Avoiding the PROFILE EXEC when IPLing CMS
Published 30 August 2002
Authors: Gregory Geiselhart
When logging on to CMS, the PROFILE EXEC found on the user's 191 A-disk is executed on CMS IPL. If a statement in the PROFILE EXEC causes a fatal CMS error, the user will be thrown into CP.
To correct the error, the PROFILE EXEC will need to be edited - typically using XEDIT. However, XEDIT only runs under CMS, leading to a dilemma - the PROFILE EXEC cannot be edited because CMS cannot be IPLed.
To resolve this problem, it is possible to IPL CMS without executing the user PROFILE EXEC, and this tip shows how to do this.
Most VM user IDs are set up to automatically start CMS when the user ID logs on to VM. Any time CMS is loaded (via the IPL CMS command), a special routine called PROFILE EXEC is automatically run. The PROFILE EXEC can contain a set of CP and CMS commands which define the current virtual machine and CMS environments. Many Linux guest virtual machines have a PROFILE EXEC which defines a working environment and then issues a CP IPL of the Linux machine. This makes the boot of a Linux guest nearly invisible to the end user.
There may be times, however, when you do not want the PROFILE EXEC and you simply want to run in CMS. Should you want to suppress the automatic invocation of the PROFILE EXEC, the first command you enter after the IPL CMS command is the CMS ACCESS command with the NOPROF option.
For example, you enter:
- ipl cms
The system response may be:
- z/VM V4.4.0 2002-07-11 10:58
To suppress the execution of your PROFILE EXEC, you enter:
- access ( noprof
When the system responds with:
Now you have loaded CMS and accessed filemode A without running your PROFILE EXEC.
This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a client responsibility and depends upon the client's ability to evaluate and integrate them into the client's operational environment.
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