MAREN permits the reading and writing of a tape only when the tape has been reserved for a user ID in the MAREN catalog. The tapes in the HSMS/ARCHIVE free tape pool are not reserved, but they are “prereserved”. This means a tape from a HSMS/ARCHIVE free tape pool must first be reserved for the requesting user ID, before actual processing can be carried out. This reservation can be implemented either implicitly by means of automatic free tape allocation with MARENUCP or explicitly using the statement below.
HSMS:
//MODIFY-ARCHIVE ARCHIVE-NAME=..., VOLUMES=*ADD(VOLUMES=...)
ARCHIVE:
*POOL DIRECTORY=...,ADD=(<vsn>,...)
Implicit reservation
In a data center with MAREN, it is advisable to leave the administration of the free HSMS/ARCHIVE tapes to MAREN and to keep only the written tapes in the directories. This mode of operation is automatically applied when there are no available archive numbers in the directory.
The existing save jobs need not be altered to reserve additional tapes, because if the pool is empty all the required archive numbers will be requested from the operator with the HSMS statement //BACKUP-FILES .. VOLUMES=*FROM-POOL or the ARCHIVE statement *SAVE...,TAPES=POOL. The VOLUMES=*OPERATOR (HSMS) or TAPES=OPERATOR (ARCHIVE) operand does not need to be specified.
If a free tape is requested for an HSMS/ARCHIVE application, MARENUCP determines the archive number of an appropriate free tape and reserves this tape in the MAREN catalog for the requesting user ID.
The HSMS/ARCHIVE free tape pool from which the tape is then assigned depends both on the type of request and the existence of the individual pools. This is determined by the following criteria, which are applied in the following order:
If a directory is being used and a free tape pool exists for this directory, the tape will be assigned from this pool.
If the request is output from TSOS or if the directory is cataloged under TSOS and a free tape pool for TSOS exists, the request is satisfied from this pool.
If a pool for general HSMS/ARCHIVE applications (
FREE-POOL=*GLOBAL) exists or if the directory is not cataloged under TSOS, the request is satisfied from this pool.If there is no suitable pool, the tape will be assigned from the general free tape pool in MAREN.
The free tape pool can also be determined via a reservation file, see “Example 7: Allocating the free tape pool *TSOS” (Examples). If a reservation file is used, the rules 1-4 mentioned before do not apply.
If a pool empties during a session, MARENUCP does not automatically use another pool but addresses the operating. The operator must then take the appropriate steps according to how the data center is organized. Until the appropriate steps are taken, all the HSMS/ARCHIVE tasks are suspended.
Location
In HSMS/ARCHIVE, archive numbers can be requested from a specific location using the LOCATION operand in the BACKUP-FILES statement (HSMS) or in the SAVE statement (ARCHIVE).
If the MAREN administrator assigns tapes from a different location to the user by means of a MAREN exit, the specification of the user is ignored.
If the MAREN administrator assigns the user tapes from a different location using the MAREN Location Manager, the system-specific MAREN parameter OVERRULE-LOC decides on the further procedure:
OVERRULE-LOC=REJECT: the location specified by the user is used (differing locations lead to the reservation being rejected)
OVERRULE-LOC=YES: the location specified in the MARENLM is used
Explicit reservation
The HSMS statement //MODIFY-ARCHIVE ... VOLUMES=*ADD(...) or the ARCHIVE statement POOL DIRECTORY=...,ADD=(<vsn>,...) can be used to explicitly reserve prereserved tapes from the HSMS/ARCHIVE free tape pool in the MAREN catalog. These tapes are then allocated to the specified user ID in the MAREN catalog and entered in the directory as freely available archive numbers. This explicit reservation is not generally logical or necessary, but is nonetheless supported for reasons of compatibility or for unique situation. When using this type of reservation the given sequence for implicit reservation is compulsory. For example, if a free tape pool exists for a particular directory, only tapes from this pool can be reserved for the specified directory.
Special considerations for explicit reservation:
The tape is prereserved for HSMS/ARCHIVE in the MAREN catalog, but not in an appropriate subset (e.g. prereserved for another directory name). In this case the ARCHIVE statement POOL is rejected with the corresponding error message.
The tape is entered in the MAREN catalog as a “reserved tape in the local data center”. The statement is only accepted if the tape has already been assigned to the user’s own ID, it is not contained in a directory, and it has previously not been reserved for the user ID in a HSMS/ARCHIVE save run via the automatic free tape allocation. The statement is also rejected if a special free tape pool exists for this directory.
The tape is entered in the MAREN catalog as a “reserved tape from a remote data center”. This statement is only accepted if the tape has been assigned to its own user ID in the MAREN catalog and has not yet been included in a directory for which there is also no special free tape pool.
The tape is not contained in the MAREN catalog. If it is permitted for tapes not contained in the MAREN catalog to be processed using the MAREN parameter
FOREIGN-TAPE-CHECK=NO, the tapes will be included in the directory; if not, they are rejected.If the archive number of a free tape is specified in the context of an HSMS/ARCHIVE save run (e.g. in the case of HSMS
//BACKUP-FILES .. VOLUMES=<vsn>or ARCHIVE*SAVE ..., TAPES=<vsn>), this tape is also reserved, provided it is assigned to an appropriate HSMS/ARCHIVE free tape pool.