Virtualization Terminology and Concepts
© 2011 VMware Inc. All rights reserved
Agenda
 Virtualization Overview
 vSphere / Virtualization Concepts
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Virtualization Overview – Resource Optimization
Physical World
Virtual World
VM density
matters!
1:1
1:1
1:1
1:1
1:1
Many:1
1:1
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1:1 relationship between
applications and hardware
Many:1 relationship between
applications and hardware
No resource optimization
Densities are increased
improving resource optimization
without sacrificing performance
Virtualization Overview – Advantages to Virtualization
CPU Optimization / Scheduling
VMware can account for CPU and I/O needs of virtual machines by dynamically allocating more resources and larger
processor timeslices to VMs. Based on this technology, a single vCPU virtual machines can operate better than an
oversized multiple vCPU VMs.
Memory Oversubscription / Optimization
More efficient use of physical RAM by reclaiming unused physical memory and consolidating identical memory pages among
VMs on a host.
DRS with Resource Pools
Dynamically load balance VMs across a cluster so applications get required resources when they need them – a “safety net”
that lets administrators run individual servers at higher utilization levels while meeting service level agreements.
Direct Driver Model
VMware ESX can achieve very high I/O throughput and can handle the I/O requirements for more VMs simultaneously
requesting hardware resources.
Support for Large Memory Pages and Nested/Extended Page Tables
Optimize memory access and can provide substantial performance benefits for mission critical, memory-intensive
applications, can reduce CPU resource consumption by up to 15%.
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Virtualization Overview – Capacity versus Overhead
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vSphere / Virtualization Concepts - Glossary of Terms
Datacenter:
A required structure under which hosts and their associated virtual machines are added to vCenter Server.
vCenter Server supports multiple datacenters. A host can be managed under only one datacenter.
Cluster:
A server group in the virtual environment. Clusters enable a high-availability solution.
Resource pool A division of computing resources used to manage allocations between virtual machines.
Datastore:
Virtual representations of combinations of underlying physical storage resources in the datacenter. A
datastore is the storage location (for example, a physical disk, a RAID, or a SAN) for virtual machine files.
vDS:
A distributed virtual switch (vDS) is an abstract representation of multiple hosts defining the same vSwitch
(same name, same network policy) and port group. These representations explain the concept of a virtual
machine being connected to the same network as it migrates among multiple hosts.
dvPort group: A port group associated with a vDS. The port group specifies port configuration options for each member
port. A dvPort group defines how a connection is made through the vDS to the network. See also vDS
(distributed virtual switch).
dvPort :
A distributed virtual port on a vDS that connects to a host’s service console or VMkernel or to a virtual
machine’s network adapter. See also vDS (distributed virtual switch).
Host:
A computer that uses virtualization software to run virtual machines. Also called the host machine or host
computer. The physical computer on which the virtualization (or other) software is installed.
Hypervisor:
A platform that allows multiple operating systems to run on a host computer at the same time.
VMware Technical Publications Glossary:
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http://www.vmware.com/pdf/master_glossary.pdf
vSphere / Virtualization Concepts - vSphere
vCenter Server
Application
Services
• Host Profiles
• Orchestrator
• Linked Mode
• Update Mgr
• HA
• FT
• vMotion/S vMotion
• Data Recovery
• VMsafe APIs
• vShield Zones
• Hot Add
• # of Hosts, VMs
Availability
Security
Scalability
Compute
Storage
Network
• ESX/ESXi
• DRS/DPM
• Memory
Overcommit
• VMFS
• Thin Provisioning
• Storage I/O Control
• Storage APIs
• Distributed Switch
• Network I/O Control
VMware vSphere 4.1
Infrastructure
Services
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vSphere / Virtualization Concepts - VMware vCenter Server
vCenter Server v5 Scalability
Hosts per vCenter Server: 1,000
Concurrent vSphere Clients: 100
Powered‐on virtual machines per vCenter Server: 10,000
Registered virtual machines per vCenter Server: 15,000
vSphere v5 Configuration Maximums Link: http://www.vmware.com/pdf/vsphere5/r50/vsphere-50-configuration-maximums.pdf
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vSphere / Virtualization Concepts – VMware vCenter Server
vCenter Server
Scalability
vCenter Server
Linked Mode
• Standard vSphere
Client can access
inventory across
multiple vCenters
• View and search
across a group of VC
Servers
Visibility
Host Profiles
vCenter Orchestrator
• Simplified setup and
change management
for ESX hosts
• Workflow engine for
orchestrating
virtualization
• Easy detection and
remediation of
non-compliance with
standard configurations
• Automate manual,
repeatable steps by
drag and drop
interface
VMware vSphere
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Automation
vSphere / Virtualization Concepts – VMware Update Manager
Update Manager is a simple patch
management solution for the virtual
infrastructure. It applies security updates and
bug fixes to reduce risks from vulnerabilities.
Update Manager is a vCenter Server plug-in
that allows you to apply updates and patches
across all ESX/ESXi hosts. It is used to install
and update third-party software on hosts and
it is used to upgrade virtual machine
hardware, VMware Tools, and virtual
appliances.
It enables centralized, automated patch and
version management from within VMware
vCenter Server. Security administrators can
compare ESXi hosts, as an example, against
baselines to identify and remediate systems
that are not in compliance.
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vSphere / Virtualization Concepts – Hypervisor (Compute)
VMware Architecture
 True thin hypervisor (ESX 4i = 70 MB Foot Print)
 No general-purpose OS
 Direct driver model = I/O scaling
 Drivers optimized for VMs
 Page Sharing = Greater Density
 Hypervisor owns the resources
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vSphere / Virtualization Concepts – DRS (Compute)
VMware Distributed Resource Scheduler (DRS) aggregates computing capacity across a
collection of servers into logical resource pools and intelligently allocates available resources
among the virtual machines based on pre-defined rules that reflect business needs and changing
priorities.
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vSphere / Virtualization Concepts – DRS Host Affinity (Compute)
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•
Host Affinity rules sets constraints that restrict placement between a group of virtual
machines and a group of hosts in a VMware DRS enabled cluster.
•
Host Affinity rules are useful for enforcing host-based ISV licensing models, as well as for
keeping sets of virtual machines on different racks or blade systems for availability reasons.
vSphere / Virtualization Concepts – DPM (Compute)
VMware Distributed Power Management (DPM), included with VMware DRS, automates power
management and minimizes power consumption across the collection of servers in a VMware DRS
cluster.
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vSphere / Virtualization Concepts – Memory (Compute)
 Transparent Page Sharing (TPS)
In ESX / ESXi, the redundant VM memory pages are identified and only stored once in physical
memory. This means that pages with identical content can be shared regardless of when, where, and
how those contents are generated. ESX scans the content of guest physical memory for sharing
opportunities. Instead of comparing each byte of a candidate guest physical page to other pages, an
action that is prohibitively expensive, ESX uses hashing to identify potentially identical pages.
 Memory Ballooning
Due to the virtual machine’s isolation, the guest operating system is not aware that it is running inside
a virtual machine and is not aware of the states of other virtual machines on the same host. When the
hypervisor runs multiple virtual machines and the total amount of the free host memory becomes low,
none of the virtual machines will free guest physical memory because the guest operating system
cannot detect the host’s memory shortage. Ballooning makes the guest operating system aware of the
low memory status of the host utilizing the Host Ballooning driver in the VMware Tools on the Guest
OS.
 Memory Compression
The idea of memory compression is very straightforward: if the swapped out pages can be compressed
and stored in a compression cache located in the main memory, the next access to the page only
causes a page decompression which can be an order of magnitude faster than the disk access. With
memory compression, only a few uncompressible pages need to be swapped out if the compression
cache is not full. This means the number of future synchronous swap-in operations will be reduced.
vSphere v4.1 Memory Performance Best Practices: http://www.vmware.com/files/pdf/techpaper/vsp_41_perf_memory_mgmt.pdf
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vSphere / Virtualization Concepts – VMFS (Storage)
VMware® vStorage Virtual Machine File System (VMFS) is
a high-performance cluster file system that provides storage
virtualization optimized for virtual machines. Each virtual
machine is encapsulated in a small set of files and VMFS is the
default storage system for these files on physical SCSI disks
and partitions.
Key Benefits
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•
Greatly simplify virtual machine provisioning and
administration by efficiently storing the entire virtual
machine state in a central location.
•
Run multiple instances of VMware ESX™ to access the
same virtual machine storage concurrently.
•
Support virtualization-based distributed infrastructure
services using VMware vCenter Server, VMware
VMotion™, VMware DRS and VMware HA.
vSphere / Virtualization Concepts – Thin Provisioning (Storage)
VMware vStorage Thin Provisioning dramatically increases
virtual machine storage utilization by enabling dynamic
allocation and intelligent provisioning of physical storage
capacity.
Key Benefits
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•
Increase storage utilization
•
Enhanced application uptime
•
Simplified management
vSphere / Virtualization Concepts – Storage I/O Control (Storage)
Storage I/O Control (SIOC) monitors
the latency of I/Os to datastores at
each ESX host sharing that device.
When
the
average
normalized
datastore latency
exceeds a set
threshold (30ms by default), the
datastore is considered to be
congested, and SIOC kicks in to
distribute
the
available
storage
resources to virtual machines in
proportion to their shares. This is to
ensure that low-priority workloads do
not monopolize or reduce I/O
bandwidth for high-priority workloads.
SIOC accomplishes this by throttling
back the storage access of the lowpriority virtual machines by reducing
the number of I/O queue slots available
to them. Depending on the mix of
virtual machines running on each ESX
server and the relative I/O shares they
have, SIOC may need to reduce the
number of device queue slots that are
available on a given ESX server.
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vSphere / Virtualization Concepts – Storage APIs (Storage)
vStorage APIs takes the benefits of
Consolidated Backup and makes
them significantly easier to deploy,
while adding several new features that
deliver efficient, scalable backup, and
restore of virtual machines. vStorage
API make it possible to offload backup
processing
from
ESX
servers,
ensuring that you deliver the best
consolidation ratios without disrupting
applications and users. The vStorage
API for Data Protection enables
backup tools to directly connect the
ESX servers and the virtual machines
running on them without any
additional software installation. They
add the ability to enable backup tools
to do efficient incremental, differential,
and full-image backup and restore of
virtual machines.
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vSphere / Virtualization Concepts – vDS (Network)
vNetwork Distributed Switch (vDS) - Datacenter-level Virtual
Networking
• Aggregated view of virtual
App
App
App
App
App
OS
OS
OS
OS
OS
networking
• Datacenter level networking
(versus host level)
• Historical statistics follow the VM
• A unified infrastructure for networking
vNetwork Distributed
Switch
vSwitch
vSwitch
vSwitch
services (monitoring, filtering, mgmt
via PVLANs)
• Simplified setup and change;
seamless addition of capacity
• Easy troubleshooting, monitoring
and debugging
• Enables new security services
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vSphere / Virtualization Concepts – Network I/O Control (Network)
VMware Network I/O Control (NetIOC)
provides users with the following features:
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Isolation: ensure traffic isolation so that
a given flow will never be allowed to
dominate over others, thus preventing
drops and undesired jitter.
•
Shares: allow flexible networking
capacity partitioning to help users to deal
with over-commitment when flows
compete aggressively for the same
resources.
•
Limits: enforce traffic bandwidth limit on
the overall vDS set of dvUplinks.
•
Load-Based Teaming: efficiently use a
vDS set of dvUplinks for networking
capacity
vSphere / Virtualization Concepts – HA (Availability)
VMware High Availability (HA) provides easy to use, cost-effective high availability for applications running in virtual
machines.
Key Benefits include:
•
Minimize unplanned downtime and IT service disruption.
•
Eliminate the need for dedicated standby hardware and the installation of additional software.
•
Enable affordable uniform high availability across the entire virtualized IT environment.
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vSphere / Virtualization Concepts – FT (Availability)
VMware Fault Tolerance (FT)
• Single identical VMs running in
lockstep on separate hosts
• Zero downtime, zero data loss
App
OS
VMware ESX
FT
App
App
OS
OS
VMware ESX
failover for all virtual machines
in case of hardware failures
• Integrated with VMware
HA/DRS
• Zero downtime, zero data loss
• No complex clustering or
X
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specialized hardware required
• Single common mechanism for
all applications and OS-es
vSphere / Virtualization Concepts – vMotion (Availability)
VMware vMotion enables the live
migration of running virtual machines from
one physical server to another with zero
downtime, continuous service availability,
and complete transaction integrity.
VMotion is a key enabling technology for
creating the dynamic, automated, and
self-optimizing datacenter.
Key Benefits
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•
Improve availability by conducting
maintenance
without
disrupting
business operations.
•
Ability to move virtual machines
within server resource pools to
continuously align the allocation of
resources to business priorities
vSphere / Virtualization Concepts – Storage vMotion (Availability)
VMware Storage vMotion enables live
migration for running virtual machine disk
files from one storage location to another
with no downtime or service disruption.
Key Benefits:
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•
Simplify storage array migrations and
storage upgrades.
•
Dynamically optimize storage I/O
performance.
•
Efficiently utilize storage and manage
capacity.
vSphere / Virtualization Concepts – vDR (Availability)
VMware Data Recovery (vDR) enables quick,
simple and complete data protection for your
virtual machines. vDR is a disk-based backup
and recovery solution and is fully integrated with
VMware vCenter Server to enable centralized and
efficient management of backup jobs and also
includes data de-duplication to save on disk
storage for your backups.
Key Benefits:
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•
Provides fast and efficient data protection
for all your virtual machines, even those
powered off or migrating between physical
hosts.
•
Reduces the cost of backing up virtual
machines and minimizes the backup window
using a snapshot based (agentless)
approach.
•
Simple configuration and management of
backup jobs through a central interface
within VMware vCenter Server.
•
Reduces disk space consumed by backup
data with built in data de-duplication
technology
vSphere / Virtualization Concepts – vShield Zones (Security)
VM-level Security for Your Private Cloud
• Self-learning, self-configuring
firewall Service
• VMotion and networkconfiguration aware trust zones
• Dynamic firewall policy using
application protocol awareness
• Dynamic security capacity using
infrastructure services
• Security policies auto-adapt
to network reconfiguration
or upgrades
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Questions ?
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