vCenter (VM) backup using CommVault VSA fails to do application consistent backup but crash-consistent works fine. https://ontap-netapp.blogspot.com/

1. ‘vCenter VM’ CommVault VSA Backups
have been completing with one or more
errors on random basis, sometimes
regular: [failing on ‘VSS’ quiescing then
falls back on crash-consistent backup]
Protecting vCenter using the Virtual Server Agent:
If vCenter is running on a virtual machine, you can use an application-consistent backup
using the Virtual Server Agent to protect the virtual machine as well as the vCenter database
and files. This is the recommended method for backing up a vCenter Server Appliance.
Error:
Unable to create snapshot of VM [VCS], trying without quiescing file system
Job ID: xxxxx
Status: Completed w/ one or more errors
Client: =vCenter Server
Agent Type: VSA
Instance: VMware
Backup Set: defaultBackupSet
Subclient: VC-VM-AC [AC stands for Application Consistent here, it’ just a naming
convention]
Following VSS errors are seen in the Windows event log:

2. Root cause:
Looked up for this error on google, and found MS articles pointing to: Invalid profile entry
(*.bak) which cannot resolve the SID of the Shadow Copy writer.
Found number of *.bak profiles on : VCS
There is a Microsoft recommended solution:
1. Open the registry editor with regedit.
2. Make a backup of the registry.
3. Expand to this location and look for profile entry that has a ".bak" value appended:
HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows NTCurrentVersionProfileList
4. Select and delete the entries with the extra ".bak"
5. Reboot the VM.
Courtesy: https://blogs.technet.microsoft.com/askpfeplat/2017/07/31/windows-backups-
failing-with-associated-vss-8193-errors/
ashwinwriter@gmail.com
Aug, 2018