The activities to be performed by the tape operator and tape administrator depend on the size of the data center. The response time to tape request is a performance factor in the administration of a data center.
When a large number of tapes needs to be managed and processed, this requires automation of the operator and administrator functions.
Magazines
Tapes are combined to form tape magazines. The operator inserts the tapes in a magazine before starting an application. So several tapes are available for mounting with no operator intervention needed when a tape is requested.
Tape magazines function in two different modes:
- Sequential mode:
The tapes are used one after the other to execute the BS2000 system’s tape requests. This mode is generally used for scratch tapes. - Direct mode:
The tapes are used as they are requested:- the application requests a specific tape in the magazine;
- the device locates the tape and mounts it.
As long as one tape is mounted, no other tape in the magazine can be mounted elsewhere.
Tape archive systems
An automated tape archive system (synonym: robot system, archive system for short) comprises a number of tape devices and tapes in a defined local area. For the outside world, it thus forms a self-contained unit. The tape devices installed within the archive system can only be mounted with the tapes contained in that archive system.
Archive systems automatically mount and unmount tapes from the archive system following a request by BS2000.
The archive system is also the location of the tapes.
The tape operator equips the archive system with tapes.
The archive systems used for BS2000 are the virtual archive system ETERNUS CS from FUJITSU and the real archive systems from Quantum Corp.
Automatic tape operator
The archive system replaces the human tape operator in fulfilling mount requests. It is either directly linked with BS2000 or through the interfaces of its tape devices or via its archive system, and it evaluates the messages on the console.
Automatic tape management with MAREN
The list mentioned on "Manual operation of real tapes" which contains information on the tapes in the data center can be automated with a tape catalog.
The software product MAREN offers various management functions when this is the case. All information on the managed tapes is recorded in the MAREN catalog. The data center tapes are added to the MAREN catalog together with their links and attributes. The information can be modified and deleted.
MAREN supports the tape administrator in his/her management tasks concerning:
- initialization;
- ownership and shared use;
- transport to various locations;
- sending tapes to or receiving them from other data centers;
- reservations;
- release and expiry;
- scratch pool;
- logging;
- statistical records.
MAREN works together with BS2000 to enable the useful life and the state of the tapes to be traced, and it is informed of tape requests and utilization through system interfaces.
Automatic response to scratch requests
Allocating free tapes when scratch tapes are requested can also be automated when an archive system and MAREN are used. In the case of a scratch request, MAREN determines a tape in the free tape pool that meets the reservation requirements (e.g. for the volume type) and supplies its archive number to the requesting application.