenario for this method is when deploying a remote replication
or connecting the cloud.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 723
Security Controls Lesson
Malware Protection Software

Detects, prevents, and removes malware programs

Common malware detection techniques:
 Signature-based detection
 Heuristics detection

Protects OS against attacks that modify sensitive areas
 Disallows unauthorized modification of sensitive areas
Notes
Malware protection software is typically installed on a compute system or on a
mobile device to provide protection for the operating system and applications. The
malware protection software detects, prevents, and removes malware and
malicious programs such as viruses, worms, Trojan horses, key loggers, and
spyware. Malware protection software uses various techniques to detect malware.
One of the most common techniques that is used is signature-based detection. In
this technique, the malware protection software scans the files to identify a
malware signature. A signature is a specific bit pattern in a file. These signatures
are cataloged by malware protection software vendors and are made available to
users as updates. The malware protection software must be configured to regularly
update these signatures to provide protection against new malware programs.
Another technique, called heuristics, can be used to detect malware by examining
suspicious characteristics of files. For example, malware protection software may
scan a file to determine the presence of rare instructions or code. Malware
protection software may also identify malware by examining the behavior of
programs. For example, malware protection software may observe program
execution to identify inappropriate behavior such as keystroke capture.
Malware protection software can also be used to protect operating system against
attacks. A common type of attack that is carried out on operating systems is by
modifying its sensitive areas, such as registry keys or configuration files, with the
intention of causing the application to function incorrectly or to fail. This can be
prevented by disallowing the unauthorized modification of sensitive areas by
Information Storage and Management (ISM) v4
Page 724
© Copyright 2019 Dell Inc.
Security Controls Lesson
adjusting operating system configuration settings or through a malware protection
software. In this case, when a modification is attempted, the operating system or
the malware protection software challenges the administrator for authorization.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 725
Security Controls Lesson
Data Encryption
Definition: Data Encryption
A cryptographic technique in which data is encoded and made
indecipherable to eavesdroppers or hackers.

Enables securing data in-flight and at-rest

Provides protection from threats, such as data tampering, media theft, and
sniffing attacks

Data encryption control can be deployed at compute, network, and storage

Data should be encrypted as close to its origin as possible
Notes
Data encryption is one of the most important controls for securing data in-flight and
at-rest. Data in-flight refers to data that is being transferred over a network and
data at-rest refers to data that is stored on a storage medium. Data encryption
provides protection from threats such as tampering with data which violates data
integrity, media theft which compromises data availability, and confidentiality and
sniffing attacks which compromise confidentiality.
Data should be encrypted as close to its origin as possible. If it is not possible to
perform encryption on the compute system, an encryption appliance can be used
for encrypting data at the point of entry into the storage network. Encryption
devices can be implemented on the fabric to encrypt data between the compute
system and the storage media. These controls can protect both the data at-rest on
the destination device and data in-transit. Encryption can also be deployed at the
storage-level, which can encrypt data-at-rest.
Another way to encrypt network traffic is to use cryptographic protocols such as
Transport Layer Security (TLS) which is a successor to Secure Socket Layer
(SSL). These are application layer protocols and provide an encrypted connection
for client-server communication. These protocols are designed to prevent
Information Storage and Management (ISM) v4
Page 726
© Copyright 2019 Dell Inc.
Security Controls Lesson
eavesdropping and tampering of data on the connection over which it is being
transmitted.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 727
Security Controls Lesson
Data Shredding
Definition: Data Shredding
A process of deleting data or residual representation (sometimes
called remanence) of data and making it unrecoverable.

Techniques for shredding data stored on tapes:
 Overwriting tapes with invalid data
 Degaussing media
 Destroying media

Techniques for shredding data stored on disks and flash drives:
 Shredding algorithms

Shred all copies of data including backup and replicas
Notes
Typically, when data is deleted, it is not made unrecoverable from the storage and
an attacker may use specialized tools to recover it. The threat of unauthorized data
recovery is greater when an organization discards the failed storage media such as
disk drive, solid state drive, or tape. After the organization discards the media, an
attacker may gain access to these media and may recover the data by using
specialized tools.
Organizations can deploy data shredding controls in their storage infrastructure to
protect from loss of confidentiality of their data. Data may be stored on disks or on
tapes. Techniques to shred data stored on tape include overwriting it with invalid
data, degaussing the media (a process of decreasing or eliminating the magnetic
field), and physically destroying the media. Data stored on disk or flash drives can
be shredded by using algorithms that overwrite the disks several times with invalid
data.
Organizations may create multiple copies (backups and replicas) of their data and
store at multiple locations as part of business continuity and disaster recovery
Information Storage and Management (ISM) v4
Page 728
© Copyright 2019 Dell Inc.
Security Controls Lesson
strategy. Therefore, organizations must deploy data shredding controls at all
location to ensure that all the copies are shred.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 729
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This section highlights technologies that are relevant to the topics covered in this
module.
This lesson covers the following topics:

RSA SecurID

RSA Security Analytics

RSA Adaptive Authentication

RSA Archer Suite

Dell Change Auditor

Dell InTrust

VMware Airwatch

VMware AppDefense
Information Storage and Management (ISM) v4
Page 730
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts in Practice
Concepts in Practice
RSA SecurID
A two-factor authentication provides an added layer of security to ensure that only
valid users have access to systems and data. RSA SecurID is based on something
a user knows (a password or PIN) and something a user has (an authenticator
device). It provides a much more reliable level of user authentication than reusable
passwords. It generates a new, one-time token code at pre-defined intervals,
making it difficult for anyone other than the genuine user to input the correct token
code at any given time. To access their resources, users combine their secret
Personal Identification Number (PIN) with the token code that is displayed on their
SecurID authenticator device display at that given time. The result is a unique, onetime password used to assure a user’s identity.
RSA Security Analytics
Helps security analysts detect and investigate threats often missed by other
security tools. Security Analytics provides converged network security monitoring
and centralized security information and event management (SIEM). Security
Analytics combines big data security collection, management, and analytics; full
network and log-based visibility; and automated threat intelligence – enabling
security analysts to better detect, investigate, and understand threats they often
could not easily see or understand before. It provides a single platform for
capturing and analyzing large amounts of network, log, and other data. It also
accelerates security investigations by enabling analysts to pivot through terabytes
of metadata, log data, and recreated network sessions. It archives and analyzes
long-term security data through a distributed computing architecture and provides
built-in compliance reports covering a multitude of regulatory regimes.
RSA Adaptive Authentication
A comprehensive authentication and fraud detection platform. Adaptive
Authentication is designed to measure the risk associated with a user’s login and
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 731
Concepts in Practice Lesson
post-login activities by evaluating a variety of risk indicators. Using a risk and rulesbased approach, the system then requires additional identity assurance, such as
out-of-band authentication, for scenarios that are at high risk and violate a policy.
This methodology provides transparent authentication for organizations that want to
protect users accessing websites and online portals, mobile applications and
browsers, Automated Teller Machines (ATMs), Secure Sockets Layer (SSL), virtual
private network (VPN) applications, web access management (WAM) applications,
and application delivery solutions.
RSA Archer Suite
Allows an organization to build an efficient, collaborative enterprise governance,
risk and compliance program across IT, finance, operations and legal domains.
With RSA Archer Suite, an organization can manage risks, demonstrate
compliance, automate business processes, and gain visibility into corporate risk
and security controls. RSA delivers several core enterprise governance, risk, and
compliance solutions, with the integrated risk management feature of RSA Archer
Platform. Business users can quickly implement risk management processes
leading to improved risk management maturity, more informed decision-making,
and enhanced business performance. It also supports users with the freedom to
tailor the solutions and integrate with multiple data sources through code-free
configuration.
RSA Archer platform is an advanced security management system that provides a
single point of visibility and coordination for physical, virtual, and cloud assets. Its
three layers—controls enforcement, controls management, and security
management—work together to provide a single view of information, infrastructure,
and identities across physical and virtual environments.
Dell Change Auditor
Helps customers to audit, alert, protect and reports user activity and configuration
and application changes against Active Directory and Windows applications. The
software has role-based access, enabling auditors to have access to only the
information they need to quickly perform their job. Change Auditor provides visibility
into enterprise-wide activities from one central console, enabling customers to see
how data is being handled.
Information Storage and Management (ISM) v4
Page 732
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Dell InTrust
An IT data analytics solution that provides the organizations the power to search
and analyze vast amounts of data in one place. It provides real-time insights into
user activity across security, compliance, and operational teams. It helps the
administrators to troubleshoot the issues by conducting security investigations
regardless of how and where the data is stored. It helps the compliance officers to
produce reports validating the compliance across multiple systems. This web
interface quickly provides information on who accessed the data, how was it
obtained and how the data was used. This helps the administrators and security
teams to discover the suspicious event trends.
VMware Airwatch
Enables organizations to address the challenges associated with mobility by
providing a simplified, efficient way to view and manage all devices from the central
administration console. This solution enables to enroll devices in an enterprise
environment, configure and update device settings over-the-air, and secure mobile
devices. AirWatch enables to manage devices including Android™, Apple® iOS,
BlackBerry®, Mac® OS, Symbian® and Windows® devices from a single
administration console. AirWatch enables to gain visibility into the devices
connecting to your enterprise network, content and resources.
Benefits offered by the VMware AirWatch are:

Manage different types of devices from a single console

Allow employees to easily enroll their devices

Enable secure access to corporate resources

Integrate with existing enterprise infrastructure

Support employee, corporate-owned and shared devices

Gain visibility across mobile device deployment
VMware AppDefense
It has an authoritative understanding of how data center endpoints are meant to
behave and provides endpoint security to protect applications running in virtualized
environments. AppDefense understands application's intended state and behavior.
It monitors the changes of intended state that indicate a probable threat.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 733
Concepts in Practice Lesson
App defense ensures security in a data center environment by:

Supports integration with third parties: The platform such as RSA NetWitness
Suite leverages it for deeper application context within an enterprise’s virtual
data center, response automation/orchestration, and visibility into application
attacks.

Secures modern application: Security of modern application is guaranteed
through AppDefense by protecting the network and data center endpoints and
also by encrypting the enterprise data at rest.

Provide automatic response: Uses vSphere and VMware NSX Data Center to
automate the correct response. It automatically blocks process communication,
snapshot an endpoint for forensic analysis, and suspend or shut down the
endpoint.
Information Storage and Management (ISM) v4
Page 734
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
1. How can you manage vulnerabilities in a modern data center?
A. Installing security controls
B. Maximizing the attack surface
C. Minimizing work factor
D. Avoid patch updates regularly
2. What is the technique used for data shredding?
A. Degaussing media
B. Masking
C. Backup
D. Hardening
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 735
Summary
Summary
Information Storage and Management (ISM) v4
Page 736
© Copyright 2019 Dell Inc.
Storage Infrastructure Management
Introduction
This module focuses on the key functions and processes of the storage
infrastructure management.
Upon completing this module, you will be able to:
 Describe storage infrastructure management and its functions
 Describe key storage infrastructure management processes
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 737
Introduction to Storage Infrastructure Management Lesson
Introduction to Storage Infrastructure Management
Lesson
Introduction
This lesson covers the key characteristics of platform-centric storage infrastructure
management and the key functions of storage infrastructure management.
This lesson covers the following topics:

List key characteristics of platform-centric storage infrastructure management

Identify key functions of storage infrastructure management
Information Storage and Management (ISM) v4
Page 738
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
Introduction to Storage Infrastructure Management
What is Storage Infrastructure Management?
Definition: Storage Infrastructure Management
All the storage infrastructure-related functions that are necessary for
the management of the infrastructure components and services, and
for the maintenance of data throughout its lifecycle.

Aligns storage operations and services to an organization’s strategic business
goal and service level requirements

Ensures that the storage infrastructure is operated optimally by using as few
resources as needed

Ensures better utilization of existing infrastructure components
Notes
The key storage infrastructure components are compute systems, storage systems,
and storage area networks (SANs). These components could be physical or virtual
and are used to provide services to the users. The storage infrastructure
management includes all the storage infrastructure-related functions that are
necessary for the management of the infrastructure components and services, and
for the maintenance of data throughout its lifecycle. These functions help IT
organizations to align their storage operations and services to their strategic
business goal and service level requirements. They ensure that the storage
infrastructure is operated optimally by using as few resources as needed. They
also ensure better utilization of existing components, thereby limiting the need for
excessive ongoing investment on infrastructure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 739
Introduction to Storage Infrastructure Management Lesson
As organizations are driving their IT infrastructure to support modern data center
applications, the storage infrastructure management is also transformed to meet
the application requirements. Management functions are optimized to help an
organization to become a social networking, mobility, big data, or cloud service
provider. This module describes the storage infrastructure management from a
service provider’s perspective.
Information Storage and Management (ISM) v4
Page 740
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
Key Characteristics of Platform-centric Management
Modern data center management functions are different in many ways from the
traditional management and have the following set of distinctive characteristics:

Service-focused approach

Software-defined infrastructure-aware

End-to-end visibility

Orchestrated operations
Notes
Traditionally, storage infrastructure management is component specific. The
management tools only enable monitoring and management of specific
components(s). This may cause management complexity and system
interoperability issues in a large environment that includes many multi-vendor
components residing in world-wide locations. In addition, traditional management
operations such as provisioning LUNs and zoning are mostly manual. The
provisioning tasks often take days to weeks to complete, due to rigid resource
acquisition process and long approval cycle.
Further, the traditional management processes and tools may not support a service
oriented infrastructure, especially if the requirement is to provide cloud services.
They usually lack the ability to execute management operations in agile manner,
respond to adverse events quickly, coordinate the functions of distributed
infrastructure components, and meet sustained service levels. This component
specific, extremely manual, time consuming, and overly complex management is
simply not appropriate for modern data center infrastructure.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 741
Introduction to Storage Infrastructure Management Lesson
Service-focused Approach
Storage infrastructure management is linked to service requirements and service
level agreement (SLA)
Management functions linked to service requirements and the SLA:

Determine optimal amount of storage space needed in a storage pool to meet
the capacity requirements of services

Create a disaster recovery plan to meet the recovery time objective (RTO) of
services

Ensure that the management processes, management software, and staffing
are appropriate to provide services

Return services to the users within agreed time period in the event of a service
failure

Validate changes to the storage infrastructure for creating or modifying a
service
Notes
The storage infrastructure management in a modern data center has a servicebased focus. It is linked to the service requirements and service level agreement
(SLA).
Service requirements cover the services to be created/upgraded, service features,
service levels, and infrastructure components that constitute a service. An SLA is a
formalized contract document that describes service level targets, service support
guarantee, service location, and the responsibilities of the service provider and the
user. These parameters of a service determine how the storage infrastructure will
be managed.
Information Storage and Management (ISM) v4
Page 742
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
Software-Defined Infrastructure-aware
In a platform-centric environment, more value is given to the software-defined
infrastructure management over the traditional physical component-specific
management, including:

Software-defined infrastructure management is more valued over hardwarespecific management

Management functions move to external software controller

Many common, repeatable, hardware-specific management tasks are
automated

Management is focused on strategic, value-driven activities

Management operations become independent of underlying hardware
Notes
Management functions are increasingly becoming decoupled from the physical
infrastructure and moving to external software controller. As a result of this shift,
the infrastructure components are managed through the software controller. The
controller usually has a native management tool for configuring components and
creating services. Administrators may also use independent management tools for
managing the storage infrastructure. Management tools interact with the controller
commonly through the application programming interfaces (APIs).
Management through a software controller has changed the way a traditional
storage infrastructure is operated. The software controller automates and abstracts
many common, repeatable, and physical component-specific tasks, thereby
reducing the operational complexity. This allows the administrators to focus on
strategic, value-driven activities such as aligning services with the business goal,
improving resource utilization, and ensuring SLA compliance.
Further, the software controller helps in centralizing the management operations.
For example, an administrator may set configuration settings related to automated
storage tiering, thin provisioning, backup, or replication from the management
console. Thereafter, these settings are automatically and uniformly applied across
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 743
Introduction to Storage Infrastructure Management Lesson
all the managed components that may be distributed across wide locations. These
components may also be proprietary or commodity hardware manufactured by
different vendors. But, the software controller ensures that the management
operations are independent of the underlying hardware.
Information Storage and Management (ISM) v4
Page 744
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
End-to-end Visibility

Management in modern data center environments provides end-to-end visibility
into the storage infrastructure components and deployed services.
 Provides information on the configuration, connectivity, capacity,
performance, and interrelationships of all components centrally
 Helps in consolidating reports, correlating issues, and tracking movement of
data and services across infrastructure

End-to-end visibility of a storage infrastructure is provided by specialized
monitoring tools
Notes
The end-to-end visibility of the storage infrastructure enables comprehensive and
centralized management. The administrators can view the configuration,
connectivity, capacity, performance, and interrelationships of all infrastructure
components centrally. Further, it helps in consolidating reports of capacity
utilization, correlating issues in multiple components, and tracking the movement of
data and services across the infrastructure.
Depending on the size of the storage infrastructure and the number of services
involved, the administrators may have to monitor information about hundreds or
thousands of components located in multiple data centers. In addition, the
configuration, connectivity, and interrelationships of components change as the
storage infrastructure grows, applications scale, and services are updated.
Organizations typically deploy specialized monitoring tools that provide end-to-end
visibility of a storage infrastructure on a digital dashboard. In addition, they are
capable of reporting relevant information in a rapidly changing and varying
workload environment.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 745
Introduction to Storage Infrastructure Management Lesson
Orchestrated Operations
Definition: Orchestration
Automated arrangement, coordination, and management of various
system or component functions in a storage infrastructure.

Management operations are orchestrated as much as possible to provide
business agility
 Reduces time to provide and manage a service
 Reduces risk of manual errors and administration cost

An orchestrator programmatically integrates and sequences inter-related
component functions into workflows
 Triggers an appropriate workflow upon receiving a request
Notes
Orchestration refers to the automated arrangement, coordination, and management
of various system or component functions in a storage infrastructure. Orchestration,
unlike an automated activity, is not associated with a specific infrastructure
component. Instead, it may span multiple components, located in different locations
depending on the size of a storage infrastructure. In order to sustain in a modern
data center environment, the storage infrastructure management must rely on
orchestration.
Management operations should be orchestrated as much as possible to provide
business agility. Orchestration reduces the time to configure, update, and integrate
a group of infrastructure components that are required to provide and manage a
service. By automating the coordination of component functions, it also reduces the
risk of manual errors and the administration cost.
A purpose-built software, called orchestrator, is commonly used for orchestrating
component functions in a storage infrastructure. The orchestrator provides a library
Information Storage and Management (ISM) v4
Page 746
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
of predefined workflows for executing various management operations. Workflow
refers to a series of inter-related component functions that are programmatically
integrated and sequenced to accomplish a desired outcome. The orchestrator also
provides an interface for administrators or architects to define and customize
workflows. It triggers an appropriate workflow upon receiving a service provisioning
or management request. Thereafter, it interacts with the components as per the
workflow to coordinate and sequence the execution of functions by these
components.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 747
Introduction to Storage Infrastructure Management Lesson
Orchestration Example
The example illustrates an orchestrated operation that creates a block volume for a
compute system.
Orchestrator
Administrator
Storage
Available
in Pool?
Get Capacity and
ConfigurationDetails
Create
Volume
No
Update
Portal
(Wait for
Approval)
Provision More Storage to
StoragePool
Yes
Yes
Management
Portal
Storage
available in
pool?
Update Portal
(Operation
in Progress)
Start
Perform Zoningon SAN
Switch
Update Portal (Operation
Completed)
No
End
SDS Controller
Create LUN in Storage
System
Mask LUN in Storage
System
Create Logical Volume on
ComputeSystem
Update Portal (Operation
Failed)
Perform Bus Rescan on
ComputeSystem
End
Storage Infrastructure
V
V
AP
AP
O
O
VMM
VMM
Hypervisor Kernel
FC Switch
Storage
System
ComputeSystem
Interaction
Notes
In this example, an administrator logs on to the management portal and initiates the
volume creation operation from the portal. The operation request is routed to the
orchestrator which triggers a workflow, as shown on the slide, to fulfill this request.
The workflow programmatically integrates and sequences the required compute,
storage, and network component functions to create the block volume.
The orchestrator interacts with the software-define storage (SDS) controller to let
the controller to carry out the operation according to the workflow. The SDS
controller interacts with the infrastructure components to enable the execution of
component functions such as zoning, LUN creation, and bus rescan. Through the
workflow, the management portal receives the response on the outcome of the
operation.
Information Storage and Management (ISM) v4
Page 748
© Copyright 2019 Dell Inc.
Introduction to Storage Infrastructure Management Lesson
Storage Infrastructure Management Functions
Storage infrastructure management performs two key functions: infrastructure
discovery and operations management.
Definition: Discovery
A management function that creates an inventory of infrastructure
components and provides information about the components
including their configuration, connectivity, functions, performance,
capacity, availability, utilization, and physical-to-virtual dependencies.
Infrastructure Discovery

Discovery provides visibility into each infrastructure component
 Discovered information helps in monitoring and management

Discovery tool interacts and collects information from components

Discovery is typically scheduled to occur periodically
 May also be initiated by an administrator or triggered by an orchestrator
Operations Management

Involves on-going management activities to maintain storage infrastructure and
deployed services

Key processes that support operations management activities are:
 Monitoring
 Configuration management
 Change management
 Capacity management
 Performance management
 Availability management
 Incident management
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 749
Introduction to Storage Infrastructure Management Lesson
 Problem management
 Security management
Notes
Infrastructure discovery provides the visibility needed to monitor and manage the
infrastructure components. Discovery is performed using a specialized tool that
commonly interacts with infrastructure components commonly through the native
APIs of these components. Through the interaction, it collects information from the
infrastructure components.
A discovery tool may be integrated with the software-defined infrastructure
controller, bundled with a management software, or an independent software that
passes discovered information to a management software. Discovery is typically
scheduled by setting an interval for its periodic occurrence. Discovery may also be
initiated by an administrator or be triggered by an orchestrator when a change
occurs in the storage infrastructure.
Operations management involves several management processes. The slide lists
the key processes that support operations management activities. The subsequent
lessons will describe these processes. Ideally, operations management should be
automated to ensure the operational agility. Management tools are usually capable
of automating many management operations. These automated operations are
described along with the management processes. Further, the automated
operations of management tools can also be logically integrated and sequenced
through orchestration.
Information Storage and Management (ISM) v4
Page 750
© Copyright 2019 Dell Inc.
Operations Management
Operations Management
Introduction
This lesson covers monitoring, alerting, and reporting in a storage environment.
This lesson also covers configuration management, change management, capacity
management, performance management, availability management, incident
management, problem management, and security management.
This lesson covers the following topics:

Explain monitoring, alerting, and reporting

Describe configuration management and change management

Explain capacity management and performance management

Discuss availability management

Explore incident management and problem management

Emphasize the importance of security management
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 751
Operations Management
Operations Management
Introduction to Monitoring

Monitoring provides visibility into the storage infrastructure and forms the basis
for performing management operations

It helps to
– Track the performance and availability status of components and services
– Measure the utilization and consumption of resources by services
– Track events impacting availability and performance of components and
services
– Generate reports and triggering alerts
– Track environment parameters (HVAC)
Notes
Monitoring forms the basis for performing management operations. Monitoring
provides the performance and availability status of various infrastructure
components and services. It also helps to measure the utilization and consumption
of various storage infrastructure resources by the services. This measurement
facilitates the metering of services, capacity planning, forecasting, and optimal use
of these resources. Monitoring events in the storage infrastructure, such as a
change in the performance or availability state of a component or a service, may be
used to trigger automated routines or recovery procedures.
Such procedures can reduce downtime due to known infrastructure errors and the
level of manual intervention needed to recover from them. Further, monitoring
helps in generating reports for service usage and trends. It also helps to trigger
alerts when thresholds are reached, security policies are violated, and service
performance deviates from SLA. Alerting and reporting are detailed later in this
module. Additionally, monitoring of the data center environment parameters such
Information Storage and Management (ISM) v4
Page 752
© Copyright 2019 Dell Inc.
Operations Management
as heating, ventilating, and air-conditioning (HVAC) helps in tracking any anomaly
from their normal status.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 753
Operations Management
Monitoring Parameters
Storage infrastructure is primarily monitored for:

Configuration

Availability

Capacity

Performance

Security
Information Storage and Management (ISM) v4
Page 754
© Copyright 2019 Dell Inc.
Operations Management
Monitoring Configuration
Tracks the configuration changes in a storage infrastructure and their compliance
to the configuration policies
WWN 10:00:00:90:FA:18:0D:CF
WWN 50:06:01:6F:08:60:1E:BD
Zone esx161_vnx_152_1
VM
VM
Hypervisor
VM
VM
Hypervisor
FC Switch
VM
VM
Hypervisor
Compute Systems
Storage Systems
The table lists configuration changes in the storage infrastructure shown in the
image.
Changed At
Description
Device
Compliance
Breach
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 755
Operations Management
2019/01/07
@ 13:34:23
The member
10000090FA180DCF
has been added to the
zone
esx161_vnx_152_1
100000051E023364
No
2019/01/07
@ 13:34:23
The member
5006016F08601EBD
has been added to the
zone
esx161_vnx_152_1
100000051E023364
No
2019/01/07
@ 13:34:23
A new zone
esx161_vnx_152_1 has
been added to the fabric
100000051E023364
100000051E023364
No
Notes
Monitoring configuration involves tracking configuration changes and deployment of
storage infrastructure components and services. It also detects configuration
errors, non-compliance with configuration policies, and unauthorized configuration
changes.
Configuration changes are captured and reported by a monitoring tool in real-time.
In the environment shown by the illustration, a new zone was created to enable a
compute system to access LUNs from one of the storage systems. The changes
were made on the FC switch (device).
Information Storage and Management (ISM) v4
Page 756
© Copyright 2019 Dell Inc.
Operations Management
Monitoring Availability
Identifies the failure of any component or process that may lead to service
unavailability or degraded performance.
The figure illustrates an example of monitoring the availability of storage
infrastructure components.
VM
VM
APP
APP
OS
OS
No redundancy due to switch
SW1 failure
Hypervisor
SW1
VM
VM
APP
APP
OS
OS
Hypervisor
VM
VM
APP
APP
OS
OS
SW2
Storage Systems
Hypervisor
Compute Systems
Notes
Availability refers to the ability of a component or a service to perform its desired
function during its specified time of operation. Monitoring availability of hardware
components (for example, a port, an HBA, or a storage controller) or software
component (for example, a database instance or an orchestration software)
involves checking their availability status by reviewing the alerts generated from the
system. For example, a port failure might result in a chain of availability alerts.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 757
Operations Management
A storage infrastructure commonly uses redundant components to avoid a single
point of failure. Failure of a component might cause an outage that affects service
availability, or it might cause performance degradation even though availability is
not compromised. Continuous monitoring for expected availability of each
component and reporting any deviation help the administrator to identify failing
services and plan corrective action to maintain SLA requirements.
The figure illustrates an example of monitoring the availability of storage
infrastructure components, including:

A storage infrastructure includes three compute systems (H1, H2, and H3) that
are running hypervisors

All the compute systems are configured with two FC HBAs, each connected to
the production storage system through two FC switches, SW1 and SW2. All the
compute systems share two storage ports on the storage system.

Multipathing software has also been installed on hypervisor running on all the
three compute systems. If one of the switches, SW1 fails, the multipathing
software initiates a path failover, and all the compute systems continue to
access data through the other switch, SW2.

Due to absence of redundant switch, a second switch failure could result in
unavailability of the storage system. Monitoring for availability enables detecting
the switch failure and helps administrator to take corrective action before
another failure occurs. In most cases, the administrator receives symptom alerts
for a failing component and can initiate actions before the component fails.
Information Storage and Management (ISM) v4
Page 758
© Copyright 2019 Dell Inc.
Operations Management
Monitoring Capacity
Tracks the amount of storage infrastructure resources used and free.
The figure provides an example that illustrates the importance of monitoring NAS
file system capacity.
Notification: File system is 80% Full
File System Expanded
NAS
NAS
Notification: File system is 66% Full
Free
Capacity
Free
Capacity
Free
Capacity
Free
Capacity
Used
Capacity
Used
Capacity
NAS File System
LUNs
Used
Capacity
Used
Capacity
NAS File
System
NAS File System
NAS File
System
NAS File
System
NAS File
System
LUNs
Time
Notes
Capacity refers to the total amount of storage infrastructure resources available.
Inadequate capacity leads to degraded performance or even service unavailability.
Monitoring capacity involves examining the amount of storage infrastructure
resources used and usable such as the free space available on a file system or a
storage pool, the numbers of ports available on a switch, or the utilization of
allocated storage space to a service.
Monitoring capacity helps an administrator to ensure uninterrupted data availability
and scalability by averting outages before they occur. For example, if 90 percent of
the ports are utilized in a particular SAN fabric, this could indicate that a new switch
might be required if more compute and storage systems need to be attached to the
same fabric. Monitoring usually leverages analytical tools to perform capacity trend
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 759
Operations Management
analysis. These trends help to understand future resource requirements and
provide an estimation of the time required to deploy them.
The figure provides an example that illustrates the importance of monitoring NAS
file system capacity:

If the file system is full and no space is available for applications to perform
write I/O, it may result in application/service outage

Monitoring tools can be configured to issue a notification when thresholds are
reached on the file system capacity; for example:
 When the file system reaches 66 percent of its capacity, a warning message
is issued, and a critical message is issued when the file system reaches 80
percent of its capacity
 This enables the administrator to take actions to provision additional LUNs
to the NAS and extend the NAS file system before it runs out of capacity

Proactively monitoring the file system can prevent service outages caused due
to lack of file system space
Information Storage and Management (ISM) v4
Page 760
© Copyright 2019 Dell Inc.
Operations Management
Monitoring Performance
Evaluates how efficiently the infrastructure components and services are
performing.
The figure provides an example that illustrates the importance of monitoring
performance on iSCSI storage systems.
VM
H1
VM
APP
APP
OS
OS
Hypervisor
Storage Systems
VM
H2
SW1
VM
APP
APP
OS
OS
Hypervisor
VM
H3
VM
APP
APP
OS
OS
SW2
Hypervisor
100%
New Compute
Systems
VM
VM
APP
APP
OS
OS
Hypervisor
Compute Systems
Port
Utilization
%
H1 + H2 + H3
Notes
Performance monitoring evaluates how efficiently different storage infrastructure
components and services are performing and helps to identify bottlenecks.
Performance monitoring measures and analyzes behavior in terms of response
time, throughput, and I/O wait time. It identifies whether the behavior of
infrastructure components and services meets the acceptable and agreed
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 761
Operations Management
performance level. This helps to identify performance bottlenecks. It also deals with
the utilization of resources, which affects the way resources behave and respond.
For example, if a VM is experiencing 80 percent of processor utilization
continuously, it suggests that the VM may be running out of processing power,
which can lead to degraded performance and slower response time. Similarly, if the
cache and controllers of a storage system is consistently over utilized, it may lead
to performance degradation.
The figure provides an example that illustrates the importance of monitoring
performance on iSCSI storage systems; in this example:

Compute systems H1, H2, and H3 (with two iSCSI HBAs each) are connected
to the storage system through Ethernet switches SW1 and SW2

The three compute systems share the same storage ports on the storage
system to access LUNs

A new compute system running an application with a high work load must be
deployed to share the same storage port as H1, H2, and H3

Monitoring storage port utilization ensures that the new compute system does
not adversely affect the performance of the other compute systems
Utilization of the shared storage port is shown by the solid and dotted lines in the
graph. If the port utilization prior to deploying the new compute system is close to
100 percent, then deploying the new compute system is not recommended
because it might impact the performance of the other compute systems. However,
if the utilization of the port prior to deploying the new compute system is closer to
the dotted line, then there is room to add a new compute system.
Information Storage and Management (ISM) v4
Page 762
© Copyright 2019 Dell Inc.
Operations Management
Monitoring Security
Tracks unauthorized access and configuration changes to the storage
infrastructure and services.
This figure illustrates the importance of monitoring security in a storage system.
Workgroup 2 (WG2)
V
V
AP
AP
O
S
O
S
Hypervisor
V
V
V
V
AP
AP
AP
AP
O
S
O
S
O
S
Hypervisor
SW1
O
S
Hypervisor
WG2
WG1
V
V
AP
AP
O
S
SW2
O
S
Hypervisor
Replication
Command
V
V
V
V
AP
AP
AP
AP
O
S
O
S
O
S
Hypervisor
O
S
Hypervisor
Warning: Attempted replication of WG2 devices
by WG1 user - Access denied
Storage System
Inaccessible
Workgroup 1 (WG1)
Notes
Monitoring a storage infrastructure for security includes tracking unauthorized
access, whether accidental or malicious, and unauthorized configuration changes.
For example, monitoring tracks and reports the initial zoning configuration
performed and all the subsequent changes. Another example of monitoring security
is to track login failures and unauthorized access to switches for performing
administrative changes.
IT organizations typically comply with various information security policies that may
be specific to government regulations, organizational rules, or deployed services.
Monitoring detects all operations and data movement that deviate from predefined
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 763
Operations Management
security policies. Monitoring also detects unavailability of information and services
to authorized users due to security breach. Further, physical security of a storage
infrastructure can also be continuously monitored using badge readers, biometric
scans, or video cameras.
The figure illustrates the importance of monitoring security in a storage system. In
this example:

The storage system is shared between two workgroups, WG1 and WG2

The data of WG1 should not be accessible by WG2 and vice versa

A user from WG1 might try to make a local replica of the data that belongs to
WG2

If this action is not monitored or recorded, it is difficult to track such a violation of
security protocols

Conversely, if this action is monitored, a warning message can be sent to
prompt a corrective action or at least enable discovery as part of regular
auditing operations
Information Storage and Management (ISM) v4
Page 764
© Copyright 2019 Dell Inc.
Operations Management
Alerting
Alerts are system-to-user notifications

Provide information about events or impending threats or issues

Keep administrators informed on the status of components, processes, and
services

Trigger when specific situations or conditions are reached
 Conditions may be defined through monitoring tool
Type of
Alert
Description
Information 
Warning
Fatal
Example
Provide useful information

Creation of zone or LUN

Does not require
administrator intervention

Creation of a new storage pool

Requires administrative
attention

Storage pool is becoming full

Soft media errors
Requires immediate
attention

Storage pool is full

Multiple disk failures in RAID set

Notes
An alert is a system-to-user notification that provides information about events or
impending threats or issues. Alerting of events is an integral part of monitoring.
Alerting keeps administrators informed about the status of various components and
processes – for example, conditions such as failure of power, storage drives,
memory, switches, or availability zone, which can impact the availability of services
and require immediate administrative attention. Other conditions, such as a file
system reaching a capacity threshold, an operation breaching a configuration
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 765
Operations Management
policy, or a soft media error on storage drives, are considered warning signs and
may also require administrative attention.
Monitoring tools enable administrators to define various alerted conditions and
assign different severity levels for these conditions based on the impact of the
conditions. Whenever a condition with a particular severity level occurs, an alert is
sent to the administrator, an orchestrated operation is triggered, or an incident
ticket is opened to initiate a corrective action. Alert classifications can range from
information alerts to fatal alerts. Information alerts provide useful information but do
not require any intervention by the administrator.
The creation of a zone or LUN is an example of an information alert. Warning alerts
require administrative attention so that the alerted condition is contained and does
not affect service availability. For example, if an alert indicates that a storage pool
is approaching a predefined threshold value, the administrator can decide whether
additional storage drives need to be added to the pool. Fatal alerts require
immediate attention because the condition might affect the overall performance or
availability. For example, if multiple disks fail in a RAID set, the administrator must
ensure that it is returned quickly.
As every IT environment is unique, most monitoring systems require initial set-up
and configuration, including defining what types of alerts should be classified as
informational, warning, and fatal. Whenever possible, an organization should limit
the number of truly critical alerts so that important events are not lost amidst
informational messages. Continuous monitoring, with automated alerting, enables
administrators to respond to failures quickly and proactively. Alerting provides
information that helps administrators prioritize their response to events.
Information Storage and Management (ISM) v4
Page 766
© Copyright 2019 Dell Inc.
Operations Management
Reporting

Involves gathering information from various components or processes and
generating reports

Reports are displayed like a digital dashboard
 Provides real time tabular or graphical views of monitored information

Commonly used reports are:
 Capacity planning report
 Configuration and asset management reports
 Chargeback report
 Performance report
 Security breach report
Notes
Like alerting, reporting is also associated with monitoring. Reporting on a storage
infrastructure involves keeping track and gathering information from various
components and processes that are monitored. The gathered information is
compiled to generate reports for trend analysis, capacity planning, chargeback,
performance, and security breaches. Capacity planning reports contain current and
historic information about the utilization of storage, file systems, database
tablespace, ports, etc.
Configuration and asset management reports include details about device
allocation, local or remote replicas, and fabric configuration. This report also lists all
the equipment, with details, such as their purchase date, lease status, and
maintenance records. Chargeback reports contain information about the allocation
or utilization of storage infrastructure resources by various users or user groups.
Performance reports provide current and historical information about the
performance of various storage infrastructure components and services as well as
their compliance with agreed service levels. Security breach reports provide details
on the security violations, duration of breach and its impact.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 767
Operations Management
Reports are commonly displayed like a digital dashboard, which provide real time
tabular or graphical views of gathered information. Dashboard reporting helps
administrators to make instantaneous and informed decisions on resource
procurement, plans for modifications in the existing infrastructure, policy
enforcement, and improvements in management processes.
Information Storage and Management (ISM) v4
Page 768
© Copyright 2019 Dell Inc.
Operations Management
Example – Chargeback Report
The ability to measure storage resource consumption per business unit or user
group and charge them back accordingly.

To perform chargeback, the storage usage data is collected by a billing system
that generates chargeback report for each business unit or user group

The billing system is responsible for accurate measurement of the number of
units of storage used and reports cost/charge for the consumed units
The figure shows the assignment of storage resource as services to two business
units, Payroll_1 and Engineering_1, and presents a sample chargeback report.
Payroll_1 Compute
Systems
50 GB
50 GB
50 GB
50 GB
Production LUN
(RAID 1)
Engineering_1 Compute
Systems
50 GB
50 GB
Remote
Replica
(RAID 5)
Local Replica (RAID
0)
100 GB
100 GB
100 GB
100 GB
100 GB
100 GB
Production Storage System
Remote Storage System
Notes
In this example, each business unit is using a set of compute systems that are
running hypervisor. The VMs hosted on these compute systems are used by the
business units. LUNs are assigned to the hypervisor from the production storage
system. Storage system-based replication technology is used to create both local
and remote replicas. A chargeback report documenting the exact amount of
storage resources used by each business unit is created by a billing system. If the
unit for billing is GB of raw storage, the exact amount of raw space (usable capacity
plus protection provided) configured for each business unit must be reported.
Consider that the Payroll_1 unit has consumed two production LUNs, each 50 GB
in size. Therefore, the storage allocated to the hypervisor is 100 GB (50 + 50). The
allocated storage for local replication is 100 GB and for remote replication is also
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 769
Operations Management
100 GB. From the allocated storage, the raw storage configured for the hypervisor
is determined based on the RAID protection that is used for various storage pools.
If the Payroll_1 production LUNs are RAID 1-protected, the raw space used by the
production volumes is 200 GB.
Assume that the local replicas are on unprotected LUNs, and the remote replicas
are protected with a RAID 5 configuration, then 100 GB of raw space is used by the
local replica and 125 GB by the remote replica. Therefore, the total raw capacity
used by the Payroll_1 unit is 425 GB. The total cost of storage provisioned for
Payroll_1 unit will be $2,125 (assume cost per GB of raw storage is $5). The
Engineering_1 unit also uses two LUNs, but each 100 GB in size. Considering the
same RAID protection and per unit cost, the chargeback for the Engineering_1 unit
will be $3,500.
Information Storage and Management (ISM) v4
Page 770
© Copyright 2019 Dell Inc.
Operations Management
Operations Management Processes

Some of the main processes of operation management include:
– Configuration management
– Change management
– Capacity management
– Performance management
– Availability management
– Incident management
– Problem management
– Security management
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 771
Operations Management
Configuration Management
Goal: Configuration Management
Maintains information about “configuration items (CIs)” that are
required to deliver services.
Key functions:

Discovers and maintains information on CIs in a configuration management
system (CMS)

Updates CMS when new CIs are deployed, or CI attributes change
Examples of CI information:

Attributes of CIs such as CI’s name, manufacturer name, serial number, license
status, version, location, and inventory status

Used and available capacity of CIs

Issues linked to CIs

Inter-relationships among CIs such as service-to-user, storage pool-to-service,
storage system-to-storage pool, and storage system-to-SAN switch
Notes
Configuration management is responsible for maintaining information about
configuration items (CI). CIs are components such as services, process
documents, infrastructure components including hardware and software, people,
and SLAs that need to be managed in order to deliver services. The information
about CIs include their attributes, used and available capacity, history of issues,
and inter-relationships. Examples of CI attribute are the CI’s name, manufacturer
name, serial number, license status, version, description of modification, location,
and inventory status (for example, on order, available, allocated, or retired). The
inter-relationships among CIs in a storage infrastructure commonly include serviceto-user, storage pool-to-service, storage volume-to-storage pool, storage system-
Information Storage and Management (ISM) v4
Page 772
© Copyright 2019 Dell Inc.
Operations Management
to-storage pool, storage system-to-SAN switch, and data center-to geographic
location.
All information about CIs is usually collected and stored by the discovery tools in a
single database or in multiple autonomous databases mapped into a federated
database called a configuration management system (CMS). Discovery tools also
update the CMS when new CIs are deployed or when attributes of CIs change.
CMS provides a consolidated view of CI attributes and relationships, which is used
by other management processes for their operations. For example, CMS helps the
security management process to examine the deployment of a security patch on
VMs, the problem management to resolve a connectivity issue, or the capacity
management to identify the CIs affected on expansion of a storage pool.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 773
Operations Management
Change Management
Goal: Change Management
Standardizes change-related procedures in a storage infrastructure
for prompt handling of all changes with minimal impact on service
quality.
Key function:

Assesses potential risks of all changes to the CIs and makes a decision to
approve/reject the requested changes
 Low risk, routine, and compliant changes may be approved automatically
through an orchestrated approval process
 All other changes are reviewed by the change management team
Notes
With the changing business requirements, the ongoing changes to the CIs become
almost daily task. Relevant changes could range from the introduction of a new
service, to modification of an existing service’s attributes, to retirement of a service;
from replacing a SAN switch, to expansion of a storage pool, to a software
upgrade, and even to a change in process or procedural documentation. Change
management standardizes change-related procedure in a storage infrastructure to
respond to the changing business requirements in an agile way. It oversees all
changes to the CIs to minimize adverse impact of those changes to the business
and the users of services.
Change management typically uses an orchestrated approval process that helps
making decision on changes in an agile manner. Through an orchestration
workflow, the change management receives and processes the requests for
changes. Changes that are at low risk, routine, and compliant to predefined change
policies go through the change management process only once to determine that
they can be exempted from change management review thereafter. After that,
Information Storage and Management (ISM) v4
Page 774
© Copyright 2019 Dell Inc.
Operations Management
these requests are typically treated as service requests and approved
automatically. All other changes are presented for review to the change
management team. The change management team assesses the potential risks of
the changes, prioritizes, and makes a decision on the requested changes.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 775
Operations Management
Capacity Management
Goal: Capacity Management
Ensures that a storage infrastructure is able to meet the required
capacity demands for services in a cost effective and timely manner.
Key functions:

Determines optimal amount of storage needed to meet SLA

Maximizes capacity utilization without impacting service levels

Establishes capacity consumption trends and plans for additional capacity
Examples of capacity management activities:

Adding new nodes to a scale-out NAS cluster or an object-based storage
system

Enforcing capacity quotas for users

Expanding a storage pool and setting a threshold for maximum utilization

Forecasting usage of file system, LUN, and storage pool

Removing unused resources from a service and reassigning those to another
Notes
Capacity management ensures adequate availability of storage infrastructure
resources to provide services and meet SLA requirements. It determines the
optimal amount of storage required to meet the needs of a service regardless of
dynamic resource consumption and seasonal spikes in storage demand. It also
maximizes the utilization of available capacity and minimizes spare and stranded
capacity without compromising the service levels.
Capacity management tools are usually capable of gathering historical information
on storage usage over a specified period of time, establishing trends on capacity
consumption, and performing predictive analysis of future demand. This analysis
Information Storage and Management (ISM) v4
Page 776
© Copyright 2019 Dell Inc.
Operations Management
serves as input to the capacity planning activities and enables the procurement and
provisioning of additional capacity in the most cost effective and least disruptive
manner.
Adding new nodes to a scale-out NAS cluster or an object-based storage system is
an example of capacity management. Addition of nodes increases the overall
processing power, memory, or storage capacity. Enforcing capacity quotas for
users is another example of capacity management. Provisioning a fixed amount of
space for their files restricts users from exceeding the allocated capacity. Other
examples include creating and expanding a storage pool, setting a threshold for the
maximum utilization and amount of oversubscription allowed for each storage pool,
forecasting the usage of file system, LUN, and storage pool, and removing unused
resources from a service for their reassignment to another resource-crunched
service.
Capacity management team uses several methods to maximize the utilization of
capacity. Some of the common methods are over-commitment of processing power
and memory, data deduplication and compression, automated storage tiering, and
use of converged network such as an FCoE SAN.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 777
Operations Management
Capacity Management Example
This example illustrates the expansion of a NAS file system using an orchestrated
workflow. The file system is expanded to meet the capacity requirement of a
compute cluster that accesses the file system.
Administrator
Orchestration
Start
Change Management
Yes
Expand File System to a
Specific Size
Approval
Required?
Review and Approve/Reject Change
Request
Request for Approval
No
Yes
Management Portal
Request
Approved?
Expand File System
SDS Controller
Add Required Capacity to File System
No
Discover and Update CMS
Update Portal (Operation
Rejected)
Configuration Management
Upload CMS
Update Portal (Operation
Completed)
End
End
Interaction
Notes
In the example, an administrator initiates a file system expansion operation from
the management portal. The operation request is transferred to the orchestrator
that triggers a change approval and execution workflow. The orchestrator
determines whether the request for change needs to be reviewed by change
management team. If the request is preapproved, it is exempted from change
management review. If not, the orchestrated workflow ensures that the change
management team reviews and approves/rejects the request.
If the file system expansion request is approved, the orchestrator interacts with the
SDS controller to invoke the expansion. Thereafter, the SDS controller interacts
with the storage infrastructure components to add the required capacity to the file
system. The orchestrated workflow also invokes the discovery operation which
updates the CMS with information on the modified file system size. The
orchestrator responds by sending updates to the management portal appropriately
following completion or rejection of the expansion operation.
Information Storage and Management (ISM) v4
Page 778
© Copyright 2019 Dell Inc.
Operations Management
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 779
Operations Management
Performance Management
Goal: Performance Management
Monitors, measures, analyzes, and improves the performance of
storage infrastructure and services.
Key functions:

Measures and analyzes the response time and throughput of components

Identifies components that are performing below the expected level

Makes configuration changes to optimize performance and address issues
Examples of performance management activities:

Tuning database design, resource allocation to VMs, and multipathing

Adding new ISLs and aggregating links to eliminate bottleneck

Separating sequential and random I/Os to different spindles

Changing storage tiering policy and cache configuration
Notes
Performance management ensures the optimal operational efficiency of all
infrastructure components so that storage services can meet or exceed the
required performance level. Performance-related data such as response time and
throughput of components are collected, analyzed, and reported by specialized
management tools. The performance analysis provides information on whether a
component meets the expected performance levels. These tools also proactively
alert administrators about potential performance issues and may prescribe a
course of action to improve a situation.
Performance management team carries out several activities to address
performance-related issues and improve the performance of the storage
infrastructure components. For example, to optimize the performance levels,
Information Storage and Management (ISM) v4
Page 780
© Copyright 2019 Dell Inc.
Operations Management
activities on the compute system include fine-tuning the volume configuration,
database design or application layout, resource allocation to VMs, workload
balancing, and multipathing configuration. The performance management tasks on
a SAN include implementing new ISLs and aggregating links in a multiswitch fabric
to eliminate performance bottleneck. The storage system-related tasks include
separating sequential and random I/Os to different spindles, selecting an
appropriate RAID type for a storage pool, and changing storage tiering policy and
cache configuration, when the performance management is concerned.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 781
Operations Management
Availability Management
Goal: Availability Management
Ensures that the availability requirements of all the components and
services are consistently met.
Key functions:

Establishes guideline to meet stated availability levels at a justifiable cost

Identifies availability-related issues and areas for improvement

Proposes changes in existing BC solutions or architects new BC solutions
Examples of availability management activities

Deploying redundant, fault tolerant, and hot-swappable components

Deploying compute cluster, fault resilient applications, and multipathing
software

Designing multiple availability zones for automated service failover

Planning and architecting data backup and replication solutions
Notes
Availability management is responsible for establishing a proper guideline based on
the defined availability levels of services. The guideline includes the procedures
and technical features required to meet or exceed both current and future service
availability needs at a justifiable cost. Availability management also identifies all
availability-related issues in a storage infrastructure and areas where availability
must be improved. The availability management team proactively monitors whether
the availability of existing services and components is maintained within acceptable
and agreed levels. The monitoring tools also help administrators to identify the gap
between the required availability and the achieved availability. With this
information, the administrators can quickly identify errors or faults in the
infrastructure components that may cause future service unavailability.
Information Storage and Management (ISM) v4
Page 782
© Copyright 2019 Dell Inc.
Operations Management
Based on the service availability requirements and areas found for improvement,
the availability management team may propose new business continuity (BC)
solutions or changes in the existing BC solutions. For example, when a set of
compute systems is deployed to support a service or any critical business function,
it requires high availability. The availability management team proposes
redundancy at all levels, including components, data, or even site levels. This is
generally accomplished by deploying two or more HBAs per system, multipathing
software, and compute clustering.
The compute systems must be connected to the storage systems using at least two
independent fabrics and switches that have built-in redundancy and hot-swappable
components. The VMs running on these compute systems must be protected from
hardware failure/unavailability through VM failover mechanisms. Deployed
applications should have built-in fault resiliency features. The storage systems
should also have built-in redundancy for various components and should support
local and remote replication. RAID-protected LUNs should be provisioned to the
compute systems using at least two front-end ports. In addition, multiple availability
zones may be created to support fault tolerance at the site level.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 783
Operations Management
Incident Management
Goal: Incident Management
Returns services to users as quickly as possible when unplanned
events, called ‘incidents’, interrupt services or degrade service quality.
Key functions:

Detects and records all incidents in a storage infrastructure

Investigates incidents and provides solutions to resolve the incidents

Documents incident history
The table provides a sample list of incidents that are captured by an incident
management tool.
Severit
y
Event
Summar
y
Device
Priorit
y
Statu
s
Last
Updated
Owne
r
Escalatio
n
Fatal
Pool A
usage is
95%
Storag
e
system
1
None
New
2019/01/0
7
12:38:34
-
No
Fatal
Database
1 is down
DB
server
1
High
WIP
2019/01/0
7
10:11:03
L.
John
Support
Group 2
Warning Port 3
utilization
is 85%
Switch
A
Mediu
m
WIP
2019/01/0
7
09:48:14
P. Kim Support
Group 1
Information Storage and Management (ISM) v4
Page 784
© Copyright 2019 Dell Inc.
Operations Management
Notes
An incident is an unplanned event such as an HBA failure or an application error
that may cause an interruption to services or degrade the service quality. Incident
management is responsible for detecting and recording all incidents in a storage
infrastructure. It investigates the incidents and provides appropriate solutions to
resolve the incidents. It also documents the incident history with details of the
incident symptoms, affected services, components and users, time to resolve the
incident, severity of the incident, description of the error, and the incident resolution
data. The incident history is used as an input for problem management (described
next).
Incidents are commonly detected and logged by incident management tools. They
also help administrators to track, escalate, and respond to the incidents from their
initiation to closure. Incidents may also be registered by the users through a selfservice portal, emails, or a service desk. The service desk may consist of a call
center to handle a large volume of telephone calls and a help desk as the first line
of service support. If the service desk is unsuccessful in providing solutions against
the incidents, they are escalated to other incident management support groups or
to problem management.
The incident management support groups investigate the incidents escalated by
the incident management tools or service desk. They provide solutions to bring
back the services within an agreed timeframe specified in the SLA. If the support
groups are unable to determine and correct the root cause of an incident, errorcorrection activity is transferred to problem management. In this case, the incident
management team provides a temporary solution (workaround) to the incident; for
example, migration of a storage service to a different storage pool in the same data
center or in a different data center. During the incident resolution process, the
affected users are kept apprised of the incident status.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 785
Operations Management
Problem Management
Goal: Problem Management
Prevents incidents that share common symptoms or root causes from
reoccurring and minimizes the adverse impact of incidents that cannot
be prevented.
Key functions:

Reviews incident history to detect problems in a storage infrastructure

Identifies the underlying root cause that creates a problem
 Integrated incident and problem management tools may mark specific
incidents as problem and perform root cause analysis

Provides most appropriate solution/preventive remediation for problems

Analyzes and solves errors proactively before they become an incident/problem
Notes
A problem is recognized when multiple incidents exhibit one or more common
symptoms. Problems may also be identified from a single significant incident that is
indicative of a single error for which the cause is unknown, but the impact is high.
Problem management reviews all incidents and their history to detect problems in a
storage infrastructure. It identifies the underlying root cause that creates a problem
and provides the most appropriate solution and/or preventive remediation for the
problem. If complete resolution is not available, problem management provides
solutions to reduce or eliminate the impact of a problem. In addition, the problem
management proactively analyzes errors and alerts in the storage infrastructure to
identify impending service failures or quality degradation. It solves errors before
they turn out to be an incident or a problem.
Incident and problem management, although separate management processes,
require automated interaction between them and use integrated incident and
problem management tools. These tools may help an administrator to track and
Information Storage and Management (ISM) v4
Page 786
© Copyright 2019 Dell Inc.
Operations Management
mark specific incident(s) as a problem and transfer the matter to problem
management for further investigation. Alternatively, these tools may automatically
identify incidents that are most likely to require root cause analysis. Further, these
tools may have analytical ability to perform root cause analysis based on various
alerts. They search alerts that are indicative of problems and correlate these alerts
to find the root cause. This helps to resolve problems more quickly.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 787
Operations Management
Security Management
Goal: Security Management
Prevents occurrence of incidents/activities adversely affecting
confidentiality, integrity, and availability of information and meets
regulatory/compliance requirements for protecting information at
reasonable/acceptable costs.
Key functions:

Develops information security policies

Deploys required security architecture, processes, mechanisms, and tools
Examples of security management activities:

Managing user accounts and access policies that authorize users to use a
service

Deploying controls at multiple levels (defense in depth) to access data and
services

Scanning applications and databases to identify vulnerabilities

Configuring zoning, LUN masking, and data encryption services
Notes
Security management ensures the confidentiality, integrity, and availability of
information in a storage infrastructure. It prevents the occurrence of security-related
incidents or activities that adversely affect the infrastructure components,
management processes, information, and services. It also meets regulatory or
compliance requirements (both internal and external) for protecting information at
reasonable/acceptable costs. External compliance requirements include adherence
to the legal frameworks such as U.K. Data Protection Act 1998, U.K. Freedom of
Information Act 2000, U.S. Health Insurance Portability and Accountability Act
1996, and EU Data Protection Regulation. Internal regulations are imposed based
Information Storage and Management (ISM) v4
Page 788
© Copyright 2019 Dell Inc.
Operations Management
on an organization’s information security policies such as access control policy,
bring-your-own-device (BYOD) policy, and policy on the usage of cloud storage.
Security management is responsible for developing information security policies
that govern the organization’s approach towards information security management.
It establishes the security architecture, processes, mechanisms, tools, user
responsibilities, and standards needed to meet the information security policies in a
cost-effective manner. It also ensures that the required security processes and
mechanisms are properly implemented.
Security management team performs various activities to prevent unauthorized
access and security breaches in a storage infrastructure. For example, the security
management team manages the user accounts and access policies that authorize
users to use a service. Further, the access to data and services is controlled at
multiple levels (defense in depth) reducing the risk of a security breach if a
protection mechanism at one level gets compromised. Applications and databases
are also scanned periodically to identify vulnerabilities and provide protection
against any threats. The security management activities in a SAN include
configuration of zoning to restrict an unauthorized HBA from accessing specific
storage system ports and providing mechanisms to transport encrypted data.
Similarly, the security management task on a storage system includes LUN
masking that restricts a compute system from accessing a defined set of LUNs.
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 789
Concepts in Practice Lesson
Concepts in Practice Lesson
Introduction
This lesson covers the following topics:

Dell EMC SRM

Dell EMC Service Assurance Suite

Dell EMC CloudIQ

vRealize Operations

vRealize Orchestrator
Information Storage and Management (ISM) v4
Page 790
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Concepts In Practice
Concepts in Practice
Dell EMC SRM
A management software for automated monitoring and reporting of both traditional
and software-defined storage infrastructure. It provides visibility to the relationships
and topology from applications hosted on virtual or physical machines down to the
LUNs. It also enables administrators to analyze performance trends, capacity
utilization, and configuration compliance. With this insight, it helps administrators to
optimize storage capacity through the alignment of application workload to the right
storage tier, capacity planning, and chargeback reporting.
Dell EMC Service Assurance Suite
Offers a combination of management tools, including Smarts and M&R (formerly
known as Watch4net), to perform IT operations in a software-defined data center. It
discovers infrastructure components and details information about each one,
including configuration and inter-relationship among components. It detects and
correlates events related to availability, performance, and configuration status of
infrastructure components that may occur due to problems. It also identifies the
root causes of the problems and risk conditions. By quickly finding the root causes
and risks, it helps administrators to proactively resolve issues before they impact
the services levels.
Dell EMC CloudIQ
A no cost cloud-native application that leverages Machine Learning to proactively
monitor and measure the overall health of storage systems through intelligent,
comprehensive, and predictive analytics. The easiest way to describe CloudIQ is
that it is like a fitness tracker for your storage environment, providing a single,
simple, display to monitor and predict the health of your storage environment.
CloudIQ makes it simple to track storage health, report on historical trends, plan for
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 791
Concepts in Practice Lesson
future growth, and proactively discover and re-mediate issues from any browser or
mobile device.
vRealize Operations
A management tool that automates some of the key management operations in a
storage infrastructure. It identifies potential performance, capacity, and
configuration issues and helps remediate those issues before they become
problems. It optimizes the usage of capacity and performs capacity trend analysis.
It also collects configuration data, verifies configuration compliance with predefined
policies, and recommends/triggers necessary actions to remediate policy breaches.
This enables organizations to enforce and maintain the conformance with
configuration standards, regulatory requirements, and security hardening
guidelines. Further, it provides end-to-end visibility across storage infrastructure
components including application-to-component mapping in a single console.
vRealize Orchestrator
Orchestration software that helps to automate and coordinate the service delivery
and operational functions in a storage infrastructure. It comes with a built-in library
of pre-defined workflows as well as a drag-and-drop feature for linking actions
together to create customized workflows. These workflows can be launched from
the VMware vSphere client, from various components of VMware vCloud Suite, or
through various triggering mechanisms. vRealize Orchestrator can execute
hundreds or thousands of workflows concurrently.
Information Storage and Management (ISM) v4
Page 792
© Copyright 2019 Dell Inc.
Concepts in Practice Lesson
Assessment
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 793
Summary
Summary
Information Storage and Management (ISM) v4
Page 794
© Copyright 2019 Dell Inc.
Course Conclusion
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 795
Information Storage and Management (ISM) v4
Information Storage and Management (ISM) v4
Summary
This course covered modern technologies that drive a digital transformation,
including: cloud, big data, IoT, and machine learning, as well as modern data
center infrastructure and its elements. It also detailed intelligent storage systems
and their types, including: file, block, and object. It also listed various storage
networking technologies and their deployment as well as software-defined storage
and networking. Business continuity was also covered as well as data protection
solutions such as: replication, backup, and archiving. The course also detailed
storage infrastructure security and management processes.
Information Storage and Management (ISM) v4
Page 796
© Copyright 2019 Dell Inc.
Information Storage and Management (ISM) v4
Summary
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 797
Information Storage and Management (ISM) v4
© Copyright 2019 Dell Inc.
Page 798