Using VMware's Changed Block Tracking for full backups only
This topic applies to NetBackup for VMware.
The option (BLIB) in the NetBackup VMware policy applies to full backups and incremental backups. BLIB skips blocks on the virtual disk that are unmodified since the last backup. If you want to skip unmodified blocks during full backups but not incrementals, do not configure the policy for BLIB. Instead, enable changed block tracking by means of the vSphere Client interface.
More information is available on BLIB.
See Block-level backup (BLIB): full vs incremental.
To enable changed block tracking for full backups only (vSphere Client interface)
In the vSphere Client interface, power off the virtual machine.
Select the virtual machine, then click .
Obtain the hard drive controller and disk numbers (SCSI and IDE) for each virtual drive on the virtual machine.
To find the controller number and disk numbers, do the following:
Click the Options tab. Under Advanced, General, click .
On the Configuration Parameters screen, click .
Enter ctkEnabled in the Name column and enter true for the .
For each virtual drive on the virtual machine, enter a in the form:
where X:X represents the controller number and disk number of each disk as found on the Hardware tab.
For example: scsi0:0.ctkEnabled for the first disk and scsi0:1.ctkEnabled for the second disk. (The numbers for your disks may be different.)
Enter true for the of each disk entry.
Power on the virtual machine.
Now you can use vSphere Client to take a snapshot of the virtual machine. NetBackup can apply vStorage optimization (changed block tracking) to future backups of the virtual machine.
See About reducing the size of VMware backups