I don't think you'll impact performance negatively, no -- BUT - you will be cutting your paging space in half.. so you will not be able to support as high a virtual to real ratio as you could now. The current numbers look 'ok' - and your paging would be at about 30% or after you change to a mod 3 with identical paging use.
If you could replace the mod9 with THREE mod 3's -- that would give you the same amount of paging space you have now. You might want to check out Bruce Hayden's VIR2REAL package on the VM downloads page: http://www.vm.ibm.com/download/packages/descript.cgi?VIR2REAL Knowing how overcommitted your storage is helps you know how much paging space you should have. Simple formula is something like: 2 x virtual - real. Scott Rohling On Wed, Oct 6, 2010 at 12:08 PM, George Henke/NYLIC < george_he...@newyorklife.com> wrote: > > I currently have a mod 3 and a mod 9 Page Pack at L1. > > Brian suggests using this maintenance upgrade as an opportunity to > eliminate the mixed PAGE Packs at L1. > > My Storage Group is balking at the idea of giving me another mod 9 for > paging. > > Will I impact performance if I replace my 2nd mod 9 Page pack at L1 with a > mod 3, to match the other mod 3 page pack? > > Here is some L1 steady state data: > > Q ALLOC PAGE > EXTENT EXTENT TOTAL PAGES HIGH % > VOLID RDEV START END PAGES IN USE PAGE USED > ------ ---- ---------- ---------- ------ ------ ------ ---- > 540PAG 10BA 1 3338 600840 201633 403918 33% > 540PG2 12CD 1 10016 1761K 189808 371828 10% > ------ ------ ---- > SUMMARY 2347K 391441 16% > USABLE 2347K 391441 16% > Ready; T=0.01/0.01 13:56:15 > > > > *Brian Nielsen <bniel...@sco.idaho.gov>* > Sent by: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU> > > 10/05/2010 12:45 PM > Please respond to > The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU> > > To > IBMVM@LISTSERV.UARK.EDU > cc > Subject > Re: Multi Page/Spool Directory Defs > > > > > As others have mentioned, they are placeholders to prevent directory > managment software from allocating minidisks on them. > > What I also noticed was that your PAGE space is a mix of DASD sizes. > > Check out the recent thread discussing the pitfalls of doing so. You > might want to fix that on your 1st level system. > > Brian Nielsen > > On Tue, 5 Oct 2010 10:52:50 -0400, George Henke/NYLIC > <george_he...@newyorklife.com> wrote: > > >My Level 1l PAGE and SPOOL disks have only the first volume defined in t > he > >Directory. > > > >* > >USER $PAGE$ NOLOG > > MDISK A03 3390 000 END 540PAG R > >* > >USER $SPOOL$ NOLOG > > MDISK B01 3390 000 END 540SPL R > >* > > > >Yet, Q ALLOC PAGE and SPOOL recognize a second volume for each: > > > >q alloc page > > EXTENT EXTENT TOTAL PAGES HIGH % > >VOLID RDEV START END PAGES IN USE PAGE USED > >------ ---- ---------- ---------- ------ ------ ------ ---- > >540PAG 10BA 1 3338 600840 198644 395999 33% > >540PG2 12CD 1 10016 1761K 184565 364318 10% > > ------ ------ ---- > >SUMMARY 2347K 383209 15% > >USABLE 2347K 383209 15% > >Ready; T=0.01/0.01 10:49:47 > >q alloc spool > > EXTENT EXTENT TOTAL PAGES HIGH % > >VOLID RDEV START END PAGES IN USE PAGE USED > >------ ---- ---------- ---------- ------ ------ ------ ---- > >540SPL 106C 1 3338 600840 506931 600840 84% > >540SP2 101B 1 3338 600840 597514 600840 99% > > ------ ------ ---- > >SUMMARY 1174K 1079K 91% > >USABLE 1174K 1079K 91% > >Ready; T=0.01/0.01 10:49:56 > > > >Is this how is should be? > > > >
