Modify the Db2 definition to IRLM and MVS for data sharing: DSNTIJMV

You must modify the definition of Db2 for data sharing in the system parameter libraries of the target z/OS system.

About this task

Job DSNTIJMV demonstrates how to update the SYS1.PARMLIB members to identify Db2 to IRLM and MVS. Although you might edit and run this job, the more common approach is to examine the changes that DSNTIJMV makes and use an editor, such as ISPF/PDF, to make the required updated directly to the SYS1.PARMLIB members.

Because DSNTIJMV cannot anticipate all the necessary updates to identify Db2 to MVS and IRLM in your z/OS environment, additional updates might be required for your site. You can complete these updates either by making the updates directly in SYS1.PARMLIB members, or by editing and running the DSNTIJMV job.

Do not overwrite the entries for Db2 and IRLM in the program properties table (PPT). Note that PPT entries should no longer be defined in SYS1.PARMLIB(SCHEDxx). Default entries are supplied in the SYS1.LINKLIB(IEFSDPPT) load module, which is provided by z/OS. For details of the PPT entries, see Program properties table (PPT) .

Procedure

To modify the definition of Db2 for data sharing in the system parameter libraries of the target z/OS system:

  1. Examine the DSNTIJMV job and study the updates that it makes.
  2. Update the IEFSSNxx member of SYS1.PARMLIB by editing it directly, or by tailoring and running job DSNTIJMV.
    The IEFSSNxx member contains an entry for every z/OS subsystem. Db2 adds one entry for Db2 and two entries for IRLM in the list. The second IRLM entry, whose subsystem name is JRLM, simplifies adding a second IRLM to your system if the first is damaged. You must provide your own procedure to add JRLM. Unique names must be used for each entry.

    z/OS provides subsystem entries for Db2 and IRLM in IEFSSN00. Examine these entries to determine whether they are appropriate for your needs. Make sure that a subsystem name appears only once in the subsystem name list.

    Place the SMS line as the first line in an IEFSSNxx member. Place the primary system's record (JES2 or JES3) record next. Other products might affect the position of the entries during system initialization. The Db2 line should come after SMS, the JES subsystem, and other vendor products.

    The Db2 entry has the following format: 
    SUBSYS SUBNAME(ssname) INITRTN(DSN3INI)
   INITPARM('DSN3EPX,cmd-prefix<,scope<,group-attach<<,subgroup-attach>>>')
    ssname
    The Db2 subsystem name.
    DSN3INI
    The name of the Db2 load modulethat z/OS invokes during z/OS master scheduler initialization. This module must be located in a link list data set (or in SYS1.LINKLIB).
    DSN3EPX
    The name of the Db2 load module that responds to Db2 requests that are received from the z/OS® subsystem interface. (Db2 can be active or inactive when the requests are received.) This module must be located in a link list data set (or in SYS1.LINKLIB).
    cmd-prefix
    The one- to eight-character command prefix.

    The first character of the command prefix must be one of the following characters: @ # . / ' ) * + - = ¢ < | & ! ; % _ ? : ". The remaining characters of the command prefix must be one of the above characters, A-Z, or 0-9. Do not use the JES2 backspace character or command prefix character. The default is the hyphen (-).

    Do not assign a command prefix that is used by another subsystem or that can be interpreted as belonging to more than one subsystem or z/OS application. Specifically, do not specify a multiple-character command prefix that is a subset or a superset of another command prefix beginning from the first character. For example, you cannot assign '-' to one subsystem and '-Db2A' to another. Similarly, you also cannot assign '?DB2' to one subsystem and '?DB2A' to another. You can assign '-DB2A' and '-DB2B' to different Db2 subsystems.

    scope
    The one-character scope for the command prefix. Db2 registers its command prefix with the operating system. When this is done, the scope of the command prefix is controlled by the value you choose:
    S
    Started; and the prefix is registered with sysplex scope at Db2 startup instead of duringz/OS IPL. This is the default.

    Recommendation: Choose S, which allows you to have a single IEFSSNxx PARMLIB member that all z/OS systems in the sysplex can use. Choosing S also simplifies the task of moving a Db2 from one system to another; you can stop Db2 on onez/OS and start it up on another without having to re-IPL the system.

    M
    z/OS system scope; the prefix is registered during z/OS IPL.
    X
    Sysplex scope; the prefix is registered during z/OS IPL. As a result, this Db2 cannot be restarted on another z/OS without changing the definitions and re-IPLing both z/OS systems.
    group-attach
    The group attachment name, which is used for data sharing. You can specify this on installation panel DSNTIPK.
    subgroup-attach
    is the name of the subgroup attachment, which is used in data sharing environments to provide more control over how TSO, CAF, RRSAF, JDBC, ODBC, and Db2 utilities connections find active Db2 subsystems. You can specify this value by entering a subgroup name in the SUBGRP ATTACH field on installation panel DSNTIPK.