Tape operator
The operator to whom the task of tape processing has been assigned, is the “tape operator”. The tape operator performs the following tasks:
- Assigning the real tape devices to the BS2000 systems:
BS2000 offers the ATTACH-DEVICE and DETACH-DEVICE commands (I/O reconfiguration) to attach or detach devices to or from systems. - Processing tape requests in accordance with the console messages:
- mounting and dismounting tapes;
- dealing with error situations reported at the console.
- Updating tape management, e.g.:
- which user is using or has released which tapes;
- which tapes are in the scratch pool;
- at which location is a tape kept.
Mounting tapes
When BS2000 encounters a request for a tape (e.g. within a file processing command), it informs the operator that the tape has to be mounted on an available tape device. The request waits for the operator to inform BS2000 of the device name (mnemonic) of the tape device on which the tape has been mounted.
Since the BS2000 system automatically recognizes any available tape devices in its configuration, it can propose a tape device on which to mount the tape. However, the operator may choose to use a different tape device. The BS2000 system also recognizes tapes that have already been mounted.
Operator console
Any tape requests from the BS2000 system are issued to the console in the form of console messages that may or may not require a response. The console is the central location for operating the tapes and tape drives. The operator is informed via a tape request on this tape device and responds to the message when the request has been dealt with.
Locations
All tapes (with the exception of the tapes currently mounted) are stored in the data center at specific locations (see section “Location of the tapes” (Organization of tape inventories in the data center)).
When a tape is requested, the operator must fetch it from its location.
Tapes that are used for long-term archiving will seldom be mounted again and may be kept at some more remote location. For backups of crucial importance to a company, the tapes are often stored in a fireproof room (fireproof archive).
Request for a specific tape
BS2000 implicitly requests a tape to be mounted when the user requests data storage to tape. The tapes are identified by their archive number.
The archive number is assigned by the user who started the job.
The operator has to react to this explicit tape request by retrieving the tape with the specified archive number from its current location and mounting it in a free tape device.
Requesting any free tape (scratch request)
BS2000 also supports requests for tapes whose archive number is specified neither by the user nor by the application. In this case the tape operator has to select the tape.
If tape operators receive a mount request without an archive number (keyword *SCRATCH) they have to select an tape from their pool. In this case they must bear in mind that the tape selected contains no data which is already being used by another application. In other words, they search for a free tape in a set of scratch tapes. When tape operators have chosen a tape which they intend to mount, they have to respond to the mount request by entering the tape’s archive number.
It is important for the operator to know which tapes are being used by applications and which not. If a large number of tapes are being managed, the operator needs to keep a list of all tapes being used in the data center.
Tape owners and access to data on tapes
In BS2000, data is normally separated on a user-specific basis.
When users write their data to a tape, they have to make sure that no other user can access the tape and the data it contains. A user remains owner of a tape until they release it again or until the expiration date is reached.
However, BS2000 does not contain data protection features referring to tape ownership, because tapes are not inseparably tied to a BS2000 system. They can be removed from it at any time, and can be accessed by any other BS2000 system, regardless of who owns them.
Protection must be implemented by the operator. When a tape is written by the application of a particular user, the request for this tape by another user may not be granted. An exception exists when two or more users agree to share the tape. The tape operator or the tape administrator needs to be informed of the decision. The operator has to change the ownership information in the utilization list that the operator should keep.
Tape administrator
The tape administrator works under a BS2000 user ID with the privilege TAPE-ADMINISTRATION. The tape administrator is responsible for managing the tapes in a data center. The tape administrator is responsible for supplying the data center with all tapes required for day-to-day work.
The administrator’s tasks comprise:
- initializing new tapes;
- returning tapes which are no longer required to the scratch pool (after the tape user has been informed). Before the tapes are used again, the recorded data should be deleted;
- reinitializing tapes, if necessary, when tapes are released and returned to the scratch pool;
- discarding defective tapes;
- keeping track of tapes received from a remote data center or of tapes sent to a remote data center;
- creating and updating a list containing the following information:
- Which tapes exist in the data center?
- Where is which tape kept (location)?
- Which user is using which tapes?
- Is a user sharing tapes with other users?
- Until when does a user need his/her tapes?
- Which tapes are allotted to the scratch pool?
This list is drawn up by the tape administrator and updated by the operator when the tapes are mounted or dismounted.
- organizing secure tape operation (access control).