Error: Change Block Tracking not enabled on <disk> (4047462)

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 hav been shown to cause this error, although not in all cases:

• ESX host crash
• VMX 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, than re-attached
• HotAdd

Workaround 1:

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

1. Remove snapshot from the VM
2. Disable CBT
3. Enable CBT
4. Take snapshot

Workaround 2:

In some cases, deleting the *.ctk.vmdk file for each disk in the affected VM has been shown to resolve this issue.