Re: S85 not quite right !!

From: Hunter, Mark (Mark.Hunter_at_ANHEUSER-BUSCH.COM)
Date: 06/30/03

  • Next message: Green, Simon: "Re: Slow HMC" 
    Date:         Mon, 30 Jun 2003 11:14:35 -0500
To: aix-l@Princeton.EDU

    With maxperm at 10% but current perm at 44.9% means you have lots of memory and
    no real use for it so the system has used it to cache. min/max perm just change
    the reclaim algorithm. From your stats, the oracle dbas can use more memory for
    the SGA. What is their cache hit ratio?

    Do not set strict. It can have really nasty side effects.

    -----Original Message-----
    From: Spencer Johnson [mailto:Spencer.Johnson@2020LOG.COM]
    Sent: Monday, June 30, 2003 10:34 AM
    To: aix-l@Princeton.EDU
    Subject: Re: S85 not quite right !!

    Thanks for replies Mark / Simon,

    To answer some of your questions :

    - Disks are 50% active on average is quite good as this means layout of database
    is good.

    - Our vmtune settings are currently :

    vmtune: current values:
      -p -P -r -R -f -F -N -W
    minperm maxperm minpgahead maxpgahead minfree maxfree pd_npages maxrandwrt
     104855 209711 2 64 128 144 524288 0

      -M -w -k -c -b -B -u -l -d
    maxpin npswarn npskill numclust numfsbufs hd_pbuf_cnt lvm_bufcnt lrubucket defps
    1677691 100608 25152 1 93 1584 9 131072 1

            -s -n -S -L -g -h
    sync_release_ilock nokilluid v_pinshm lgpg_regions lgpg_size strict_maxperm
            0 0 0 0 0 0

     -t
    maxclient
    1676868

    number of valid memory pages = 2097113 maxperm=10.0% of real memory
    maximum pinable=80.0% of real memory minperm=5.0% of real memory
    number of file memory pages = 942297 numperm=44.9% of real memory

    number of compressed memory pages = 0 compressed=0.0% of real memory
    number of client memory pages = 0 numclient=0.0% of real memory
    # of remote pgs sched-pageout = 0 maxclient=80.0% of real memory

    -------- IBM have also suggest turning sync_release_ilock (s) to 1 and
    strict_maxperm (h) to 1.

    I will be shortly upgrading our Dev server to ML 11, will let you know how I get
    on.

    Spencer

    -----Original Message-----
    From: Green, Simon [mailto:Simon.Green@EU.ALTRIA.COM]
    Sent: 30 June 2003 15:29
    To: aix-l@Princeton.EDU
    Subject: Re: S85 not quite right !!

    The only problems I have experienced - other than an actual shortage of
    resources - have been due to the wrong vmtune settings. (And remember that the
    default settings are NOT good for a database.)
    It's worth considering AIO as well, but I've never had a problem with that.

    The sort of settings I use are:
    /usr/samples/kernel/vmtune -p3 -P8 -b400

    That's taken from an 8-way S7A with 8GB memory, running SAP with a 750GB
    database. It's quite busy, but has almost no paging. It's based on our
    experience and recommendations from SAP.

    If you don't have something similar - particularly the -p/-P - then take care of
    that before tackling anything else.

    When you say the disks are "only 50% busy" what do you mean? If that's either
    I/O Wait or % active then I'd say it's on the high side. What sort of disk
    subsystem do you have?

    Simon Green
    Altria ITSC Europe Ltd

    AIX-L Archive at http://marc.theaimsgroup.com/?l=aix-l
    <http://marc.theaimsgroup.com/?l=aix-l&r=1&w=2> &r=1&w=2
    AIX FAQ at http://www.faqs.org/faqs/aix-faq/ <http://www.faqs.org/faqs/aix-faq/>

    N.B. Unsolicited email from vendors will not be appreciated.

    -----Original Message-----
    From: Spencer Johnson [mailto:Spencer.Johnson@2020LOG.COM]
    Sent: 30 June 2003 14:49
    To: aix-l@Princeton.EDU
    Subject: S85 not quite right !!

    Hi list,

    I have a slight problem / issue, this is related to an 7017-S85 server,
    connected to F20 ESS. The server is a 6W - 8 GB RAM running Oracle 8.1.7.4 with
    database instance of approx. 1 TB.

    The problem is that most operations (coping files, etc) cause the system to page
    and send the CPU's into Wait state constantly, I have logged a call with IBM and
    they have
    come back with a few suggestions of changing vmtune parameters.

    Oracle is tuned to allow for 6W processors but I feel that the O/S is being
    restricted by something. The disks do not perform that much work (only 50% busy
    at max).

    The O/S is currently at 4.3.3 ML 10, but am considering going to ML 11.

    Has anyone out there had similar experiences and how have they been overcome.

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