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 address spaces are new for z/OS V2R1:

PCIE (PCI Express) and FPGHWAM (Hardware Accelerator Manager). They provide the infrastructure for PCI Express I/O and hardware accelerator activities. These address spaces are started automatically during z/OS initialization, if the appropriate z/OS PCIE facilities hardware is installed (that is, if you running on at least a zEC12 or zBC12). They are persistent address spaces.
If the PCIE address space is successfully initialized, the message is displayed:
```
IQP002I PCIE INITIALIZATION COMPLETE 
```
If the required hardware is not installed (that is, you are not running on at least a 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 you apply any specific security customizations that may 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 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 name of the address spaces are jesxCInn where jesx is the JES2 subsystem name and xx is a number (from 01 to 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) 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.

There are two new address spaces in z/OS V1R13, also available in z/OS V1R12 with RMF APAR OA36030 applied.

GPM4CIM is an address space to be used for cross-platform performance management with RMF XP. You can start it by using procedure SYS1.PROCLIB(GPM4CIM) from the console, as started task, with the following command:
```
s gpm4cim[.identifier],os=A|X|Z
```
Since you can run multiple GPM4CIM instances simultaneously, it is recommended to assign an identifier that you can use for subsequent STOP or MODIFY commands. You may already have created the userID GPMSERVE as owner of the GPMSERVE procedure. The GPM4CIM started task can be assigned to the same userID with the following command:
```
RDEFINE STARTED GPM4CIM.* STDATA(USER(GPMSERVE) TRUSTED(YES))
```
As of z/OS V1R13 the Runtime Diagnostics address space HZR will be a persistent address space. When the HZR address space is started with the START command S HZR,SUB=MSTR, it will remain active until stopped with the STOP command P HZR. To analyze a system, enter the MODIFY HZR,ANALYZE command. See Start Runtime Diagnostics at system initialization.

Element or feature:

BCP, JES, and RMF.

When change was introduced:

z/OS V1R13 for GPM4CIM and HZR
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 and z/OS V1R12.

Timing:

Before the first IPL of z/OS V2R1.

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 take the new address spaces into account. One way to find out how many address spaces you use is to issue the DISPLAY A,L command and total the address spaces in the IEE114I and IEE115I messages on the old and new systems.

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 your 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.