US Patent 7519858 Selective file restoration from incremental backups

According to one embodiment, providing application information includes receiving a request for application information associated with a checkpoint. A checkpoint corresponds to an incremental backup of a sequence of incremental backups of the application information. The following is performed for each logical block of one or more logical blocks that store the application information: establish whether any incremental backup records a change for a logical block; process the request using an incremental backup if the incremental backup records a change for the logical block; and process the request using a full backup of the application information if no incremental backup records a change for the logical block.