I assume you have the 6 LPARs set up each with their own fiber tape card going to a fiber san switch and each system is zoned in that san switch to have system A, tape 1, 2, 3, 4 then system B, tape 1, 2, 3, 4 then system C tape 1, 2, ,3 4 and so on.
If you are using the tape drive TAP01, TAP02, TAP03, TAP04 and not the tape library in BRMS then you will have to maually vary one at a time to each LPAR you want to use. You need to configure BRMS to use the tape library and then each tape drive will show up under the tape library TAPMLB01 with device TAP01, TAP02, TAP03 and TAP04 as Unprotected for the status. In my case my TAPMLB01 is called TAPLTO because we renamed it to distinquish it from the 3570 tape library that we had in place before.
This will allow BRMS ot look at each drive and determine if it is in use, it will move on to the next one under that library. This works great in our environment which sounds similar.
Work with Media Library Status
Type options, press Enter.
1=Vary on 2=Vary off 3=Reset resource 4=Allocate resource
5=Allocate unprotected 6=Deallocate resource 8=Work with description
Opt Resource Status Allocation name
TAPLTO VARIED ON
TAP08 OPERATIONAL UNPROTECTED
TAP09 OPERATIONAL UNPROTECTED
TAP10 OPERATIONAL UNPROTECTED
TAP11 OPERATIONAL UNPROTECTED
TAP3570LIB VARIED OFF
Parameters or command
F3=Exit F4=Prompt F5=Refresh F9=Retrieve F12=Cancel F17=Position to
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