RESTORE OF FULL SYSTEM BACKUP AND INCREMENTAL BACKUPS USING MULTIPLE SIMULTANEOUS DEVICE STREAMS

摘要

A technique for restoring file systems by applying full and incremental backups together while streaming them from multiple devices provides a faster system restore from a full backup where incremental backups must also be applied. A first storage device streams the full backup while at least one second storage device streams at least one incremental backup. As files are detected in the incremental backup, they are written instead of the corresponding file in the full backup. Incremental backups can be pre-merged to reduce their number to one less than a number of storage devices available to stream the backups, so that the full backup can be streamed along with the pre-merged incremental backup(s) to restore the file system.

主权项

1. A computer-performed method for restoring a file system to a target storage, the method comprising:
first reading a first backup stream containing a full backup of the file system from a first one of multiple storage devices; while performing the first reading, second reading at least one second backup stream containing a corresponding at least one incremental backup of the file system from a corresponding at least one second one of the multiple storage devices; prior to completing the first reading of the full backup and prior to completing the second reading of the at least one second backup, determining whether the at least one second backup stream contains a copy of a file read by the first reading; responsive to determining that the at least one second backup stream does not contain the copy of the file read by the first reading and prior to completing the first reading of the full backup and prior to completing the second reading of the at least one second backup, first writing the file read by the first reading to the target storage; and responsive to determining that the at least one second backup stream contains the copy of the file read by the first reading and prior to completing the first reading of the full backup and prior to completing the second reading of the at least one second backup, second writing the file read by the second reading to the target storage.