IRLM names

Each member of a data sharing group has its own IRLM. The IRLM group name, subsystem name, and member ID are parameters on the IRLM startup procedure.

This means that every IRLM in the group must have a separate IRLM procedure. The following figure shows the relationship between Db2 group names and IRLM group names.

Figure 1. Relationship between Db2 and IRLM group names
Begin figure summary. The data sharing group has a corresponding IRLM group and each member of the data sharing group has its own IRLM. Detailed description available.
You must choose the following IRLM names before installing Db2:
IRLM group name
The name that encompasses the entire IRLM group. This name can be up to eight characters long and can consist of the characters A-Z, 0-9, $, #, and @. The group name must begin with an alphabetic character. The name must be unique across the Parallel Sysplex®.
Restriction: To avoid names that IBM® uses for its XCF groups, do not begin with the letters A-I unless the first three characters are DXR. Do not use the string SYS as the first three characters, and do not use the string UNDESIG as your group name.

The IRLM group name is a parameter (IRLMGRP=) on each member's IRLM procedure. An example IRLM group name is DXRDB0A, a naming convention that you can use to associate member DB0A with DXRDB0A.

IRLM subsystem name
Each IRLM must have a subsystem name that must be unique within the data sharing group and can be up to four characters long and. This name is a parameter on the IRLM procedure.

A sample subsystem name is DJ1A. The 1A characters indicate that this IRLM is paired with the member DB1A.

IRLM procedure name
Each member of a data sharing group knows its IRLM by the procedure and subsystem names saved in that member's installation parameter load module. The IRLM procedure name can be up to eight characters long.
Recommendation: Use the member subsystem name followed by IRLM. An example IRLM procedure name is DB1AIRLM.
IRLM member ID
This ID uniquely names an IRLM within a group. It is a parameter on the IRLM procedure and must be unique within the data sharing group. It is a number in the range 1–255 (inclusive).

The following names also apply to IRLMs:

IRLM XCF member name
This name can be up to 16 characters long. An example IRLM XCF member name is xxxxxxxx$issnNNN, where xxxxxxxx is the IRLM group name, issn is the IRLM subsystem ID, and NNN is the IRLM member ID. Dollar signs ($) are used as padding. This name is generated at startup time.
Lock structure connection name
The connection name is the same as the IRLM XCF member name. It is generated by IRLM. You see it only as the output of certain commands (such as z/OS® D XCF,STRUCTURE). In some cases, the connection name can be of the format xxxxxxxx#issnNNN.