Abstract: The average time a user must wait to have an object retrieved from an automated optical disk library is reduced by a method for prioritizing read requests. When a read request is received it is added to a queue of pending requests. All pending requests associated with volumes currently mounted on optical disk drives are processed first. The pending requests associated with the opposite sides of the currently mounted volumes are processed next. The next requests to be processed are those pending read requests associated with the unmounted volume having the greatest number of pending read requests. Thereafter any other pending requests for that unmounted volume will be processed as normally would be done for a currently mounted volume. This method continues until all pending read requests have been processed for the unmounted volumes.

Abstract: The response time of an automated optical disk library is improved by writing object delete requests to a deleted objects table before actually physically deleting those objects. By collecting object delete requests in a list of pending deletes for each volume in the library the number of necessary mounts are reduced. The delete requests in a list of pending deletes for a given volume are physically deleted just prior to performing a write or defrag request for that volume. The list of pending deletes for that volume are then deleted from the deleted objects table. During idle periods a predetermined number of pending delete requests will be performed for the currently mounted volume. If there are no pending delete requests for the currently mounted volume then a predetermined number of pending delete requests will be performed on the opposite side of the currently mounted volume.

Abstract: A storage-management program, executable in one host or simultaneously in a plurality of hosts, manages concurrently executing migration, recall, and recycle (such as defragmentation) tasks. Accesses to data storage volumes (tape, disks, etc.) are managed in accordance with predetermined contention resolution procedures and priorities. Certain tasks are non-interruptible.

Abstract: A storage-management program, executable in one host or simultaneously in a plurality of hosts, manages concurrently executing migration, recall, and recycle (such as defragmentation) tasks. Accesses to data storage volumes (tape, disks, etc.) are managed in accordance with predetermined contention resolution procedures and priorities. Certain tasks are non-interruptible.