@jb-backup , sounds like you have stale snapshots in your Hypervisor.

Can you check on the Hypervisor side and see what snapshots are remaining?  You likely will need to manually delete them and potentially speak to the vendor about what happened.

@Mike Struening , thanks for your response.  I’m not sure what you mean by snapshot in Hypervisor side.  If I look in Microsoft System Center VMM, what am I looking for?  Is this the same as checkpoint?

I have a case open with CV; hopefully, they have an answer for me as to what happened.

Can you share the case number?  I want to follow up with the incident.

Based on the error, Hyper-V (assuming Hyper-v) is creating snapshots of the VMs and can’t because older ones are still around.

Hyper-V likely calls them something else (checkpoints, if I recall correctly).  Best for us to see what the support person finds and update the thread here.

@Mike Struening, the case is 220301-599.   I did some digging around in Hyper-V and found that most of the checkpoint are indeed old.  Now the big question, is it the Hyper-V making these snapshots, or the Commvault software? 
 

Thanks, @jb-backup !  Initial thought is potentially outside of CV, though it could also be a checkpoint we think was deleted but wasn’t….too many options.

I see you are with Will who is a brilliant guy.  you’re in good hands!

Sharing the solution:

We followed the initial advice to check for old/stale snapshots or checkpoint. That was indeed the problem. Our Windows Admin migrated some virtuals from the old clusters to this new cluster, and those snapshots caused the problems. We cleaned those up and everything is well now. You can close this case.