Changed Block Tracking for Image-Based Backups

Changed Block Tracking is an algorithm that reduces source data reading during incremental image-based backups.

How It Works

Once the first full backup is made, each MFT (Master File Table) is marked. On subsequent incremental backup runs, the MFT is read again and blocks are compared. If a block is modified, the changed block tracking mechanism determines which files have been modified and locates disk clusters that contain file data.

Once all blocks are compared, only modified blocks are sent for reading.

As a result, the changed block tracking algorithm reduces the amount of data processed when reading a disk, which significantly reduces the backup time.