US Patent 8099391 Incremental and differential backups of virtual machine files

Various embodiments of a system and method for backing up files used by a virtual machine are described herein. The files may be stored within a virtual disk image file. A full backup of the virtual disk image file may first be created. After creating the full backup, one or more incremental or differential backups of the virtual disk image file may be created. In some embodiments, fingerprints of the sectors of the virtual disk image file may be stored and used to identify which sectors should be included in the incremental or differential backups.