Using IBM Health Checker for z/OS

The IBM® Health Checker for z/OS® includes several global resource serialization checks. This section gives a brief overview of the checks. For installation overrides of IBM parameters and detailed information see Global resource serialization checks in IBM Health Checker for z/OS: User's Guide.

The following checks examine the configuration and tuning of your global resource serialization complex against best practices.

GRS_CONVERT_RESERVES: This check looks for the recommended best practice of possibly converting all RESERVEs. Converting RESERVEs to global ENQs can help avoid deadlocks and improve reliability, availability, and serviceability. Note that some RESERVEs should not be converted. For more information on converting RESERVES, see RESERVE conversion.
GRS_EXIT_PERFORMANCE: This check examines exit points. The use of certain global resource serialization dynamic exits can negatively impact system performance. In some cases, removing an exit module or changing it to use a different exit point can help improve performance. For more information on dynamic exits, see z/OS MVS Installation Exits.
GRS_GRSQ_SETTING: This check examines the GRSQ setting and is only applicable in global resource serialization STAR mode. The recommended GRSQ setting, GRSQ=CONTENTION, produces smaller dump sizes and reduces the amount of time needed to create the dump.
GRS_MODE: This check determines if global resource serialization is running in star or ring mode. A star configuration is recommended for advantages in availability, real storage consumption, processing capacity, and response time. See Star advantages.
GRS_RNL_IGNORED_CONV: This check examines the RESERVE conversion list for entries that always supersede entries in the SYSTEMS exclusion list. For example, an installation expected a RESERVE to be converted into a global ENQ, but instead it is processed as a RESERVE and local ENQ because an entry is found in the SYSTEMS exclusion list first. The check generates a list of problem entries.
GRS_SYNCHRES: This check examines global resource serialization synchronous RESERVE processing. Enabling global resource serialization synchronous RESERVE processing can prevent deadlock conditions. See Understanding the synchronous RESERVE feature.