Abstract: An apparatus and method for mirroring data is provided wherein integrity of data on a mirror device is maintained during and after a restore process of data to a standard volume. Because integrity of the mirror is maintained, data from the mirror may be used to perform a later restore to the standard volume if data becomes corrupted, or data is unavailable for any other reason. As a result, the mirror may be used for backup or other operations.

Abstract: A backup server controls the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies. The backup server comprises a discovery module, a preparation module, an execution module and a clean-up module. The discovery module receives the backup request and identifies, during a discovery phase, at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored. The preparation module, during a preparation phase following the discovery phase, enables the mass storage subsystem to sever one of said mirrored copies and make it available to backup server for the backup operation.

Abstract: A backup server controls the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies. The backup server comprises a discovery module, a preparation module, an execution module and a clean-up module. The discovery module receives the backup request and identifies, during a discovery phase, at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored. The preparation module, during a preparation phase following the discovery phase, enables the mass storage subsystem to sever one of said mirrored copies and make it available to backup server for the backup operation.

Abstract: Method and apparatus for backing up and restoring data in a computer system is disclosed. A segment of data, such as a virtual disk partition, may be backed up at a physical level from a primary storage device to a backup storage device. A logical element within the segment of data, such as a data file, may be restored from the backup storage device to the primary storage device. In one embodiment, this is achieved by restoring the segment to a scratch memory area and using a client computer to logically restore the logical element.