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There you can ask about the DIST and how it might impact other LPARs., Lizette > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of L Hagedorn > Sent: Wednesday, December 17, 2014 10:01 AM > To: [email protected] > Subject: Re: MIPS, CEC, LPARs, PRISM, WLM > > Thank you. > > Sent from my iPhone > > On Dec 17, 2014, at 11:36 AM, Ted MacNEIL <[email protected]> wrote: > > > PR/SM (LPAR) doesn't know PROD from TEST. > > It only knows weight. > > If you have set it up for LPAR to have 80% and LPARB to have 20%, that's what > they get in times of contention. No more, no less. > > 20% is one's allotment so it's okay. 85% is above the allotment so it's scaled back > to 80%. > > This is how it's always worked. > > > > > > - > > -teD > > - > > Original Message > > From: L Hagedorn > > Sent: Wednesday, December 17, 2014 11:15 > > To: [email protected] > > Reply To: IBM Mainframe Discussion List > > Subject: Re: MIPS, CEC, LPARs, PRISM, WLM > > > > Thank you for the extensive information and examples. > > > > I will be hitting the books. > > > > Can you expand on this example: > > > > If LPARA wants 85% and LPARB want 20% (total 105%) LPARB will get 20% and > LPARA will be squeezed to 80%. > > > > It seems counter intuitive to me and I'd like to understand. Lets say LPARA is prod > - they should get most of the resources. Why would LPARA be squeezed instead of > LPARB? > > > > Sent from my iPhone > > > > On Dec 17, 2014, at 9:07 AM, "Staller, Allan" <[email protected]> > wrote: > > > >> The answer is, "it depends". > >> > >> First, there is no "priority" across LPARS. All LPARS are dispatched "equally" > according to the LPAR weights. > >> > >> For example, if LPARA is weighted are 80 and LPARB is weighted at 20, the > following occurs: > >> > >> If LPARA wants 85% and LPARB wants 10% (total 85%) everybody is happy > and goes on their merry way. > >> > >> If LPARA wants 85% and LPARB want 20% (total 105%) LPARB will get 20% > and LPARA will be squeezed to 80%. > >> > >> If LPARA wants 50% and LPARB wants 40% (total 90%) everybody is happy > and goes on their merry way. > >> > >> The LPARA weight represents a "guaranteed minimum" proportion (note: > >> LPAR weights need not total to 100. The proportion is relative.) > >> > >> All of the above occurs when capping (either hard or soft) is not present. > >> > >> Software capping can occur with resource groups. > >> Hardware capping can occur with group capacity limits. > >> > >> This is a complex subject and much more than can be covered in a short e-mail. > >> > >> If you have not already done so, I suggest you obtain a copy of and read the > PR/SM Planning Guide. The most recent version I can find is SB10-7155-01 and is > located here: > >> https://www- > 304.ibm.com/support/docview.wss?uid=isg202e537c11be0929c8525776100663570 > &aid=1 (watch the wrap). > >> > >> RMF Monitor I (batch) has an excellent CPU report. This will also > >> include the "PARTITION DATA REPORT". I will refer you to the fine > >> manuals for details/ > >> > >> WLM *may* reach across LPAR Boundaries. If fact, it is designed to do this. > However, if the DVLP lpar is not in the same SYSPLEX, WLM cannot be a factor. > >> > >> As others have pointed out, what evidence is there that the "runaway" task is > affecting "production" (factual, not conjecture!)? > >> > >> HTH, > >> > >> <snip> > >> We have a situation with multiple LPARS on a CEC, running DB2 asids prod, > test, dev. > >> > >> It is claimed a runaway DB2 DIST asid on the DVLP LPAR is burning CPU and > stealing MIPS from the PROD LPAR and affecting production. > >> > >> Others claim this is not possible due to Prism. > >> > >> Will someone provide an overview of how Prism influences or controls MIPS > usage (CPU) across LPARs sharing the same CEC, what are the limiting or > controlling factors (if any), and how can the behavior be measured or reported upon > so I can explain this with supporting doc? Does WLM play a part in sharing CPU > across LPARs? > >> </snip> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
