BPXPRMxx (z/OS UNIX System Services parameters)

BPXPRMxx contains the parameters that control the z/OS® UNIX System Services (z/OS UNIX) environment and the file systems.

To make it easier to migrate from one release to another, especially when using the ServerPac method of installation, use two BPXPRMxx parmlib members. One member defines the values to be used for system setup and the other member defines the file systems.

To specify which BPXPRMxx parmlib member to start with, the operator has two choices:
  • Include OMVS=xx in the reply to the IPL message.
  • Include OMVS=xx in the IEASYSxx parmlib member. The two alphanumeric characters, represented by xx, are appended to BPXPRM to form the name of the BPXPRMxx parmlib member.

If OMVS=xx is not specified in the reply to the IPL message, defaults are used for each parameter and the kernel services are started in minimum mode. If OMVS=DEFAULT is specified, defaults are also used for each parameter and the kernel services are also started in minimum mode. For more information about running in minimum mode and full function mode, see Setting up kernel services in minimum mode and Setting up kernel services in maximum mode in z/OS UNIX System Services Planning. If the operator specifies OMVS=xx in the reply to the IPL message, it overrides the OMVS=xx that was specified in IEASYSxx.

Restriction: The START OMVS,OMVS=xx command is not valid when issued from the command console. OMVS=xx is not valid in parmlib COMMNDxx.
You can use multiple parmlib members to start OMVS as shown in the following reply to the IPL message: 
R 0,CLPA,SYSP=R3,LNK=(R3,R2,L),OMVS=(AA,BB,CC)
You can also specify multiple BPXPRMxx parmlib members using the OMVS keyword in IEASYSxx. For example: 
OMVS=(AA,BB,CC)

If the same parameters are specified in more than one member, the first instance of the keyword that is specified in the leftmost member is used. The MOUNT statements are processed in the order that they are specified in left to right sequence.

If you are using SYSPLEX(YES) and mixed releases of z/OS UNIX, you can IPL specifying OMVS=(delta,common) for each unique release, where delta identifies the member containing the new keywords for that release, and common identifies the common keywords for all releases.

To modify BPXPRMxx parmlib settings without reloading the initial program, you can use the SETOMVS operator command. You can also dynamically change the BPXPRMxx parmlib members that are in effect by using the SET OMVS operator command. For more information, see Dynamically changing certain BPXPRMxx values in z/OS UNIX System Services Planning. For more information about the SETOMVS command, see SETOMVS command in z/OS MVS System Commands. For more information about the SET OMVS command, see SET command in z/OS MVS System Commands.