(zos)

Enable the reusable ASID function

If we are running the product on z/OS Version 1.9 or higher, we can use the updateZOSStartArgs script provided with the product to control for which of the servers, z/OS can reuse address space identifiers (ASIDs) associated with controllers.

• Verify that the REUSASID(YES) keyword is included in the z/OS DIAGxx PARMLIB member. This REUSASID option determines whether z/OS is enabled to reuse all ASIDs for the operating system image, including those associated with cross-process services. If the REUSASID option is set to NO, the ASIDs associated with the controller will not be reused even if we have run the updateZOSStartArgs script to enable this function for the product

• Start wsadmin.sh if it is not already running.

As stated in the z/OS Version 1.9 publication Communications Server IP Configuration Guide, SC31-8775-11, the TCP/IP address space provides cross-process routines, such as PC-entered services, that must be accessible to all address spaces. This requirement means that the Address Space Identifier (ASID) that is associated with the TCP/IP address space is not reusable when the address space is stopped or restarted. If the TCP/IP address space is terminated enough times, all available ASIDs might be exhausted, preventing the creation of a new address space on the system. If this situation occurs, stop z/OS and re-IPL.

z/OS Version 1.9 and higher includes a reusable ASID function that enables us to permit the use of all ASIDs, including those associated with cross-process services. If we run z/OS with this function enabled, we can run the updateZOSStartArgs script to enable or disable this function for a particular server, a particular node, or for all of the servers. For more information, see the conceptual information about the reusable address space.

Avoid trouble:

• If we are running the product in a mixed cell environment, even if you enable this function for all of the servers, only Version 6.1 and higher servers are able to use this function. For example, if you are running some Version 6.0 servers on the system, the ASIDs associated with the controllers for these servers cannot be reused.

• If we run the updateZOSStartArgsscript on z/OS Versions 1.6, 1.7, or 1.8, you will not get an error message. However those versions of z/OS ignore the z/OS Start argument that enables the reusable ASID function because the reusable ASID function is not available on those versions of z/OS.

gotcha

• Run the updateZOSStartArgs script, from the profile_root/bin directory for the deployment manager, to enable the reuse ASID function.

  The updateZOSStartArgs script is installed in the config_root/bin directory for the deployment manager.

  There are several options that can be specified for this script.

  For example, issue the following command to enable this function for all of the servers: wsadmin.sh -conntype NONE -lang jython -f /path/to/script/updateZOSStartArgs.py

  Issue the following command to enable this function for all of the servers on a particular node: wsadmin.sh -conntype NONE -lang jython -f /path/to/script/updateZOSStartArgs.py -node <nodeName>

• Run the updateZOSStartArgs script, from the profile_root/bin directory for the deployment manager, to disable the reuse ASID function.

  There are several options that can be specified for this script.

  For example, issue the following command to disable this function for a particular server: wsadmin.sh -conntype NONE -lang jython -f /path/to/script/updateZOSStartArgs.py -remove -node <nodeName> -server <serverName>

  Issue the following command to disable this function for any server that has the specified name: wsadmin.sh -conntype NONE -lang jython -f /path/to/script/updateZOSStartArgs.py -remove -server <serverName>

• After you run the script, restart any of the affected deployment manager, node agents, and servers that were running when you ran the script.

Results

After you run this script, the function remains enabled for the affected servers until you run the script to explicitly disable it.

If we enable this function in PARMLIB member DIAGxx for all of the servers, the function is automatically enabled for any new server that we create.

The REUSASID parameter is automatically set to YES for any new servers that we create. You do not need to rerun the updateZOSStartArgs script on newly created servers unless to disable the reuse ASID capability.

Subtopics

• (zos) updateZOSStartArgs script
  If we are running the product on z/OS Version 1.9 or higher, we can use the updateZOSStartArgs script provided with the product to control for which of the servers, z/OS can reuse address space identifiers (ASIDs) associated with cross-process services when those services end.

Related tasks

Start the wsadmin scripting client