Troubleshoot VM issues - AWS Backup

Troubleshoot VM issues

Incremental Backups / CBT issues and messages

Failure message: "The VMware Change Block Tracking (CBT) data was invalid during this backup, but the incremental backup was successfully completed with our proprietary change detection mechanism."

If this message continues, reset CBT as directed by VMware.

Message notes CBT was not turned on or was unavailable: "VMware Change Block Tracking (CBT) was not available for this virtual machine, but the incremental backup was successfully completed with our proprietary change mechanism."

Check to make sure CBT is turned on. To verify if a virtual disk has CBT enabled:

  1. Open the vSphere Client and select a powered-off virtual machine.

  2. Right-click the virtual machine and navigate to Edit Settings > Options > Advanced/General > Configuration Parameters.

  3. The option ctkEnabled needs to equal True.

If it is turned on, ensure you are using up-to-date VMware features. The host must be ESXi 4.0 or later and the virtual machine owning the disks to be tracked must be hardware version 7 or later.

If CBT is turned on (enabled) and the software and hardware are up to date, turn off the virtual machine and then turn it back on again. Ensure that CBT is turned on. Then, perform the backup again.