z/OS interface considerations for IMS
There are many requirements that you must consider and required steps to ensure a
complete and correct installation of IMS on z/OS®. These topics describe these requirements and required
actions.
Preventing installation problems
Be sure to take the following actions to prevent problems during the installation of IMS on z/OS.
Setting up JCL
The following list contains the requirements for setting up your z/OS JCL.
Configuring JES for dependent regions
The EOM broadcast is always made when an IMS dependent region running as a started task ends, but the EOM broadcast may not be made, and therefore not processed, when a batch job ends.
Keeping some required nonstandard z/OS macros in their original libraries
The assembly of certain IMS modules requires z/OS macros not contained on the standard z/OS System Macro libraries. Because these requirements are subject to change due to IMS and z/OS maintenance, keep these macros in their original libraries, and use the JCL generated by IMS for SYS1.MODGEN (or SYS1.AMODGEN).
Updating the IBM-supplied z/OS Program Properties Table
The following modules are predefined in the default Program Properties Table (PPT) that is shipped with z/OS: BPEINI00, CQSINIT0, DFSMVRC0, and DXRRLM00.
Installing required IMS links to z/OS
You must install these modules and procedures on your z/OS system.
Installing the type 2 SVC module
The IMS Type 2 SVC must be incorporated into the z/OS nucleus.
Enabling memory-based data set ENQ management
The MEMDSENQMGMT function of z/OS enables jobs and subsystems to use memory-based data set ENQ management for dynamically allocated data sets, which is faster than scheduler work area-based (SWA-based) data set ENQ management. When you enable this function on your z/OS system, data set ENQs for dynamically allocated data sets are managed in memory.
IMS abend formatting module
IMS dynamically installs the IMS abend formatting module (DFSAFMX0). No user setup is required.
Adding the offline dump formatting routine to the print dump exit control table
Add the offline dump formatting module name to the Print Dump Exit Control Table in SYS1.PARMLIB member BLSCECT.
Binding the DBRC type 4 SVC
Bind the DBRC Type 4 SVC into an LPALIB or an MLPA library. It is named IGC00nnn, where nnn is the signed decimal SVC number.
Authorizing IMS system data sets in the Authorized Program Facility
If you use JOBLIB/STEPLIB with region types of CTL (DB/DC region type), DBC (DBCTL region type), or DCC (DCCTL region type), all concatenations of the JOBLIB/STEPLIB must be APF authorized.
Updating the APPC/MVS administration dialog
To use the APPC/MVS Administration Dialog utility with IMS TP Profiles, you must first add IMS as a transaction scheduler. To do this, you must add one line to the non-display panel ICQASE00 where the variable QASTSPE is defined.
RRS Archive Log Stream considerations
When using the z/OS Resource Recovery Services feature, be aware that the optional RRS Archive Log Stream has been found to generate large amounts of additional logging to the MVS logger.
System Management Facility DDCONS parameter considerations
The setting of the System Management Facility (SMF) DDCONS parameter should be reviewed to avoid possible processing delays, as described in APAR OY31613.
Restriction on multi-step jobs with SCI
Running a subsequent step in a job that registers with SCI is not supported when a prior jobstep created a space-switching PC.