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Nucleus Initialization Program and SVCs

When SVC update recording is active, CA Auditor first identifies the SVC update entries that are of specific interest to the data center. SVCUPDTE is used heavily during the execution of the Nucleus Initialization Program (NIP). In particular, NIP initializes all of the type 3 and type 4 SVCs and makes additional adjustments to other types of SVCs, including ENQ (enqueue) and DEQ (dequeue). These SVC updates indicate a properly functioning system. In general, they are of little interest. Therefore, CA Auditor focuses on SVC updates that occur as a result of logical Parmlib designations and data center programming, as is described in the following.

Systems permit the data center to define or modify predefined SVCs by one or more IEASVCxx logical Parmlib members. In those members, the SVCPARM statement and its parameters define the new SVC type, attributes, and name (or alias) of the load module that services the SVC requests. As in earlier releases of z/OS, all SVCs acquire control in an authorized state. The data center must carefully control SVCs. Updates made to IBM SVCs by IEASVCxx are particularly noteworthy because of the risks inherent in modifying IBM code.

It is important to determine the reason for any SVC updates made by data center programming and to understand SVC updates originated by IEASVCxx. CA Auditor identifies all SVC updates that occur once normal system operation begins‑that is, after the completion of NIP.

For more information about the SVCUPDTE Journal Analysis, Detailed Analysis, and Attribute Comparison functions, see the appropriate sections of the Technical Reference.