- Altaro VM Backup reports a Backup failure due to a Microsoft Shadow Copy error indicating a VSS failure within the Guest, as below:
The operation encountered an error. (Error code 'BASEBACKUPCONTROLLER_016')
Additional information is available:
Hyper-V reported that there was a problem taking an internal shadow copy on this VM. This may be a temporary problem and the Microsoft recommended way to fix this error is to wait ten minutes and then repeat the operation, up to three times. (Error code 'VSS_4104')
- The Windows Application Event Log inside the guest VM also shows the below Error Event at the time of failure:
Log Name: Application
Event ID: 8193
Volume Shadow Copy Service error: Unexpected error calling routine RegOpenKeyExW(-2147483646,SYSTEM\CurrentControlSet\Services\VSS\Diag,…). hr = 0×80070005, Access is denied.
The user does not have appropriate permissions to the Microsoft VSS registry keys.
More details about this issue can be found here:
- Go to the the details tab of the above event log entry (Event ID 8193)
- Here you can see the information about the User account that generated the error.
- Take note of the user mentioned after the “- User: Name:” portion
- Give that user full permission to the registry key below:
- Reboot the VM
- Try the backup again and it should be successful