The storage locations of volumes are administered in MAREN (see the “MAREN” manual [10]). MAREN logs all the storage locations of the volumes. Whenever a volume is moved to another location, the corresponding entry in the MAREN catalog must be updated. The following input fields are concerned here:
TEMPORARY-LOCATION: current location of the volume
HOME-LOCATION: permanent location of the volume
A device pool management concept was developed in Nucleus Device Management (NDM) primarily in order to support robot-controlled archives in BS2000 (software product “ROBAR”). In conjunction with MAREN, this device pool management enables users to select specific devices for processing tape volumes. The ADD-DEVICE-DEPOT command is used to assign tape units to storage locations. However, the locations must be made public in MAREN beforehand by the system administrator and they must tally with those specified by the operator.
The SECURE-RESOURCE-ALLOCATION command can be used to reserve a tape unit for a certain location. If HSMS requires a magnetic tape cartridge for a read or write operation, a /SECURE-RESOURCE-ALLOCATION command is issued internally with the specified storage location. The following restrictions apply:
The devices are requested with the specified storage location or that defined in the archive. If the volumes are also specified, these must be assigned to the specified storage location.
If HSMS knows no storage location but only the volumes, the location of the volumes is determined using MAREN.
/SECURE-RESOURCE-ALLOCATION is issued for every input data volume required for any of the HSMS statements RESTORE-FILES, IMPORT-FILES and RECALL-MIGRATED-FILES. The wait time corresponds to the specification defined with the HSMS parameter DIALOG-REQUEST-TIME or BATCH-REQUEST-TIME.
The following applies to other activities (BACKUP-FILES, BACKUP-NODE-FILES, ARCHIVE-FILES, ARCHIVE-NODE-FILES, MIGRATE-FILES, EXPORT-FILES, COPY-SAVE-FILE, COPY-NODE-SAVE-FILE, COPY-EXPORT-SAVE-FILE, UPDATE-EXPORT-SAVE-FILE):
/SECURE-RESOURCE-ALLOCATION is issued once for the output device having the same storage location as the output data volume. The assumption is that all subsequent data volumes are available at the same location.
/SECURE-RESOURCE-ALLOCATION is issued every time duplication of a save version commences. The assumption is that all data volumes belonging to a save version are available at the same storage location (i.e. that the user has not changed the storage location in the MAREN catalog).
If no storage location is defined in the system, /SECURE-RESOURCE-ALLOCATION is issued without specification of a storage location. If at least one storage location is specified, HSMS assumes that all the storage locations entered in the input fields of the MAREN catalog correspond to a valid storage location. If this is incorrect, it causes an error and in some cases it can even lead to an abort.
If a task has already been assigned an output device and this task requests a new output tape from MAREN, then MAREN can take control of the output device. In this way, MAREN can – if necessary – initialize the newly requested output tape. Following initialization, the output device is returned to the task in question so that this can continue processing.
ARCHIVE does not support tape initialization with //COPY-SAVE-FILE or //COPY-NODE-SAVE-FILE with SAVE-FILE=*NEW(...). In this case, ARCHIVE attempts to use the tape without initializing it. If, despite this, tape initialization is demanded, MAREN rejects the tape.