[z/OS]

Link pack area, link list, and STEPLIB

By placing load module data sets in the link pack area (LPA) and system link list, you can obtain improved MVS system performance and some virtual storage savings.

Product data sets

You can place only one set of WebSphere® Application Server for z/OS® load modules (any release) in the link pack area and link list because the same load module names are used across releases. For each application serving environment, the Customization Dialog or Profile Management tool is used to specify whether the environment's product data sets are already in the link pack area and link list or require loading from STEPLIB.

If load modules for a previous version of WebSphere Application Server for z/OS are in the system link pack area and link list, you must run the new version of WebSphere Application Server for z/OS from STEPLIB. If no previous version is in the system link pack area and link list, then you can choose a set of WebSphere Application Server for z/OS product libraries and place them in the link pack area and link list.

Recommendations:
  • Choose the WebSphere Application Server for z/OS product data sets that your production application serving environment will use.
  • Plan to load SBBOLOAD into the system link pack area. This will require approximately 8K of common storage below the 16M line and between 20M and 40M of extended common storage. (In version 6 release 1, only the CTRACE support module remains in SBBOLPA.)
  • Plan to load SBBOLD2 into the system link list. You cannot place this data set in the link pack area.

System data sets

The WebSphere Application Server for z/OS customization process assumes that the following data sets are in the system link list:
  • SCEERUN
  • SCEERUN2
  • System SSL (SGSKLOAD or SIEALNKE)

If these data sets are not in the link list, be sure to follow the optional customization steps that direct you to add these data sets to STEPLIB concatenations in WebSphere Application Server JCL, and in the setupCmdLine.sh script. Certain Language Environment® load modules can be placed in the link pack area, providing performance improvements. For more information see the Language Environment® Customization manual for your z/OS release.

STEPLIB statement in setupCmdLine.sh

Each WebSphere Application Server for z/OS node home directory uses a setupCmdLine.sh shell script to set environment variables during the execution of administrative scripts. One of the functions of this shell script is to set the STEPLIB variable, which provides STEPLIB capability when running a file system executable file.

During initial node configuration, the Customization Dialog sets the value of the STEPLIB variable in setupCmdLine.sh to the same list of data sets as the STEPLIB concatenation in the node's cataloged procedures. You might need to update this shell script (which resides in WAS_HOME/profile/default/bin for each node) for a variety of reasons. Update the shell script if you do any of the following:
  • Change which WebSphere Application Server for z/OS product code level is in the system link pack area and link list.
  • Apply maintenance and need to change which WebSphere Application Server for z/OS product code level a cell is using.
    Note: All nodes in a cell on the same system must use the same product code level.
  • Need to add additional STEPLIB data sets. (For example, for DB2® or CICS® interfaces.)
To update STEPLIB in setupCmdLine.sh, edit the copy of the script in each affected WAS_HOME/profile/default/bin directory and find lines similar to the following:
	STEPLIB='WAS.V60.TEST.SBBOLD2':$STEPLIB
	STEPLIB='WAS.V60.TEST.SBBOLOAD':$STEPLIB
	export STEPLIB
Edit the lines as needed, however, don't remove lines requiring variable input. Be sure to update each node's setupCmdLine.sh script, including the one for the deployment manager.

Switching between LPA/LNKLST and STEPLIB

If you decide to move a particular level of WebSphere Application Server for z/OS product code (previously run from STEPLIB) into the system link pack area and link list, perform the following steps:
  1. Identify the application serving environments making use of these product libraries. (That is, the ones that have cataloged procedure STEPLIB statements for these particular SBBOLPA, SBBOLOAD and SBBOLD2 data sets.)
  2. Identify the application serving environments making use of these product libraries. (That is, the ones that have cataloged procedure STEPLIB statements for these particular SBBOLPA, SBBOLOAD, SBBGLOAD and SBBOLD2 data sets.)
  3. Make sure that no other version of WebSphere Application Server for z/OS is in either the link pack area or link list.
  4. Place SBBOLOAD and SBBGLOAD in either the link pack area or link list, and place SBBOLD2 in the link list.
  5. Edit all WebSphere Application Server for z/OS cataloged procedures that use these data sets, removing SBBOLPA, SBBOLOAD, SBBGLOAD and SBBOLD2 from any STEPLIB in which they appear. In the cataloged procedures generated by the Customization Dialog, the proclib members that will require editing are the INCLUDE JCL members that have names ending in "Z".
  6. For Version 6 Release 1, load a copy of BBORTS61 load module from SBBOLPA into the system link pack area. This load module is required for component trace support; all levels of Version 6 Release 1 can share the same copy of BBORTS61.
If you no longer want to run a particular level of WebSphere Application Server for z/OS product code from LPA / link list, and you want to run it from STEPLIB instead, perform the following steps:
  1. Identify the application serving environments that make use of these product libraries. (That is, the ones that do not have cataloged procedure STEPLIB statements for SBBOLPA, SBBOLOAD, SBBGLOAD and SBBOLD2.)
  2. Edit all WebSphere Application Server for z/OS cataloged procedures for these application serving environments. In the cataloged procedures generated by the Customization Dialog, the proclib members that will require editing are the INCLUDE JCL members that have names ending in "Z".
    • Add SBBOLOAD and SBBGLOAD to the STEPLIB concatenation in all location service daemon cataloged procedures and in all controller and servant cataloged procedures.
  3. For each of the affected application serving environments, add SBBOLOAD, SBBGLOAD and SBBOLD2 to the STEPLIB statement in the WAS_HOME/profile/default/bin setupCmdLine script in each WebSphere Application Server home directory.
  4. Modify IPL procedures so that the WebSphere Application Server for z/OS data sets are no longer in the system link pack area and link list.
  5. Ensure that you continue to load a copy of the BBORTS61 load module (release independent) into the system link pack area. You can load this module from any Version 6.1 or later SBBOLPA data set.



Related concepts
Product data sets
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