VM Diff Backup / Changed Block Tracking

[astewart]

I have 35+ VM guest servers split between 6 ESXi 4.0 hosts. I can and have taken full backups of them via the vCenter-RRC without issue. I cannot seem take diff or incr backups of the VMs. I receive the 'Changed block tracking on VM required for this backup type." error. I have CBT enabled on the VMs, they're v7 VMs, and I've verified that vSphere has created the *-ctk.vmdk files. Am I missing something? (Obviously, I must be). I'm sure it's probably something simple and I'm just not seeing it.

Thanx
A

[vwsurfer]

If you look in your ESX servers' and vCenter MOBs do they agree and both say the change block tracking (CBT) is both enabled and supported? Also, are your VMs located on NFS datastores?

[astewart]

If you look in your ESX servers' and vCenter MOBs do they agree and both say the change block tracking (CBT) is both enabled and supported? Also, are your VMs located on NFS datastores?

It resolved itself. I moved VMs around to change the block size on the datastores, after I did that the Incr/Diff backups worked. It was likely something I was missing/forgetting and the VM moved triggered whatever it was.