This chapter describes the new REGIONX keyword on the JOB and EXEC JCL statements. It also describes the differences and similarities between the REGIONX and REGION keywords.

This chapter includes the following topics:

To run their jobs and applications in controlled environments, users want more control over their below-the-line and above-the-line storage requests. Although the old REGION specification can be used to control memory usage, users cannot specify values for below- and above-the-line storage. Because REGION uses its own rules for defining below- and above-the-line values, a user can have more below-the-line storage than they want and less above-the-line storage than they need.

The new REGIONX JCL keyword supports two storage specifications and with which the user can explicitly specify values for their below-the-line storage and above-the-line storage needs. This specification allows an installation to reduce the amount of below-the-line storage that must be available to process jobs.

You can code the REGIONX keyword on JOB and EXEC JCL statements, but it is mutually exclusive with the REGION keyword. Therefore, if REGIONX is coded in your JOB card, none of the JOB steps can have REGION set, and vice versa.

To define the amount of required storage, you can code below-the-line, above-the-line, or both. Table 2-1 lists possible REGIONX configurations.

You can code up to five numeric digits and a unit specification for each allocation. K and M are allowed for below-the-line storage, and K, M, and G are allowed for above-the-line storage. In the case of REGIONX on an EXEC statement, either or both of these values can be defaulted to the REGIONX values on the JOB statement if it was specified.

Also, coding REGIONX in your EXEC JCL statement causes it to override any REGIONX values that are defined in the JOB statement. This configuration allows storage requirements to be tailored to a particular job step while allowing the JOB statement specification to act as a default when REGIONX= is not specified on an EXEC statement.

The Example 2-1 shows a sample JCL with REGIONX coded on JOB and EXEC statements. STEP2 requests 4 M of storage below-the-line, which overrides the JOB default of 2 M.

The REGIONX keyword can be used in JOBs and STEPs, including JOBs and procedures that are started by the START command. In these cases, the following scenarios are possible:

A new sample SMF Step Initiation Exit routine is available on SYS1.PARMLIB to assist customers in configuring their exits to handle REGION and REGIONX keyword.

Customers must rename it to IEFUSI, then customize, assemble, link, and place it into LPALIB so that it can be used.