When a tape library is partitioned, each tape drive may be online in only one sysplex. If the sysplex does not have JES3 or equivalent support for the sharing of tape drives, the tape drive may be online to only one system within the sysplex. A tape drive may be switched from one sysplex to another by varying the drive offline in the old sysplex and then varying it online in the new sysplex.

To provide optimum tape library performance, first determine which TCDBplex is to own the cartridges in the cartridge loader. For the systems associated with that TCDBplex, use the LIBRARY SETCL command to associate the cartridge loader with a particular media type or ANY (this must be done on each system). To ensure that the other non-owning TCDBplex systems don't attempt to index another system's cartridges, use the LIBRARY SETCL command on those systems to set the cartridge loader to NONE. Also by default, after an IPL the cartridge loader will be set to NONE. See Displaying the cartridge loader scratch media type, and Setting the cartridge loader scratch media type for more information.