Allowing DFSMShsm to use the 3590-1 generic unit when it contains mixed track technology drives

You might encounter a situation in which you need to use the 3590-1 generic unit when it contains a mixture of 3590 devices that cannot share tapes. If so, you must use other means, such as SMS ACS routines, to keep these drives separate, and you can use this patch to disable the DFSMShsm compatibility checking:

PATCH .MCVT.+3D5 BITS(.1......)

You can use this patch to re-enable the DFSMShsm compatibility checking:

PATCH .MCVT.+3D5 BITS(.0......)

By default, checking is enabled for non-SMS tape allocations.

A non-SMS tape allocation for a generic unit 3590-1 containing mixed track technologies causes DFSMS to issue message ARC0030I. Here, DFSMShsm allows the allocation to continue, but a tape/tape unit mismatch can result in an OPEN failure.

DFSMShsm does not issue message ARC0030I for a mix of 3592-1, 3592-2, and 3592-2E tape units, nor for a mix of 3592-2, 3592-2E, and 3592-3E tape units, since they can write using a common recording technology.