1. VMware vSphere Backup
in Cybozu Labs
Oct 22, 2010
HOSHINO Takashi
Cybozu Labs, Inc.
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2. Contents
• Backup operation in Cybozu Labs
– VMware vSphere environment
– Backup software
– Backup policy
• Data amount and performance
– Virtual disk and its archive size
– Backup execution time
– Differential vs incremental
– Gzip vs lzop
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3. VMware vSphere Environment
LAN
ESX(i) Host
Vmbkp
Server vCenter
Backup
server server
ESXi Host ESXi Host ESXi Host
4 cpus, 2GB memory
78 VMs exist
SAN
Backup VM VM VM VM
Storage Storage Storage Storage Storage
2TB 2TB 2TB 2TB 2TB 3

4. Backup Software
• Vmbkp developed by Cybozu Labs
– Online backup
– Multi-generation management
– Fast access to latest archives
– Command-line interface
Generation 1 Generation 2 Generation 3
Time
Now
Full image Digest Rdiff image Dependency 4

5. Backup Policy
• Backup all VMs every weekend
• Keep at least 3 generations
• Delete archives of deleted VMs after 1 month
VM1
VM2 Delete VM2
Delete VM2 archive
VM3
Failed
2 months ago A month ago Now
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6. Total Size of Virtual Disks
• Provisioned disks contain 41% zero blocks, not allocated really.
• Archive files do not include zero blocks and are gziped to 31% size. 6

7. Total Size of Reverse Differences
• 2.7% of disk are updated every week
• 6.0% of update data overwrite zero blocks (newly allocated) 7

8. Backup Execution Time
• 4.4TB(2.6TB nonzero) backup takes 22 to 25 hours
• Average throughput of non-zero blocks is 30.4MB/s 8

9. Backup Archive Size
• Archive size is increasing gradually by keeping multi-generations
• Archive size will be saturated because we hold limited number of generations 9

10. Each Virtual Disk Size (Oct 16)
• Disk usage varies widely for each virtual disk
• Currently vSphere supports up to 256GB virtual disk 10

11. Differential vs Incremental Backup
• Incremental backup is faster than differential backup
• Additional setting is required to enable incremental backup 11

12. Gzip vs Lzop
Archive Size Compression Throughput


• Lzop is better for high compression throughput
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Data from operation-test • Currently Vmbkp uses gzip

13. Summary
• Vmware vSphere backup in Cybozu Labs
– 78 VMs in 3 ESXi hosts and 2TB x4 iSCSI storages
– Backup all VMs every weekend keeping past generations
• Backup data and archive
– Totally 4.4TB provisioned virtual disks with 41% zero blocks
– Archives consumes only 1TB for 4 generations
• Backup performance
– Incremental backup is faster than differential one
– Lzop is better than gzip but not implemented yet
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