To ensure that only one TCDBplex has access to any single tape volume, assign a separate range of volume serial numbers to each TCDBplex. Cartridge Entry Installation Exit (CBRUXENT) may be used to accept volume serial numbers in the range assigned to the TCDBplex when they are entered, but to ignore volume serial numbers that are outside the range. Each system in the TCDBplex must have the same installation exit. Each different TCDBplex must have installation exit logic that accepts a different range of volume serial numbers.
DFSMSrmm offers facilities (the PRTITION or the REJECT ANYUSE commands in PARMLIB member EDGRMMxx) that allows an installation to specify partitioning information for this TCDBplex. See DFSMSrmm support for sharing a tape library dataserver.