Section 3 : Business Continuity
Backup and Recovery
Chapter 12
EMC Proven Professional
The #1 Certification Program in the information storage
and management industry
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Chapter Objective
Upon completion of this chapter, you will be able to:
o Describe Backup/Recovery considerations
o Describe Backup/Recovery operations
o Describe Backup topologies
o Describe backup technologies
© 2009 EMC Corporation. All rights reserved.
Lesson: Backup/Recovery Overview
Upon completion of this lesson, you be able to:
o Define Backup and backup consideration
o Describe purposes of backup
o Explain backup granularity and restore
o List backup methods
o Describe backup/recovery process and operation
© 2009 EMC Corporation. All rights reserved.
What is a Backup?
o Backup is an additional copy of data that can be used for
restore and recovery purposes
o The Backup copy is used when the primary copy is lost or
corrupted
o This Backup copy can be created by:
o Simply coping data (there can be one or more copies)
o Mirroring data (the copy is always updated with whatever is written to the
primary copy)
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It’s All About Recovery
o Businesses back up their data to enable its recovery in case of
potential loss
o Businesses also back up their data to comply with regulatory
requirements
o Backup purposes:
o Disaster Recovery
o Restores production data to an operational state after disaster
o Operational
o Restore data in the event of data loss or logical corruptions that may occur
during routine processing
o Archival
o Preserve transaction records, email, and other business work products for
regulatory compliance
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Backup/Recovery Considerations
o Customer business needs determine:
o What are the restore requirements – RPO & RTO?
o Where and when will the restores occur?
o What are the most frequent restore requests?
o Which data needs to be backed up?
o How frequently should data be backed up?
o hourly, daily, weekly, monthly
o How long will it take to backup?
o How many copies to create?
o How long to retain backup copies?
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Other Considerations: Data
o Location
o Heterogeneous platform
o Local and remote
o Number and size of files
o Consider compression ratio
o Example:
o 10 files of 1MB size Vs 10000 files of 1KB size
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Backup Granularity
Full Backup
Su
Su
Su
Su
Su
Cumulative (Differential) Backup
Su M
T W
T
F
S Su M
T
W T
F
S Su M
T
W T
F
S Su M
T
W T
F
S Su
T
W T
F
S Su M
T
W T
F
S Su M
T
W T
F
S Su
Incremental Backup
Su M
T W
T
F
S Su M
Amount of data backup
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Restoring from Incremental Backup
Monday
Tuesday
Wednesday
Thursday
File 4
Updated File 3
File 5
Incremental
Incremental
Incremental
Files 1, 2, 3
Full Backup
Friday
Files 1, 2, 3, 4, 5
Production
o Key Features
o Files that have changed since the last backup are backed up
o Fewest amount of files to be backed up, therefore faster backup and less
storage space
o Longer restore because last full and all subsequent incremental backups must
be applied
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Restoring from Cumulative Backup
Monday
Tuesday
Wednesday
Thursday
File 4
Files 4, 5
Files 4, 5, 6
Cumulative
Cumulative
Cumulative
Files 1, 2, 3
Full Backup
Friday
Files 1, 2, 3, 4, 5, 6
Production
o Key Features
o More files to be backed up, therefore it takes more time to backup
and uses more storage space
o Much faster restore because only the last full and the last cumulative
backup must be applied
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Backup Methods
o Cold or offline
o Hot or online
o Open file
o Retry
o Open File Agents
o Point in Time (PIT) replica
o Backup file metadata for consistency
o Bare metal recovery
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Backup Architecture and Process
o Backup client
o Sends backup data to backup
server or storage node
o Backup server
o Manages backup operations
and maintains backup catalog
Storage Array
Backup Data
o Storage node
o Responsible for writing data to
Application Server/
backup device
Backup Client
Backup Server/
Storage Node
Tape Library
© 2009 EMC Corporation. All rights reserved.
Backup Operation
Application Server and Backup Clients
3b
1
4
3a
5
1
Start of scheduled backup process
2
Backup server retrieves backup related
information from backup catalog
3a
Backup server instructs storage node to
load backup media in backup device
3b
Backup server instructs backup clients to
send its metadata to the backup server
and data to be backed up to storage node
4
Backup clients send data to storage node
5
Storage node sends data to backup device
6
Storage node sends media information to
backup server
7
Backup server update catalog and records
the status
2
7
Backup Server
6
Storage Node
© 2009 EMC Corporation. All rights reserved.
Backup Device
Restore Operation
Application Server and Backup Clients
1
Backup server scans backup catalog
to identify data to be restore and the
client that will receive data
2
Backup server instructs storage node
to load backup media in backup device
3
Data is then read and send to backup
client
4
Storage node sends restore metadata
to backup server
5
Backup server updates catalog
3
1
2
5
4
Backup Server
© 2009 EMC Corporation. All rights reserved.
3
Storage Node
Backup Device
Lesson Summary
Key points covered in this lesson:
o Purposes for Backup
o Considerations for backup and recovery
o Backup granularity
o Full, Cumulative, Incremental
o Backup methods
o Backup/recovery process and operation
© 2009 EMC Corporation. All rights reserved.
Lesson: Backup/Recovery Topologies & Technologies
Upon completion of this lesson, you be able to:
o Describe backup topologies
o Direct backup
o LAN and LAN free backup
o Mixed backup
o Detail backup in NAS environment
o Describe backup technologies
o Backup to tape
o Backup to disk
o Backup to virtual tape
© 2009 EMC Corporation. All rights reserved.
Backup Topologies
o There are 3 basic backup topologies:
o Direct Attached Based Backup
o LAN Based Backup
o SAN Based Backup
o Mixed backup
© 2009 EMC Corporation. All rights reserved.
Direct Attached Backups
Data
Metadata
LAN
Backup Server
Application Server
and Backup Client
and Storage Node
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Backup Device
LAN Based Backups
Application Server
Backup Server
and Backup Client
Metadata
LAN
Data
Storage Node
© 2009 EMC Corporation. All rights reserved.
Backup Device
SAN Based Backups (LAN Free)
FC SAN
LAN
Metadata
Data
Backup Server
Backup Device
Application Server
and Backup Client
Storage Node
© 2009 EMC Corporation. All rights reserved.
Mixed Backup
Application Server
and Backup Client
Metadata
FC SAN
LAN
Metadata
Backup Server
Data
Application Server
Backup Device
and Backup Client
Storage Node
© 2009 EMC Corporation. All rights reserved.
Backup in NAS Environment – Server Based
Storage
LAN
FC SAN
NAS Head
Application Server
Backup Device
(Backup Client)
Backup Request
Backup Server/ Storage Node
Data
Metadata
© 2009 EMC Corporation. All rights reserved.
Backup in NAS Environment – Serverless
Storage
LAN
FC SAN
NAS Head
Application Server
Backup Device
(Backup Client)
Backup Request
Backup Server /
Storage Node
© 2009 EMC Corporation. All rights reserved.
Data
Metadata
Backup in NAS Environment – NDMP 2-way
Storage
LAN
FC SAN
NAS Head
Application Server
Backup Device
(Backup Client)
Backup Request
Backup Server
Data
Metadata
© 2009 EMC Corporation. All rights reserved.
Backing up a NAS Device – NDMP 3-way
NAS Head
FC SAN
LAN
Storage
LAN
FC SAN
Application Server
(Backup Client)
NAS Head
Backup Device
Backup Request
Data
Backup Server
© 2009 EMC Corporation. All rights reserved.
Metadata
Backup Technology options
o Backup to Tape
o Physical tape library
o Backup to Disk
o Backup to virtual tape
o Virtual tape library
© 2009 EMC Corporation. All rights reserved.
Backup to Tape
o Traditional destination for backup
o Low cost option
o Sequential / Linear Access
o Multiple streaming
o Backup streams from multiple clients to a single backup device
Data from
Stream 1
Data from
Stream 2
Data from
Stream 3
Tape
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Physical Tape Library
Drives
Drives
Cartridges
Import/
Export
Mailbox
Linear
Robotics
System
Power Systems
Server Class Main Controller
I/O Management Unit
Front View
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Back View
Tape Limitations
o Reliability
o Restore performance
o Mount, load to ready, rewind, dismount times
o Sequential Access
o Cannot be accessed by multiple hosts simultaneously
o Controlled environment for tape storage
o Wear and tear of tape
o Shipping/handling challenges
o Tape management challenges
© 2009 EMC Corporation. All rights reserved.
Backup to Disk
o Ease of implementation
o Fast access
o More Reliable
o Random Access
o Multiple hosts access
o Enhanced overall backup and recovery performance
© 2009 EMC Corporation. All rights reserved.
Tape versus Disk – Restore Comparison
24
Minutes
Disk
Backup / Restore
108
Minutes
Tape
Backup / Restore
0
10
20
30
40
50
60
70
80
90
100 110 120
Recovery Time in Minutes*
*Total time from point of failure to return of service to e-mail users
Typical Scenario:
 800 users, 75 MB mailbox
 60 GB database
Source: EMC Engineering and EMC IT
© 2009 EMC Corporation. All rights reserved.
Virtual Tape Library
Backup Server/
Storage Node
LAN
Backup Clients
© 2009 EMC Corporation. All rights reserved.
Virtual Tape Library Appliance
FC SAN
Emulation Engine
Storage (LUNs)
Tape Versus Disk Versus Virtual Tape
Tape
Disk-Aware
Backup-to-Disk
Virtual Tape
Offsite Capabilities
Yes
No
Yes
Reliability
No inherent protection
methods
RAID, spare
RAID, spare
Performance
Subject to mechanical
operations, load times
Faster single stream
Faster single stream
Use
Backup only
Multiple
(backup/production)
Backup only
© 2009 EMC Corporation. All rights reserved.
Data De-duplication
o Data de-duplication refers to removal of redundant data. In the de-duplication
process, a single copy of data is maintained along with the index of the original
data, so that data can be easily retrieved when required. Other than saving disk
storage space and reduction in hardware costs, (storage hardware, cooling,
backup media, etc), another major benefit of data de-duplication is bandwidth
optimization.
© 2009 EMC Corporation. All rights reserved.
Lesson Summary
Key points covered in this lesson:
o Backup topologies
o Direct attached, LAN and SAN based backup
o Backup in NAS environment
o Backup to Tape
o Backup to Disk
o Backup to virtual tape
o Comparison among tape, disk and virtual tape backup
© 2009 EMC Corporation. All rights reserved.
Chapter Summary
Key points covered in this chapter:
o Backup and Recovery considerations and process
o Backup and Recovery operations
o Common Backup and Recovery topologies
o Backup technologies
o Tape, disk, and virtual tape
© 2009 EMC Corporation. All rights reserved.
Concept in Practice – EMC NetWorker
Additional Task
Research on EMC Networker,
EmailXtender, DiscXtender,
Avamar & EDL
NetWorker Server
NetWorker Client
Data Tracking
& Management
Tracking
Data
Data Source
Recovery
Data
Backup
Data
Backup Device
Backup
Data
Recovery
Data
Storage Node
© 2009 EMC Corporation. All rights reserved.
Check Your Knowledge
o What are three primary purposes for backup?
o What are the three topologies that support backup operation?
o Describe three major considerations of backup/recovery.
o What are the advantages and disadvantages in tape and virtual
tape backups?
o What are the three levels of granularity found in Backups?
o How backup is performed using virtual tape library?
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