US Patent 10146630 Block changes framework for delta file incremental backup

Embodiments are directed to a method of performing incremental block based backups for volume and sub-file level backups by providing a change block tracking driver component, maintaining a context of the change block tracking driver as a driver context using a single bitmap that represents the volume being tracked, and maintaining the bitmap as the only element to track changes across the volume backups and multiple application backups involving different sub-file level backups.