To remove a set of logical volumes from a VTS, the operator or the tape management system should first run a vaulting-type operation at the host to determine the list of logical volumes to be exported. This list is then written in volume serial number and destination pairs as the first file on an available logical volume. This volume then becomes the export list volume. This export list volume must reside in the library where the volumes to be exported reside and it must be written in a library specified format. Two more files are also written on this export list volume. File sequence two is a file reserved for future use. File sequence three is written and later updated by the VTS to record the export status of each logical volume listed in the export list. All three files must be written in the library specified format.

See IBM TotalStorage Enterprise Automated Tape Library (3494) Operator’s Guide for details regarding the library specified format. See SAMPLIB member CBRSPSXP and SAMPLIB member CBRSPPXP for sample JCL that can be used to write the three required files on the export list volume. The DFSMSrmm SEARCHVOLUME command with the CLIST option can be used to create this export list. For more information on this command, see z/OS DFSMSrmm Managing and Using Removable Media.

Once the export list volume is written, the LIBRARY EXPORT command or the CBRXLCS external programming interface FUNC=EXPORT can be used to identify the export list volume and to initiate the export operation at the library. For more information, see Export logical volumes (EXPORT) and Exporting logical volumes from a VTS. Only one export operation can be queued or in progress at a time in each VTS system. Also, if an import is currently queued or in progress, an export operation cannot be initiated to the same VTS system.

The library then mounts the export list volume and determines the list of volumes to export and either the destination or destinations for the logical volumes. Logical volumes with the same destination will be grouped together on the same stacked media. This lets a single export operation cover multiple destination sites. The library then begins writing the export logicals on stacked volumes. If the VTS has outboard policy management support, the volume's policy names are included on the stacked volume. On the third file of the export list volume, the library records the status of each logical volume being exported; this can be referred to as the export status file. If a volume cannot be exported because it is currently in use or does not exist in the library, the export status file indicates the error that occurred, as well as reflects the successful export of each logical volume. Each exported stacked volume contains a volume map identifying the contents of the stacked volume, logical volume data fragment files for each logical volume successfully copied, and the logical volumes themselves. A single export operation may result in many stacked volumes being exported with multiple volumes per destination.

As the library manager finishes with a stacked volume, the logical volumes are assigned to the exported category. The volumes in this category are then processed by OAM. Volume export processing is similar to eject processing; however, in addition, the cartridge eject installation exit (CBRUXEJC) is passed the container volume serial number of the stacked cartridge on which the logical volume resides. This is information that the tape management system will want to record. The tape management system’s acceptance of the eject is implicit (there is no opportunity to fail the eject). However, in an environment where a common TCDB is shared by more than one tape management system and each tape management system has its own database, the tape management system can return UXJIGNOR, Return Code 12, to allow another tape management system who “owns” the exported volume to process. If UXJIGNOR is returned from the CBRUXEJC installation exit, the logical volume remains in the exported category; otherwise, each logical volume is then purged from the library manager inventory and the host TCDB volume record is kept or purged, depending on the disposition specified by the installation exit or defaults set for the library when it was defined using ISMF.

Once all logical volumes residing on a stacked cartridge have been successfully purged from the library manager inventory, the export operation continues at the library, filling another stacked volume for the destination currently being processed. The completed stacked cartridge can then be released by an operator at the library manager either on an individual completion basis, or after a set of volumes has been processed. For the export operation to continue with minimal host delays, it is important for a host that owns the TCDB records for the logical volumes being exported to have the OAM address space available to process the volumes in the exported category. This enables the exported category to be processed without delays and allows the library to continue with the next stacked volume.

Once the export operation is complete, all hosts attached to the VTS system that performed the operation are notified of this completion. This enables export completion status to be reported independently of the status of the host that initiated the export operation. If the attached host has the export list volume in its TCDB, messages are issued with the completion results of the export operation. Status messages are also issued at key processing points throughout the export operation. See Export status messages for more information.