Post on 31-Dec-2015
description
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CBT AND ABMvRanger Pro 4.5
6/16/2010
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Image-Based Backup: Activities Impacting Performance
1: Scanning 3: Writing
6/16/2010
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2: Reading
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How CBT and ABM work together
A typical disk layout, before 1st backup
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Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
0
0 0
0
6/16/2010
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Fulls: without CBT or ABM
• All blocks must be scanned and read• Unallocated and zero blocks are both read as zeros• vRanger engine removes all “whitespace” on writes
6/16/2010
Scan and Read Write
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
00
0
0
0
0
0
0
0
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Fulls: with CBT
• Does not scan unallocated blocks• Zeros and deleted blocks are scanned and read• vRanger engine removes “whitespace” on writes
6/16/2010
Scan and Read Write
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
00
00
0
0 0
0
00
0
0
00
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Fulls: with ABM
• Does not scan zero nor deleted blocks• Unallocated blocks are scanned and read• vRanger engine removes un-allocated “whitespace”
6/16/2010
Scan and Read Write
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
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Fulls: with Both ABM and CBT
• Scans the minimum set of blocks: no zero nor unallocated whitespace, no deleted blocks
6/16/2010
Scan and Read Write
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
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How CBT and ABM work together
A typical disk layout, after 1st backup
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
6/16/2010
0
0
0
0
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Incrementals: without ABM or CBT
• All blocks are scanned• Only changed blocks are read• vRanger engine removes “whitespace”
6/16/2010
Scan and Read
0
0
0
0
Write
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
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Incrementals: with CBT
• Changed blocks are “presented” to vRanger by vSphere API• No scanning necessary• Only changed blocks are read and written
6/16/2010
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
Read and WriteFrom vStorage API
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Incrementals: with ABM
• Active blocks are presented to vRanger by Windows NTFS• Scanning includes only active and unallocated blocks (zero
and inactive blocks are not included in the scan)• Only changed, active blocks are read and written
6/16/2010
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
Read and WrittenScanned
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Incrementals: Both ABM and CBT together
• No scanning• Only active and changed blocks are read and written
6/16/2010
Active Block
Unallocated Block
Deleted Data
Changed Block
0 Zero Block
Read and WrittenFrom vStorage
API