System initialization for IRLM

To initialize the system for IRLM, you must define IRLM as a z/OS® subsystem.

Defining an IRLM as a z/OS subsystem

Your installation must assign a 4-byte subsystem name. You can use IRLM as the name, which assists the system operator in recognizing system messages sent to the console. This name must be unique to the z/OS system. If more than one IRLM subsystem is to run in an operating system, the names must be different.

An additional identification for each IRLM is a number in the range 1 to 255. The identification is required to internally differentiate between IRLMs. For example, two IRLMs that are to share data could have IDs of 1 and 2. Status and error messages sent to the system console operator contain the IRLM subsystem name and ID. Two IRLMs executing in a single z/OS system, or in different z/OS systems that are members of the same data-sharing group, require different ID numbers.

Another consideration for the IRLM subsystem name is that it must not be the same as that used for the startup procedure. This procedure is a member of SYS1.PROCLIB and is used by the operator in the START command. A unique START procedure must exist for each IRLM subsystem. The procedure library members are also distinguished by the different ID numbers and other control parameters.

The execution of the IRLM requires that the subsystem be added to the z/OS program properties table (PPT).

The system initialization routine for the subsystem must be null.

Related readings: