warning after backup of running Hyper-V VM

[horst]

Hello,

I have installed Veeam B&R v7 on a Windows 2012 Hyper-V Host.
On the host there is a virtual windows 7 VM running. At the moment the VM has one snapshot, for testing.
After the Veeam Backup Yesterday I got the following backup-result:

27.08.2013 21:00:38 :: Cannot use CBT: Change tracking files are not specified for VHDX 'server-OS_FAA9ED5A-5C7C-48C8-8703-E6D6FFC9D477.avhdx'

What does this mean?

[veremin]

I believe it’s the snapshot presence that results in the said issue. The Hyper-V CBT mechanism is implemented as a filter driver that tracks changed blocks in virtual disks. Probably, the snapshot is being seen as an additional virtual disk and VB&R tries to check the changed block on it without any result.

So, in order to utilize CBT mechanism, it might be worth consolidating existing snapshot first.

Thanks.

[horst]

ok, thanks for your reply. I will keep an eye on that

[veremin]

I’ve moved this discussion to the corresponding subforum. Anyway, kindly, keep us updated about the results you get.

[horst]

strangely enough the backup worked last night without any error, even though I had not changed anything on the vm and it still has the snapshot...

[foggy]

Good to know everything is working now. In case of the issue shows up again, I recommend to contact technical support directly for job logs investigation.