CBT Map was changed ReFS

[PC535]

Every once and awhile (few weeks) I get the message Changed block tracking map was changed for volume (.....)
These disks are setup in Windows Storage spaces, with a cache. (Mirrored 8TB Drives)
Disks are formatted with ReFS
Windows Server 2019 (Desktop Experience)
File system has not been unmounted or system rebooted.
Naturally this is rather annoying an instead of the backups taking a few minutes they take hours to read all the data from the mirrored drives.

Has anybody else seen this? or know of a resolution? I read the help topic which discuss if the volume was modified by another operating system (like linux) but that is not the case here.

[HannesK]

Hello,
it's hard to guess. Usually I see that when I change disk size. Do you have a support case for that? Support might be able to find something.

Best regards,
Hannes

[PC535]

I have not opened a support case yet.
And just to cover what you mentioned the disks have not changed in size, the volume has been untouched other than data being read/written to it.

[Dima P.]

Hello Peter,

Such behavior is unexpected, so please raise a support ticket and I'll pass it directly to QA team. Thank you in advance!

[PC535]

I've opened a case 03968533.

[Dima P.]

So far it looks like the issue is related to the Windows Storage Spaces. We will check this behavior with the upcoming Veeam B&R v10 + VAW v4 as integration with Storage Spaces is provided in the upcoming release. Stay tuned!

[SBarrett847]

On a similar note - if I expand a disk on a server being backed up it resets the CBT map for all of the attached disks, is this expected behavior?

[HannesK]

Usually I see that when I change disk size

yes, that is expected