Block-level backup is a faster method to back up data because only the extents that contain data are backed up, rather than the entire files.
Block-level backups provide better performance over file system backups and disk image-based backups if the file system has a large number of small files by reducing the scan times. Also, when compared to file system incremental backups, block-level incremental backups run faster and back up less data if the file system has very large files. Block-level backups might not be useful when backing up a portion of files or folders on a volume.
By default, block-level backups are performed using native snaps, but they can be configured to function with hardware snap engines.