摘要 |
A primary data storage subsystem has primary data storage and a storage controller for controlling access of host processors to the primary data storage. The primary data storage subsystem is linked to a secondary data storage subsystem for transfer of backup data between the primary data storage subsystem and the secondary data storage subsystem. The secondary data storage subsystem has a tape library unit for storing the backup data. A host processor usually accesses the primary storage. A host can also send backup and restore commands to the storage controller, to cause specified data from the primary storage to be written as a backup version in the tape library unit, and to cause a specified backup version to be read from the tape library unit to be accessible to the host from the primary data storage unit. In this fashion, the host need not be concerned with the basic operations of the tape library unit. A host, however, can send backup media remote control requests to the storage controller, and the storage controller responds by sending corresponding backup media remote control commands to the tape library unit, to permit the host to control remotely the basic operations of the tape library unit. Therefore, the host can obtain status of read/write stations in the tape library unit, and control the mounting, unmounting, and transport of the tapes mounted at the read/write stations.
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