Primary/Shadow configuration requires that each MUF region runs with its own PXX dataset, i.e. PXX cannot be shared between the two MUF regions.
How to use a single JCL deck to start both the members of a Primary/Shadow MUF pair.
Here are two possible options:
1) use a temporary PXX dataset in the JCL:
//PXX DD DSN=&&PXX,UNIT=SYSDA,
2) if the MUF STCs are running on the two different LPARs (e.g. TST1 and TST2), then two permanent datasets can be allocated with dsn names like:
and then the PXX in the MUF startup can be referenced using the &SYSNAME variable:
//PXX DD DSN=hlq.&SYSNAME.PXX