Veeam, Arcserve, and CTK files

[Vejete]

IHAC who for a few months will need to use both Veeam and Arcserve to backup the same VMs. Both use CBT, and our testing thus far implies that there may be some undesirable interaction between the two backup solutions and the Changed Block Tracking (CTK) map files for each VM. About 40% of VMs backed up with both solutions are now showing corrupt CBT which makes necessary creating and deleting a snapshot of each VM to reset its CBT.

Is there any known problem with having two CBT-enabled backup solutions using VADP to backup the same VMs?

[soncscy]

I'm curious on this, as I've never seen such a thing.

Veeam in v10 resets CBT when it does an active full, but the way a backup app should work is that it just offers its last recorded change_id to Vmware and VMware returns all changed blocks.

I know from a lot of experience and cases with support Veeam does this -- does Arcserve? How do they handle CBT with VMware?

[Andreas Neufert]

Hi, multiple backup applications can use CBT without issue by design. If you end up in corrupt CBT files then it is usually something else. For example if a host loose power usually the CBT files are corrupt... or if you reduce the disks, the backup solution need to reset CBT... don’t know if the other backup application do this automatically. What is the actual error message?

[Vejete]

@Andreas we've no errors so far. Just wanted to ensure we weren't shooting ourselves in the foot before allowing the dual backup app situation to exist. Thank you kindly for your response!

[Andreas Neufert]

Change block tracking is no issue and is compatible for multi backup software approach.

Be carefull to not process VMs at same time to avoid VSS errors. Veeam would run into automatic retry if consistency can not created.

Most important thing here is that you do not backup your database logfiles in a way that they are only partly on both solutions. Then non of the solution can restore to point in time.