Dynamically switching to different BPXPRMxx members

Another way to dynamically reconfigure parameters is to use the SET OMVS command to change the BPXPRMxx members that are in effect. With the SET OMVS command, you can have multiple BPXPRMxx definitions and use them to easily reconfigure a set of the z/OS UNIX system characteristics. You can keep the reconfiguration settings in a permanent location for later reference or reuse.

For example, you could keep the system limits parameters that can be reconfigured in parmlib member BPXPRMLI. When you need to change any of the limits, edit the parmlib member and then issue SET OMVS. For example:

SET OMVS=(LI)

Changes to system limits (for example, MAXPROCSYS) take effect immediately. Changes to user limits (for example, MAXTHREADS) are set when a new user enters the system (for example, rlogin or a batch job). These limits persist for the length of the user connection to z/OS UNIX.

Restriction: While the MAXPROCSYS, MAXPTYS, IPCMSGNIDS, IPCSEMNIDS, IPCSHMNIDS and IPCSHMSPAGES values can be changed dynamically, the changes are limited by the initial value that was used at IPL time, as described in Dynamically changing certain BPXPRMxx parameter values. SHLIBRGNSIZE and SHLIBMAXPAGES are not affected by this restriction.

SET OMVS=xx can be used to execute the ROOT, MOUNT, FILESYSTYPE, SUBFILESYSTYPE, and NETWORK statements in the BPXPRMxx member.