Hyper-V VEA backup of VMs on cluster shared volumes (CSV)
During Data Protector VEA backups often messages were observed like the following, especially if several VMs were involved in the backup. Smaller backups of say 5 VM were running fine.
Only if larger number of VMs were involved and these were distributed over several CSV and were accessed via different Hyper-V server the issue could be observed.
Error in session report
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[Major] From: OB2BAR_VSSBAR@system.domain "HyperV" Time: 11.10.2012 16:13:52
Cannot perform backup of:
'/Microsoft Hyper-V VSS Writer/Virtual Machines/Backup Using Child Partition Snapshot\VSAP-BHS301',
which contains data in:
C:\ClusterStorage\Volume2\VSAP-BHS301\Virtual Machines\7B36324F-E064-4948-AA14-D189EBC32673.xml
C:\ClusterStorage\Volume2\VSAP-BHS301\Virtual Machines\7B36324F-E064-4948-AA14-D189EBC32673\*
C:\ClusterStorage\Volume2\VSAP-BHS301\VSAP-BHS301_disk_1.vhd
C:\ClusterStorage\volume2\vsap-bhs301\vsap-bhs301_disk_2.vhd
There are two parameters that can help with the problem.
'omnirc' local environment variable: OB2VSS_TIMEOUT
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The timeout has to be set on the Hyper-V servers where vssbar is running (not on the VEAgent host) and that it's long enough. The default is 180 min
'global' environment variable: CellResourceTimeout
Default is 7200 seconds (2 hours)
Issue was solved by setting
1. on all the 5 VSS hosts, omnirc variable "OB2VSS_TIMEOUT=2880
2. global variable on cell manager "CellResourceTimeout=86400
27 nodes could successfully be backed up up this way.
The 'omnirc' file does not exist by default, it can be created using Notepad and saved in the following location
Program Data -> Omniback -> omnirc
When saving the file, make sure that it has no extension, like 'txt' or 'tmpl'. The Data Protector INET services must be stopped and restarted after creating or editing this file
The 'global' file is found on the cell manager:
Program Data -> Omniback -> Config -> Server -> Options -> global
After making the edit, save the file, stop and restart Data Protector