I recently had to move a Windows Server 2016 VM over to another cluster (2012R2 to 2016 cluster)  and to do so I uses shared nothing live migration. After the VM was happily running on the new cluster I kicked of a Veeam backup job to get a first restore point for that VM. Better safe than sorry right?

But the job and the retries failed for that VM. The error details are:

Failed to create snapshot Compellent Replay Manager VSS Provider on repository01.domain.com (mode: Veeam application-aware processing) Details: Job failed (‘Checkpoint operation for ‘FailedVM’ failed. (Virtual machine ID 459C3068-9ED4-427B-AAEF-32A329B953AD). ‘FailedVM’ could not initiate a checkpoint operation: %%2147754996 (0x800423F4). (Virtual machine ID 459C3068-9ED4-427B-AAEF-32A329B953AD)’). Error code: ‘32768’.
Failed to create VM recovery snapshot, VM ID ‘3459c3068-9ed4-427b-aaef-32a329b953ad’.

Also when the job fails over to the native Windows VSS approach when the HW VSS provider fails it still does not work. At first that made me think of a bug that sued to exist in Windows Server 2016 Hyper-V where a storage live migration of any kind would break RCT and new full was needed to fix it. That bug has long since been fixed and no a new full backup did not solve anything here. Now there are various reasons why creating a checkpoint will not succeed so we need to dive in deeper. As always the event viewer is your friend. What do we see? 3 events during a backup and they are SQL Server related.

On top of that the SQLServerWriter  is in a non retryable error when checking with vssadmin list writers.

It’s very clear there is an issue with the SQL Server VSS Writer in this VM and that cause the checkpoint to fail. You can search for manual fixes but in the case of an otherwise functional SQL Server I chose to go for a repair install of SQL Server. The tooling for hat is pretty good and it’s probably the fastest way to resolve the issues and any underlying ones we might otherwise still encounter.

After running a successful repair install of SQL Server we get greeted by an all green result screen.

So now we check vssadmin list writers again to make sure they are all healthy if not restart the SQL s or other relevant service if possible. Sometime you can fix it by restarting a service, in that case reboot the server. We did not need to do that. We just ran a new retry in Veeam Backup & Replication and were successful.

There you go. The storage live migration before the backup of that VM made me think we were dealing with an early Windows Server 2016 Hyper-V bug but that was not the case. Trouble shooting is also about avoiding tunnel vision.