Modified Block Tracking for Image-Based Backups
Modified Block Tracking is an algorithm that features a decrease in source data reading on incremental image-based backups.
How It Works
Each time an image-based backup plan runs, the state of the blocks at the moment a backup plan start is saved.
Once a first full backup is made, each MFT (Master File Table) is marked. On subsequent incremental backup runs, MFT is read again and blocks are compared. If a block is modified, a modified block tracking algorithm 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 modified block tracking algorithm reduces the processed data amount when reading a disk, which significantly reduces the backup time.
The modified block tracking algorithm is supported by NTFS file systems only