PowerProtect Data Manager 19.11 Virtual Machine User Guide

Enable or disable Changed Block Tracking (CBT)

The Changed Block Tracking (CBT) feature is used to identify areas of the virtual-machine backup that have changed since the last backup and only process those changed areas during the next backup. CBT is enabled by default.

1. From the PowerProtect Data Manager UI, select Infrastructure > Assets.
2. From the Assets window, select the Virtual Machine tab.
   If a policy has been assigned, the virtual-machine assets that have been discovered in the vCenter server display, along with the associated protection policy.
3. Select one or more virtual-machine assets from the list, and click More Actions > Changed Block Tracking.
   The Changed Block Tracking dialog box appears.
4. Clear the check box to disable CBT, or select the check box to enable CBT.
   If there are high change rates on the virtual machine, CBT can sometimes cause backups to take longer than expected. If the backups are taking too long to complete, you can disable CBT for virtual machines. Also, if you encounter an issue with CBT, you can disable it on the virtual machine.

   NOTE If CBT is enabled in PowerProtect Data Manager but is disabled in VMware vSphere, PowerProtect Data Manager tries to back up the virtual machine with CBT enabled. If PowerProtect Data Manager cannot enable CBT, the backup completes with a warning that indicates CBT data is not available.
5. Click Save.
   NOTE When CBT is disabled for a virtual machine, subsequent backups no longer use CBT.