NVP vProxy: VM backup completes successfully but with the warning "Virtual Machine does not have Change Block Tracking Enabled"

A NetWorker VMware Protection (NVP) policy completes successfully but reports warnings.
The VM backup session logs report:

YYYY-MM-DDTHH:mm:SSZ INFO:   [@(#) Build number: ##]       "Virtual Machine does not have Change Block Tracking enabled, cannot perform incremental backup, reverting to full copy of virtual disks.",
YYYY-MM-DDTHH:mm:SSZ INFO:   [@(#) Build number: ##]       "CBT data not available: Synthesizing used block list to cover entire logical disk."

The VM session log can be reviewed from the following locations:

• From the NetWorker Management Console, open the backup action details from the Monitoring window. Click the VM that completed with the warning under "completed successfully." With the VM selected, click Show Messages, then click Get Full Log.
• On the NetWorker server, in the policy logs directory:
  • Linux: /nsr/logs/policy/Policy_Name/Workflow_Name
  • Windows: C:\Program Files\EMC NetWorker\nsr\logs\policy\Policy_Name\Workflow_Name
• The vProxy session logs:
  • /opt/emc/vproxy/runtime/logs/recycle/vbackupd/Date

nsr-vproxy01:/opt/emc/vproxy/runtime/logs # grep -rnw /opt/emc/vproxy/runtime/logs/recycle/vbackupd/20240717_1/*.log -e "cannot perform incremental backup"
/opt/emc/vproxy/runtime/logs/recycle/vbackupd/20240717_1/BackupVmSessions-8e64fa68-2cdb-49a3-9e18-6ec01f7040cf.log:408:2024-07-17T16:00:29Z WARN:   [@(#) Build number: ##] Virtual Machine does not have Change Block Tracking enabled, cannot perform incremental backup, reverting to full copy of virtual disks.
...

To perform incremental backups of the VM, the VMware administrator must perform the following actions on the VMs reporting this warning.

1. Power off the VM.
2. Right-click the VM and select Edit Settings.
3. Go to the Advanced Parameters tab.
4. Set the following parameters:

5. Power on the VM.

For more information, see the following VMware KB: Enabling or disabling Changed Block Tracking (CBT) on virtual machines

After these changes, the next incremental backup should use CBT and transfer only blocks changed since the last backup.
 

NOTE: The NetWorker Management Console (NMC), and media database (mminfo) always shows the VM backup as level full. Backup levels and reporting can be analyzed further following NVP vProxy: Understanding VMware VM backup levels shown in NetWorker.