CTP files when backup VM in CSV

[abigot@serians.fr]

hi!
I use VEEAM to backup a Hyper-V cluster (2 nodes) labtest. I use Software VSS (so : onhost mode)
*.ctp files are created in VM folders (so we can't delete all VM files when removing a VM.)
CTP files seems to come with CBT...
is there a fix to delete these files automatically ?
regards,

[Vitaliy S.]

Arnaud,

You're right. Veeam CBT driver keeps track of changing data blocks in virtual disks via special .ctp files stored next to VM disk files.

Could you please clarify one thing for me please - you're saying that you cannot delete this files at all, right? What does the corresponding error message say?

Thanks!

[abigot@serians.fr]

thank you for reply.
sorry, but the problem disappears...(the problem was *.ctp cannot be deleted because they were in use by a process.)
So I will go on testing .
thanks.

[Vitaliy S.]

Yep, looks like these files were still locked by Veeam process when you tried to remove them.

[Gostev]

You don't want to delete these files. You should only delete if you decide uninstall Veeam Backup & Replication from your environment (as well as our Hyper-V integration components from all hosts). Thanks!

[smurteira]

But how long does it take for these files to disappear? If or when they disappear does it also delete the folder? Leaving these folders and files out there makes a mess out of csv storage. I'd like to look at my csv storage and know what's in there and not have to guess which ones have files in them and which ones don't. I can get rid of the .ctp files by live migrating my vms out of the host that has a lock on the file, then once the host is rebooting, you can just delete the file and follow the procedure for any other host that may have a lock on the file. But live migrating the vms and rebooting a host can't be the answer we are looking for here. There has to be a reason/answer as to why these files don't go away after you delete a vm.

[Gostev]

There has to be a reason/answer as to why these files don't go away after you delete a vm.

Well, that's an easy one. If you delete VM using any Microsoft tool, it simply does not know about any 3rd party files belonging to this VM, and thus those are not included in the deletion process. It's a good point though, we should add functionality to our Hyper-V intergration components to automatically clean up these files after VM has been moved or deleted.

[Gostev]

Actually, it appears that this functionality is already in place. The obsolete CTP files clean up job is an automated operation that is performed daily. If you do not see this happening in your environment, we would like to investigate this closer with the debug logs (it could be that there are certain scenarios that clean up logic is missing).

By the way, to ensure transparent support for Live Migration, CTP files are created on EACH host of the cluster for EACH VM we protect, and they will not be deleted by cleanup logic until VM is either removed completely, or changed to be a non-clustered resource. So it is normal to still see CTP files after live migrating VM to another host.

Thanks!

[smurteira]

Thanks Gostev. Is there a way for me to kickoff the cleanup myself? PowerShell maybe?

[Gostev]

I don't believe this is available through PowerShell. Besides, why not just wait for just 12 hours (on average) and let it happen automatically?

[markharford]

Any update on this Gostev? It's proving a real nuisance.

Also I have just found that a backup taken straight after a live migration of storage location fails.

Nothing obvious in the log files.

[Gostev]

Update on what specifically?

[markharford]

Ah sorry, I meant an update on a way to manually kick off the cleanup of obsolete CTP files.

[Gostev]

No plans to add that. All unneeded files should be cleaned up automatically within 24 hours.