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, assign one of the scratch media types to be preloaded into the integrated cartridge loader (ICL) on each 3495 library-resident tape drive. Varying the drive offline in one place and then online in another place does not change which media type has been assigned to the ICL. If the drive is now online in a different sysplex, the category for the preloaded scratch media type is not one that is defined in the new sysplex. A LIBRARY DISPCL or DISPDRV command displays the category as currently assigned. As part of switching the device to the new sysplex, the operator should use LIBRARY SETCL to assign the scratch media type; this causes the assignment of a category that is defined in the new sysplex. In response to the command, the Library Manager unloads the cartridges that are currently in the ICL and replaces them with cartridges from the scratch category in the new sysplex. See Displaying the cartridge loader scratch media type, and Setting the cartridge loader scratch media type for more information.