Information on automatic free tape allocation

When allocating a free tape, the catalog entry fields listed in the table below are set. All other catalog entry fields are set immediately after the free tape is assigned during OPEN processing.

Catalog entry field	Catalog entry field values subsequent to allocation
USER-IDENTIFICATION ACCOUNT CREATION-JOB-NAME	The user ID, account number, and job name are taken from the user's SET-LOGON-PARAMETERS command. In the case of HSMS tasks, the user ID of the HSMS directory and the first account number of the user entry are used. In the case of SPOOL output, the account number is filled with blanks.
FILE-NAME or DIRECTORY-NAME	The file name or directory name specified by the user is used.
USER-ACCESS	As set by the MAREN administrator.
RESERVATION-DATE	Current date.
FREE-DATE	The release date is determined from the value set by the MAREN administrator for DEFAULT-FREE-DATE.
DEVICE-TYPE	The value set by the MAREN administrator for DEFAULT-DEVICE-TYPE is used as the device type.
HOME-LOCATION	The value set by the MAREN administrator for DEFAULT-HOME-LOCATION is used.

Notes for the operator

• The prompt MOUNT TAPE <vsn> is output as messages which must be acknowledged under the user's TSN. You can use the SHOW-PENDING-MSG command to output any messages that have not yet been acknowledged. Messages can be rejected with tsn.N.
• The assignment of free tapes on real drives is accelerated if MARENUCP finds free tapes on the tape devices. It consequently makes sense to mount free tapes on free real tape devices as a precautionary measure. In an archive system, this task is performed by the archive controller. The provision of free tapes which are to be mounted in advance or as a result of a MARENUCP request can be handled by means of the MARENADM statement SECURE-FREE-VOLUME ...,USAGE=*BY-MARENUCP. This ensures that these tapes will be available to MARENUCP alone and cannot be explicitly reserved by users by means of the MAREN statement RESERVE-FREE-VOLUME.

  The MARENADM statement SHOW-FREE-VOLUMES USAGE=*BY-MARENUCP can be used to display the tapes which have been readied.

• A prerequisite for the automatic tape allocation facility is that the mount parameters for tapes include the operand ALLOCATE-TAPE=*YES (see the MODIFY-MOUNT-PARAMETER command). Otherwise, the user will have to acknowledge PREMOUNT messages for tapes that have already been mounted. The current settings for the mount parameters can be queried using the SHOW-MOUNT-PARAMETER command.

Notes for the MAREN administrator

• Free tapes to be assigned by the automatic free tape allocation facility must contain standard labels and must not be protected. The tapes have to be initialized before they can be used (again).

  This is achieved during MAREN operation either by specifying an output file (INIT-FILE) in the MARENADM statement FREE-VOLUMES when releasing reserved tapes and processing this file, or by means of the function for automatically initializing magnetic tapes (see "Automatic initialization of tapes").

  For tapes which are newly added to the MAREN, the MAREN administrator must ensure that these conditions are satisfied.

• If the cataog entries of tapes already mounted in tape devices are modified, any changes made generally do not come into effect for MARENUCP until the message NKVT011 is output after dismounting

Special situations

When errors occur in MAREN, MARENUCP terminates and issues error messages to this effect. In most cases, the other components of MAREN will also be affected. MARENUCP must be restarted after the error, whereupon it processes all open requests.

Changes to the input/output configuration implemented by means of dynamic reconfiguration are not detected automatically by the active MARENUCP task. To ensure that these changes come into effect, you must terminate and restart MARENUCP. This applies in particular if automatic initialization is used and new devices or device types have been added to the configuration dynamically.

Free tape allocation with FDDRL

See section “Allocation of free tapes” (FDDRL).