AIX + Oracle ASM + EMC Symmetrix - low performance - Aix

This is a discussion on AIX + Oracle ASM + EMC Symmetrix - low performance - Aix ; Hello all, we have bought p570 machine with AIX 5.3 system. It's already configured etc, but.. we have very low database performance with this configuration. We are using EMC Symmetrix (without powerpath!), Oracle 10 Database with ASM. We have tried ...

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Thread: AIX + Oracle ASM + EMC Symmetrix - low performance

  1. AIX + Oracle ASM + EMC Symmetrix - low performance

    Hello all,

    we have bought p570 machine with AIX 5.3 system. It's already configured
    etc, but.. we have very low database performance with this configuration.
    We are using EMC Symmetrix (without powerpath!), Oracle 10 Database
    with ASM.

    We have tried with rhdisk devices (raw devices) and LVM volumes
    for ASM subsystem - both without success...
    We have tried to tune AIX (ie using this document
    http://www-03.ibm.com/support/techdo...Index/WP100708
    also without success. The database is very slow.

    Does anyone is using ASM for Oracle with AIX?

    regards,

    Sierp

  2. Re: AIX + Oracle ASM + EMC Symmetrix - low performance

    On Thu, 21 Jun 2007 15:03:52 +0200, Sierp wrote:

    > Hello all,
    >
    > we have bought p570 machine with AIX 5.3 system. It's already configured
    > etc, but.. we have very low database performance with this
    > configuration. We are using EMC Symmetrix (without powerpath!), Oracle
    > 10 Database with ASM.
    >
    > We have tried with rhdisk devices (raw devices) and LVM volumes for ASM
    > subsystem - both without success... We have tried to tune AIX (ie using
    > this document
    > http://www-03.ibm.com/support/techdo...Index/WP100708
    > also without success. The database is very slow.
    >
    > Does anyone is using ASM for Oracle with AIX?
    >
    > regards,
    >
    > Sierp


    I'm not a DBA, but ours have been trying to set this up on a slightly
    different configuration (same servers, different storage array) in order
    to support RAC, and have been having a lot of problems with it.
    According to them, even Oracle doesn't run ASM internally, so it's
    something of a stepchild. They have decided to go a different route. So
    we have not gotten to the point of even being able to try performance,
    and have had issues.

  3. Re: AIX + Oracle ASM + EMC Symmetrix - low performance

    On Jun 21, 6:43 am, "F. Michael Orr" wrote:
    > On Thu, 21 Jun 2007 15:03:52 +0200, Sierp wrote:
    > > Hello all,

    >
    > > we have bought p570 machine with AIX 5.3 system. It's already configured
    > > etc, but.. we have very low database performance with this
    > > configuration. We are using EMC Symmetrix (without powerpath!), Oracle
    > > 10 Database with ASM.

    >
    > > We have tried with rhdisk devices (raw devices) and LVM volumes for ASM
    > > subsystem - both without success... We have tried to tune AIX (ie using
    > > this document
    > >http://www-03.ibm.com/support/techdo...Index/WP100708
    > > also without success. The database is very slow.

    >
    > > Does anyone is using ASM for Oracle with AIX?

    >
    > > regards,

    >
    > > Sierp

    >
    > I'm not a DBA, but ours have been trying to set this up on a slightly
    > different configuration (same servers, different storage array) in order
    > to support RAC, and have been having a lot of problems with it.
    > According to them, even Oracle doesn't run ASM internally, so it's
    > something of a stepchild. They have decided to go a different route. So
    > we have not gotten to the point of even being able to try performance,
    > and have had issues.- Hide quoted text -
    >
    > - Show quoted text -


    I run this setup with powerpath -- AND get the latest oracle
    patches-- it is incredibly buggy-- and have aix53-04-CSP at least.

    Performance is OK but how do you keep track of the disks? it is very
    hard to tell with ASM and LVM ( we also have VxVM/CFS so its even
    worse) -- lspv won't be right ; pvid's are meaningless ; I use EMC
    lun IDs to track disks across nodes.

    DBA's don't like ASM either because it has them interacting with the
    hardware more than they want to. We are looking at replacing ASM
    with veritas CFS for concurrent access filesystems; juts so we can
    mange the disks better.

    things like adding and removing disks become a noightmare -- scsi
    reserve bits get reset and the db won't come up on one node-- hard to
    diagnose that until you've done it.

    ASM needs a much better admin tool before it will be usable in the
    world.



  4. Re: AIX + Oracle ASM + EMC Symmetrix - low performance

    jthomp1515@yahoo.com pisze:
    > I run this setup with powerpath -- AND get the latest oracle
    > patches-- it is incredibly buggy-- and have aix53-04-CSP at least.
    >
    > Performance is OK but how do you keep track of the disks? it is very
    > hard to tell with ASM and LVM ( we also have VxVM/CFS so its even
    > worse) -- lspv won't be right ; pvid's are meaningless ; I use EMC
    > lun IDs to track disks across nodes.


    did you tune AIX/Oracle in some special way?

    about keeping track - without a problem... We have one LUN
    (which can be checked with lsattr -El hdiskx and pvid field)
    and two LVs on this specific hdisk. So we do know, which LV
    is on which LUN. This is not the case really.

    The problem is performance...

    Sierp

  5. Re: AIX + Oracle ASM + EMC Symmetrix - low performance

    On Thu, 21 Jun 2007 21:11:34 +0200, Sierp wrote:

    > jthomp1515@yahoo.com pisze:
    >> I run this setup with powerpath -- AND get the latest oracle
    >> patches-- it is incredibly buggy-- and have aix53-04-CSP at least.
    >>
    >> Performance is OK but how do you keep track of the disks? it is very
    >> hard to tell with ASM and LVM ( we also have VxVM/CFS so its even
    >> worse) -- lspv won't be right ; pvid's are meaningless ; I use EMC
    >> lun IDs to track disks across nodes.

    >
    > did you tune AIX/Oracle in some special way?
    >
    > about keeping track - without a problem... We have one LUN
    > (which can be checked with lsattr -El hdiskx and pvid field)
    > and two LVs on this specific hdisk. So we do know, which LV
    > is on which LUN. This is not the case really.
    >
    > The problem is performance...
    >
    > Sierp


    I can't tell you how heavily it's hit, but we have ASM running in a VIO
    client environment. It seems to work fine, but I agree. It's a major
    pain to figure out what's going where. Putting it in with HACMP is going
    to be another really interesting challenge...

    For semi-political reasons, the VIO clients with the database instances
    are AIX 5.3 ML3, and the VIO server is running code from more than a year
    ago too... That means we can't tweak the disk queue depth at all.

    I tried putting the ASM volume under LVM control, but the DBA hat a fit
    and made me put it all on raw disks... Running any kind of Oracle
    database on only one disk device will probably give you bad performance.

    Has your DBA run the Oracle performance analysis tools to look for the
    slow-down points?

    -Chris

  6. Re: AIX + Oracle ASM + EMC Symmetrix - low performance

    Christopher Petersen a écrit :
    > On Thu, 21 Jun 2007 21:11:34 +0200, Sierp wrote:
    >
    >> jthomp1515@yahoo.com pisze:
    >>> I run this setup with powerpath -- AND get the latest oracle
    >>> patches-- it is incredibly buggy-- and have aix53-04-CSP at least.
    >>>
    >>> Performance is OK but how do you keep track of the disks? it is very
    >>> hard to tell with ASM and LVM ( we also have VxVM/CFS so its even
    >>> worse) -- lspv won't be right ; pvid's are meaningless ; I use EMC
    >>> lun IDs to track disks across nodes.

    >> did you tune AIX/Oracle in some special way?
    >>
    >> about keeping track - without a problem... We have one LUN
    >> (which can be checked with lsattr -El hdiskx and pvid field)
    >> and two LVs on this specific hdisk. So we do know, which LV
    >> is on which LUN. This is not the case really.
    >>
    >> The problem is performance...
    >>
    >> Sierp

    >
    > I can't tell you how heavily it's hit, but we have ASM running in a VIO
    > client environment. It seems to work fine, but I agree. It's a major
    > pain to figure out what's going where. Putting it in with HACMP is going
    > to be another really interesting challenge...
    >
    > For semi-political reasons, the VIO clients with the database instances
    > are AIX 5.3 ML3, and the VIO server is running code from more than a year
    > ago too... That means we can't tweak the disk queue depth at all.
    >
    > I tried putting the ASM volume under LVM control, but the DBA hat a fit
    > and made me put it all on raw disks... Running any kind of Oracle
    > database on only one disk device will probably give you bad performance.
    >
    > Has your DBA run the Oracle performance analysis tools to look for the
    > slow-down points?
    >
    > -Chris

    We have been running Oracle RAC 10.2.0.1 and 10.2.0.3 + ASM for over a
    year now and it's blazing fast. We are using HDS+cisco for storage and 4
    * 4 cpus P570 mahines.

    We have been working closely with IBM/Oracle lab in Aix en Provence, and
    they say that running ASM through VIO is not supported (should be at the
    end of 2007). Doing so will give poor IO performence. We have therefore
    dedicated FC cards to each LPAR running Oracle. It is also very strongly
    recommended that you use dedicated GigaEthernet cards for the Oracle RAC
    internal link.

    By the way we don't feel any difficulty in having ASM handling disk
    access. I'd rather say it's made things easier.

    I'm afraid that you are probably facing some Oracle setup problem or a
    poorly designed database. As Oracle's performance guide states it:
    Database performance is mainly achieved by design. And switching from
    ASM to something else won't probably make a big difference.

    Anyhow you should take a look at what AWR and ADDM reports are telling
    about it ?

    Maybe something helpfull in what I wrote.

    Good night (and luck) :-D

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