PROBLEM
Running the command 'vssadmin list writers' from command prompt inside the guest virtual machine shows that the System Writer is in a failed state as below:
Writer name: 'System Writer'
Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Instance Id: {c199e334-3489-4c08-b1ed-a3ea68628794}
State: 8 Failed
Last error: Inconsistent shadow copy
The Windows Application Event Log inside the guest VM also shows the below Error Event at the time of failure:
Event ID: 2
Source: vmicvss
Level: Error
The VSS writer System Writer failed with status 8 and writer specific failure code 0x800423F0
CAUSE
The Windows System Writer is failing, thus VM Backup is unable to complete an application consistent backup of this VM due to a failure with the Windows Cryptographic Services.
A discussion thread about this issue can be found here:
SOLUTION
- Disable "Backup (volume checkpoint)" on the running VM from the host under Integration Services
- Run a Backup of the VM
- Re-enable the "Backup (volume checkpoint)" on the running VM from the host under Integration Services as above
- Reboot the VM and the next backup should be successful