Accommodate new address spaces

Description

The MAXUSER value in parmlib member IEASYSxx specifies a value that the system uses to limit the number of jobs and started tasks that can run concurrently during a given IPL. You might want to increase your MAXUSER value to take new address spaces into account.

The following elements add new address spaces for z/OS V2R2:
The following address spaces were new for z/OS V2R1:
  • Start of changeSDSFAUX (SDSF). With APAR PI43902 (also applicable to z/OS V2R2), SDSF is enhanced with a new, optional address space called SDSFAUX, which provides information about the systems in the sysplex, and their various data set concatenations. The information is shown on the following new SDSF panels and their associated commands: APF, LNK, LPA, PAG, PARM, and SYS.

    The SDSFAUX address space is automatically started by the SDSF server address space when the server starts, and is automatically stopped when the SDSF server is stopped.

    For more information about SDSFAUX, see z/OS SDSF Operation and Customization.

    End of change
  • PCIE (PCI Express) and FPGHWAM (Hardware Accelerator Manager). These address spaces provide the infrastructure for PCI Express I/O and hardware accelerator activities. They are started automatically, if z/OS is IPLed on a hardware server capable of supporting the appropriate z/OS PCIE facilities, even if the PCIE facilities are not available on the server. This capability is available on a zEC12 or zBC12 or later. They are persistent address spaces. It is recommended that you do not stop them if any other subsystem relies on them.
    When the PCIE and FPGHWAM address spaces are successfully initialized, the following message is displayed: 
    IQP002I PCIE INITIALIZATION COMPLETE
    If z/OS is IPLed on a server that precedes the zEC12 or zBC12, the following message is written to the hardcopy log: 
    IQP031I REQUESTED SERVICE IS UNSUPPORTED BY HARDWARE

    For information about the PCIE messages, see z/OS MVS System Messages, Volume 9 (IGF-IWM). For information about the FPGHWAM (Hardware Accelerator Manager) messages, see z/OS MVS System Messages, Volume 5 (EDG-GFS).

    PCIE and FPGHWAM do not require any security customization. However, if you are using any enhancements that use this infrastructure, check the documentation for those enhancements to ensure that you apply any specific security customization that might be required for their use.

  • IBM Health Checker for z/OS. As of z/OS V2R1 the system starts IBM Health Checker for z/OS address space automatically during system initialization.

    For information, see Convert your existing IBM Health Checker for z/OS setup for automatic start-up.

  • JES2 Converter/Interpreter. A new persistent address space is used when the interpretation process is performed for a job during the JES2 conversion phase. The address space is only created when INTERPRET=JES is specified on JOBDEF. The number of address spaces that are used depends on the CISUB_PER_AS setting on JOBDEF. The number of conversion processes (PCEDEF CNVTNUM=) divided by the number of subtasks per address space (CISUB_PER_AS) gives the number of address spaces created. The default number of created address spaces is 2 and the maximum number is 25.

    The address spaces are named jesxCInn, where jesx is the JES2 subsystem name and xx is a number (01 - 25) to create uniqueness. This address space accesses the PROCLIB data sets defined in the JES2 start PROC and using the JES2 dynamic PROCLIB service.

    You must ensure that a proper user ID is assigned to the address space (presumably the same user ID that is assigned to the JES2 address space) by using entries in either the started procedures table (ICHRIN03) or that a STARTED class profile has been defined that matches each new address space names. If you prefer, both the started procedures table and STARTED class profile might be in place. This action ensures that the correct user ID is assigned.

  • Generic Tracker (GTZ). As of z/OS V2R1, GTZ replaces the Console Tracking Facility with enhanced capabilities to track use of system functions. For information, see Move from the console tracking facility to the Generic Tracker.

Table 1 provides more details about this migration action. Use this information to plan your changes to the system.

Table 1. Information about this migration action
Element or feature: BCP, JES, and RMF.
When change was introduced:
  • z/OS V2R1 for the following:
    • BCP PCIE (PCI Express) and FPGHWAM (Hardware Accelerator Manager).
    • IBM Health Checker for z/OS
    • JES2
    • GTZ
Applies to migration from: z/OS V1R13.
Timing: Before the first IPL of z/OS V2R2.
Is the migration action required? No, but recommended to ensure that your MAXUSER value in parmlib member IEASYSxx is adequate.
Target system hardware requirements: None.
Target system software requirements: None.
Other system (coexistence or fallback) requirements: None.
Restrictions: None.
System impacts: None.
Related IBM Health Checker for z/OS check: None.

Steps to take

If necessary, increase your MAXUSER value in parmlib member IEASYSxx to accommodate the new address spaces. One way to determine how many address spaces you use is to enter the DISPLAY A,L command. Then, add the number of address spaces in the IEE114I and IEE115I messages on the old and new systems to determine the total number.

Note:
  • A modest overspecification of MAXUSER should not affect system performance.
  • The number of total address spaces is the sum of M/S, TS USERS, SYSAS, and INITS.
  • If you change the MAXUSER value, you must re-IPL to make the change effective.

Reference information

For more information about the MAXUSER parameter, see z/OS MVS Initialization and Tuning Reference.

Parent topic: Migration actions for everyone before the first IPL of z/OS V2R2