On Wed, 11 Apr 2012 10:24:10 -0400, Mark Jacobs
wrote:
>We had a discussion yesterday regarding our obsolete IEFUSI exit and how
>it should be modernized to even know about the virtual storage region
>above the 2GB line.
>
>One of the concerns was that since IEFUSI has no practicable effect on
>authorized programs I was asked to come up with some ways to better
>manage our environment just in case some user decides to allocate and
>start using massive amounts of above the bar storage.
>
>My question to the mailing list is do you manage towards this scenario
>and if so, how?
>
I'm not really worried about STCs and authorized users. Nothing I can do
about them except allocate 2000 page volumes (just kidding).
The comments in my IEFUSI exit from 2005 still hold true and explain
what I am doing. So far, it has worked out fine. My client does have
64-bit usage and also large pages running 64-bit WebSphere.
Basically, I just want to keep someone from "playing" with 64-bit
from destroying the system.
My SMFPRMxx MEMLIMIT is to 10G.
9/14/2005 M ZELDEN FORCE MEMLIMIT OF 5G FOR ANY JCL
SPECIFICATION OF ANYTHING OVER 5G BUT
ALLOW MEMLIMIT NOLIMIT (16383PB) IF
REGION=0M. IF NO JCL SPECIFICATION IS
USED (OTHER THAN REGION=0M), THEN TAKE
THE MEMLIMIT DFLT FROM SMF (SMFPRMXX).
THIS WILL ALLOW SYSTEMS THAT NEED A
HIGHER MEMLIMIT TO HAVE SMFPRMXX BE
THE CONTROLLING FACTOR - AS LONG AS
MEMLIMIT IS NOT SPECIFIED IN THE JCL.
SINCE ONLY STCS CAN USE REGION=0M, ONLY
STCS WITH REGION=0M CAN GET MORE THAN
THE FORCED MEMLIMIT OR THE SMF DFLT.
By having SMFPRMxx be the controlling factor, I could easily raise it
if a problem came up with no JCL changes etc. So far, I've haven't
needed to do that. Keep in mind I updated this exit for the brave
new world in 2005. I'm slightly surprised it's been 7 years and
I haven't needed to modify it except for a change in 2007 related to
OA14391 which affected z/OS 1.7 & z/OS 1.8 and above. That
APAR kept STCs with REGION=0M from getting MEMLIMIT=NOLIMIT
so I updated the exit to force MEMLIMIT=NOLIMIT for STCs with
REGION=0M (which was the behavior prior to OA14391).
Regards,
Mark
--
Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS
mailto:m...@mzelden.com
Mark's MVS Utilities: http://www.mzelden.com/mvsutil.html
Systems Programming expert at http://expertanswercenter.techtarget.com/
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