Change Block Tracking not enabled on <disk> (4047478)

When performing full backups with CBT enabled, the CBT operation may fail with error " Change Block Tracking not enabled on <disk>". When performing incremental or differential backups of the same VMs, CBT will function properly.

The following scenarios have been shown to cause this error, although not in all cases:

• ESX host crash
• Storage vMotion of the VM (while powered off)
• Changes in the VM disk configuration that cause the disk device key to change
• A disk was detached from the VM, then re-attached

Workaround 1:

In some cases, performing the following operation has resolved this issue.

1. In the My Inventory section, right click the VM and select Disable CBT
2. Locate the VM in the vSphere Client and take and remove a snapshot on the VM
3. Go back to the My Inventory section in vRanger and Enable CBT
4. Locate the VM in the vSphere Client and take and remove a snapshot on the VM

• The VM must go through a stun/unstun cycle to activate changed block tracking