On Thu, 27 Oct 2005 14:05:34 +0200, Barbara Nitz wrote: >In early September we had another lengthy discussion about this topic. Now I >have gotten around to changing our IEFUSI, after having learned that there >is shared storage above the bar that doesn't count against MEMLIM and now >that we are starting to use DB2 V8. > >That brings up two question for me: > >1. DB2's DBM1 address space doesn't care what IEFUSI sets for a memlim, it >just goes and overwrites the USI specified value with 4TB. (Not this >clearly, but it is sort of documented in a DB2 apar.) I would be interested >to know how they do it: Is there an official interface (that I just haven't >found) or do they go and overwrite the value in the RAX? (Hopefully by also >documenting that they did this by setting RAXLVAUTH.) > >Clearly the Extended addressability guide is wrong when it says that >"the MEMLIMIT specified in an IEFUSI exit routine overrides all other >MEMLIMIT settings" - so should I turn in an RCF? > >2. Is there any way (other than TMONMVS, I believe) to detect that an >address spaces uses storage above the bar? (I know - RMF can do it when >VSTOR for private is active - this I wouldn't want to do) Given that DB2 is >authorized, a bug in there could use up all 4TB even if we were in an AUX >storage shortage - and our paging configurations will not be able to handle >4TB page space - no matter what the DB2 apar states. (And just how many mod3 >would that be, anyway?) > >Best regards, Barbara Nitz >
Do you specify MEMLIMIT in MB? FLASH10165 Limiting Storage use above the bar in z/Architecture Document Revised: 10/12/2005 http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/FLASH10165 reads: MEMLIMIT Enforcement Through IEFUSI The SMF IEFUSI exit can change the MEMLIMIT value by updating the value in the third double word. But the publication failed to mention the value used is in the unit of MB (for example, 00000000 00008400 is 33 GB). z/OS 1.7 MVS Installation Exits Document Number SA22-7593-09 Tenth Edition, September 2005 reads: Sub-parameter 3 The 64-bit MEMLIMIT requested by the IEFUSI exit. The initial value is X'FFFFFFFFFFFFFFFF' to indicate that no value was set by the exit. If not changed, SMF uses the MEMLIMIT that was originally requested. This value is specified in megabytes. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
