Abstract: Clients are connected via a LAN to backup apparatus including hard and tape drives, respectively primary and secondary backups. Each client schedules backup operations on a time basis since last backup, the amount of information generated since last backup, etc. Prior to a backup, each client sends to the backup apparatus a request including information representing the files to be backed up. The backup apparatus receives backup requests from the clients and accepts or rejects backup requests based on backup and network loading. The backup apparatus eliminates redundant files and indicates to the clients, prior to the file back up, that some files requested to be backed up are already stored and are not to be sent. The backup apparatus enables a client to restore any of its ‘lost’ data by copying it directly from the disk, without the need for backup administrator assistance.

Abstract: Diagnostic data in a sequential access Small Computer System Interface device is accessed by a first logical unit. A second logical unit is configurable to control a mode of operation of the first logical unit. The first unit Provides normal and/or backup functions while the second unit provides diagnostic/status functions or the second unit activates the first unit to be online or offline, depending on the first unit being commanded to perform the diagnostic function.