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05127 - Page Faults - Anyway to reduce SAP Storage to Reduce Page Faults

05127 - Page Faults - Anyway to reduce SAP Storage to Reduce Page Faults

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Page Faults - Anyway to reduce SAP Storage to Reduce Page Faults

Hi,

I'm just curious about LPAR. Why would would find it necessary to
LPAR your machine w/ TST & PRD? I know this is becoming common
practice, but I have been curious as to the justifications for this.

It seems to me in your situation, that you are just restricting 3 gig
of memory and 2 processors that would normally be available to PRD
when TST is not being used. (hence, the performance hit)

Our latest discussions with IBM on a replacement for our S20/S30
machines included a senario with an LPAR'd machine and I wondering
what the advantages of LPARing are.

Thanks,

Phillip Pugh
Webco Industries, Inc.

--- In SAP on System iZy..., franco.tassoneZe... wrote:
>
> Hi all,
>
> in the recent days we had a similiar problem on our iSeries 830
with two
> lpar, V5R1M0 and R/3 4.0B, the storage is driven by an IBM ESS
Shark.
> Before partitioning we had two instances on the same 830 w/o lpar
(Prod. +
> Test), the machine itself was connected via SCSI to the Shark and
the
> performances seemed to be good.
> Now we have two lpar's on our iSeries:
>
> 1. Productive lpar, 6 processors + 9Gbytes memory, fiber channel
connection
> to the ESS, machine memory pools as follow:
> 450,00 335,56 +++++ *MACHINE
> 8337,25 47,19 150 *BASE
> 0,25 0,00 1 *SPOOL
> 50,00 0,00 20 *INTERACT
>
> 2. Test lpar, 2 processors + 3Gbytes memory, scsi connection to the
ESS,
> machine memory pools as follow:
> 264,77 169,44 +++++ *MACHINE
> 2581,08 0,32 70 *BASE
> 0,34 0,00 2 *SPOOL
> 149,79 0,00 20 *INTERACT
>
> SAP performances are unbelievable bad on our productive lpar, lots
of DB
> page faults with peaks of 2000 and more per seconds.
> Maybe we have oversized any of the buffer, paging or EM ?
> Any hints ? I can send the ST02 screenshot, if you want.
> Thanks in advance.
>
> --------------------------------------------------------------------
--------
>
> Franco Tassone - (Emsar IS) tel.: +39-085-4442248
> --------------------------------------------------------------------
--------
>
>
>
>
>
>

> "Gueldenpfennig,

> Volker"
To: "'blakebrayZp...'" <blakebrayZp...>
> <volker.gueldenpfenni cc: "Sap400 (E-
mail)" <sap400Zm...>
> gZs...> Subject: RE:
Page Faults - Anyway
> to reduce SAP
Storage to Reduce Page Faults
> 18/02/02
17.19

>

>

>
>
>
>
> Hi,
>
> the amount of memory depends on the usage of the DB-server. Do you
run
> workload on the DB-server or don't you run workload at all there ?
> Normally a bit oversized buffers or EM don't increase the page-
faults as
> this is then not used as well and paged out.
>
> Could you send over a screenshot of ST02 on the DB-server after a
few days
> running ?
>
> Regards
>
> Volker
>
> > -----Original Message-----
> > From: bfbray [mailto:blakebrayZp...]
> > Sent: Montag, 18. Februar 2002 17:06
> > To: SAP on System iZy...
> > Subject: Page Faults - Anyway to reduce SAP
Storage to
> > Reduce Page Faults
> >
> >
> > Our DB Server is a 9406-730 with 13gig memory. We have all users
> > logging on to two app servers, we try not to have any users on
the DB
> > server. Our DB server 3 memory pools, *Machine=1gig,
*base=11.9gig,
> > *spool=.1gig. We basically have 12gig in *BASE which runs SAP. Our
> > Non-DB page faults average 200-400 per second (via wrksyssts) and
> > will sometimes peak 1000-2000 per second. I've read in various
notes
> > and manuals that the SAP memory definitions such as Program
Buffer,
> > Paging Area, Extended Memory, Number of WP's do not affect System
> > Performance. Is this a true or did I just misunderstand what I've
> > seen? Are there SAP buffers or other setting which I may have
> > oversized and is causing the high Non-DB page faults? The sizing
> > tools we've used indicates 12gig should enough. Before we go and
> > purchase more memory we'd like to know if something can be
cahnged to
> > reduce the amount of memory we are currently using. How much
memory
> > are others running on the DB server?
> >
> >
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