RNL defaults

Because the resources to include in each RNL depend on the needs of your installation, it is not possible to supply default RNLs that will work well in every environment. IBM® does supply a default for each RNL; Figure 1 shows these defaults.

The generic qname entry for SYSDSN in the SYSTEM inclusion RNL indicates that all data sets that go through MVS™ allocation (except for VIO and subsystem data sets, such as SYSIN, SYSOUT, and SUBSYS data sets) are to be global resources. The entries in the SYSTEMS exclusion RNL identify the system data sets with a qname of SYSDSN that specifically cannot be global resources.

Figure 1. Contents of the default RNLs

SYSTEM inclusion RNL:

SYSDSN

SYSTEMS exclusion RNL:

SYSDSN SYS1.BRODCAST
SYSDSN SYS1.DAE
SYSDSN SYS1.DCMLIB
SYSDSN SYS1.DUMP (generic — all dump data sets)
SYSDSN SYS1.LOGREC
SYSDSN SYS1.MAN (generic — all SMF data sets)
SYSDSN SYS1.PAGE (generic -- all page data sets)
SYSDSN SYS1.STGINDEX
SYSDSN SYS1.UADS

RESERVE conversion RNL:

The RESERVE conversion list is empty.

You can IPL the systems in your GRS complex and build a ring using the default RNLs, but an IPL with the default RNLs might not reflect all the goals your installation has for the global resource serialization complex.

For example, you might want to change the contents of the default RNLs to emphasize RESERVE conversion and avoid potential interlocks. The DISPLAY GRS,CONTENTION command provides information about resources that are causing contention, and RMF™ reports can also help. The most useful RMF reports related to the system delay activity are:

Monitor I enqueue activity report
Monitor II system enqueue contention (SENQ) and system enqueue reserve (SENQR) reports
Monitor III (workload delay monitor) reports on resource-oriented enqueue delays and resource-oriented device delays

Guideline: Use the ENQ/RESERVE/DEQ monitor to help plan RNL use. See Using the ENQ/RESERVE/DEQ monitor tool.

Because a global resource serialization complex can consist of multiple levels of z/OS® systems, and because each system control program usually works with multiple levels of other products, it is not possible to compile a complete and exhaustive list of recommended treatment for resources in all possible situations. There are, however, some general guidelines as well as some specific suggestions on known resources that are good candidates for the SYSTEM inclusion RNL, the SYSTEMS exclusion RNL, and the RESERVE conversion RNL. These guidelines and suggestions cover the following topics:

The information is meant to give you an idea of the kind of decisions you might need to make, and it does not deal with the specifics of every level of every product.

If you need more information about the macros mentioned in the following explanation, see: