Differencing Disk VMs - Changed Block Tracking

[allister.wade]

Doing some testing with Veeam before putting into production. We have a set of VM's (approx. 20) utilising differencing disks included in the backup. So far I've just plonked all the VMs bar some problematic ESXi to Hyper V converted Server 2003 machines in the same job following the advice of the Dell "How To" for Veeam and the DR4100 backup appliance we are using.

Not mentioned in this guide though are settings for Changed Block Tracking and today after adding the differencing disk VMs to the backup yesterday we have the following warning on each of these VMs:

Cannot use CBT: Chang tracking files are not specified for VHDX 'ARCSIMGOLDEN.VHDX'

ARCSIMGOLDEN.VHDX is the reference disk for the differencing VHDX's.

Any chance someone can provide an explanation of this and any changes we should make? Should we just make a new job for the differencing machines and disable Changed Block Tracking?

[Vitaliy S.]

Hi Allister,

What version (including build number) of Veeam B&R are you at?

Thanks!

[allister.wade]

Hi

7.0.0.871

[Vitaliy S.]

I have talked to our QC team and there are no known issues around CBT and differencing disks that would apply to your case, everything should be working fine. Can you contact our technical team to verify your Hyper-V configuration and check the debug logs?