You can specify one or more current DIAGxx parmlib members during IPL. For example, a DIAG=(03,04) system parameter tells the system to use DIAG03 and DIAG04 as current members. The system processes these members in the order they are specified. For all statements other than VSM TRACK, only the last statement for that option is honored. Before changing options with SET DIAG=xx, consider issuing a D DIAG command to see what options are currently in affect. Combine the displayed options with any new request that shares the same option statement.
The VSM TRACK parameter is cumulative. For example, if you specify VSM TRACK SQA(ON) in DIAG03 and VSM TRACK CSA(ON) in DIAG04, the system turns SQA/ESQA tracking on when it processes DIAG03, and turns CSA/ECSA tracking on when it processes DIAG04 (so both are turned on). The VSM TRACE parameter, in contrast, is not. For example, if you specify VSM TRACE GETFREE(ON) SUBPOOL(127) in DIAG03 and VSM TRACE GETFREE(ON) SUBPOOL(0) ASID(1) in DIAG04, the second specification replaces the first, with the result that the system performs a GFS trace for ASID 1 only.