This option is effective for disk-level backups of virtual machines and of physical machines running Windows. It is also effective for backups of Microsoft SQL Server databases and Microsoft Exchange Server databases.
The preset is: Enabled.
This option determines whether to use Changed Block Tracking (CBT) when performing an incremental or differential backup.
The CBT technology accelerates the backup process. Changes to the disk or database content are continuously tracked at the block level. When a backup starts, the changes can be immediately saved to the backup.