I/O Performance from EMC DMX 3000 SAN. - Aix

This is a discussion on I/O Performance from EMC DMX 3000 SAN. - Aix ; We have a DB2 database connected to an EMC DMX 3000 SAN. Response is slow for certain queries and Topas indicates a hotspot on hdisk25 which represents physical disks on the san. iostat shows data max transfer rates of just ...

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Thread: I/O Performance from EMC DMX 3000 SAN.

  1. I/O Performance from EMC DMX 3000 SAN.


    We have a DB2 database connected to an EMC DMX 3000 SAN. Response is
    slow for certain queries and Topas indicates a hotspot on hdisk25
    which represents physical disks on the san.

    iostat shows data max transfer rates of just over 1m per second when
    the DB is under load. Also "tps" which represents physical transfers
    from disk seems to be on the high side. Is this normal behaviour?
    Should I pass this data to the Storage Team and ask them to
    investigate?


    iostat -d hdisk25 2 30

    System configuration: lcpu=8 drives=44 paths=86 vdisks=0

    Disks: % tm_act Kbps tps Kb_read Kb_wrtn
    hdisk25 0.0 0.0 0.5 0 0
    hdisk25 0.0 0.0 0.0 0 0
    hdisk25 0.0 0.0 0.0 0 0
    hdisk25 0.0 0.0 0.0 0 0
    hdisk25 0.5 0.0 0.0 0 0
    hdisk25 7.5 66.0 16.0 128 4
    hdisk25 75.0 676.0 167.5 1340 12
    hdisk25 93.5 812.0 203.0 1624 0
    hdisk25 91.0 914.0 229.0 1828 0
    hdisk25 89.0 874.0 217.5 1748 0
    hdisk25 98.5 516.0 129.5 1032 0
    hdisk25 95.5 1042.0 259.0 2084 0
    hdisk25 92.5 844.0 209.0 1688 0
    hdisk25 59.0 360.0 86.0 720 0
    hdisk25 67.5 420.0 99.5 840 0
    hdisk25 82.4 202.6 48.7 408 0
    hdisk25 68.5 375.8 92.4 752 0
    hdisk25 79.0 214.0 52.5 428 0
    hdisk25 68.0 316.0 77.0 632 0
    hdisk25 89.0 770.0 193.0 1540 0
    hdisk25 62.5 404.0 100.5 800 8
    hdisk25 0.0 12.0 3.5 0 24
    hdisk25 0.0 0.0 0.0 0 0
    hdisk25 0.0 0.0 0.0 0 0



  2. Re: I/O Performance from EMC DMX 3000 SAN.

    On Sep 8, 2:14*pm, Patrick Finnegan
    wrote:
    > We have a DB2 database connected to an EMC DMX 3000 SAN. *Response is
    > slow for certain queries and *Topas indicates a hotspot on hdisk25
    > which represents physical disks on the san.
    >
    > iostat shows data max transfer rates of just over 1m per second when
    > the DB is under load. *Also "tps" which represents physical transfers
    > from disk seems to be on the high side. *Is this normal behaviour?
    > Should I pass this data to the Storage Team and ask them to
    > investigate?
    >
    > iostat -d hdisk25 2 *30
    >
    > System configuration: lcpu=8 drives=44 paths=86 vdisks=0
    >
    > Disks: * * * *% tm_act * * Kbps * * *tps * *Kb_read* Kb_wrtn
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.5 * * * * *0 * * * * 0
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > hdisk25 * * * * *0.5 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > hdisk25 * * * * *7.5 * * *66.0 * * *16.0 * * * *128 * * * * 4
    > hdisk25 * * * * 75.0 * * 676.0 * * 167.5 * * * 1340* * * *12
    > hdisk25 * * * * 93.5 * * 812.0 * * 203.0 * * * 1624* * * * 0
    > hdisk25 * * * * 91.0 * * 914.0 * * 229.0 * * * 1828* * * * 0
    > hdisk25 * * * * 89.0 * * 874.0 * * 217.5 * * * 1748* * * * 0
    > hdisk25 * * * * 98.5 * * 516.0 * * 129.5 * * * 1032* * * * 0
    > hdisk25 * * * * 95.5 * * 1042.0 * * 259.0 * * * 2084 * * * * 0
    > hdisk25 * * * * 92.5 * * 844.0 * * 209.0 * * * 1688* * * * 0
    > hdisk25 * * * * 59.0 * * 360.0 * * *86.0 * * * *720 * * * * 0
    > hdisk25 * * * * 67.5 * * 420.0 * * *99.5 * * * *840 * * * * 0
    > hdisk25 * * * * 82.4 * * 202.6 * * *48.7 * * * *408 * * * * 0
    > hdisk25 * * * * 68.5 * * 375.8 * * *92.4 * * * *752 * * * * 0
    > hdisk25 * * * * 79.0 * * 214.0 * * *52.5 * * * *428 * * * * 0
    > hdisk25 * * * * 68.0 * * 316.0 * * *77.0 * * * *632 * * * * 0
    > hdisk25 * * * * 89.0 * * 770.0 * * 193.0 * * * 1540* * * * 0
    > hdisk25 * * * * 62.5 * * 404.0 * * 100.5 * * * *800 * * * * 8
    > hdisk25 * * * * *0.0 * * *12.0 * * * 3.5 * * * * *0 * * * *24
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0



    There is a white paper that describes optimal use of DMX SAN with
    DB2.


    http://www.emc.com/collateral/hardwa...s-with-ibm.pdf



  3. Re: I/O Performance from EMC DMX 3000 SAN.

    On Sep 8, 6:00*pm, Patrick Finnegan
    wrote:
    > On Sep 8, 2:14*pm, Patrick Finnegan
    > wrote:
    >
    >
    >
    > > We have a DB2 database connected to an EMC DMX 3000 SAN. *Response is
    > > slow for certain queries and *Topas indicates a hotspot on hdisk25
    > > which represents physical disks on the san.

    >
    > > iostat shows data max transfer rates of just over 1m per second when
    > > the DB is under load. *Also "tps" which represents physical transfers
    > > from disk seems to be on the high side. *Is this normal behaviour?
    > > Should I pass this data to the Storage Team and ask them to
    > > investigate?

    >
    > > iostat -d hdisk25 2 *30

    >
    > > System configuration: lcpu=8 drives=44 paths=86 vdisks=0

    >
    > > Disks: * * * *% tm_act * * Kbps * * *tps * *Kb_read * Kb_wrtn
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.5 * * * * *0 * * * * 0
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > > hdisk25 * * * * *0.5 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > > hdisk25 * * * * *7.5 * * *66.0 * * *16.0 * * * *128 * * * * 4
    > > hdisk25 * * * * 75.0 * * 676.0 * * 167.5 * * * 1340 * * * *12
    > > hdisk25 * * * * 93.5 * * 812.0 * * 203.0 * * * 1624 * * * * 0
    > > hdisk25 * * * * 91.0 * * 914.0 * * 229.0 * * * 1828 * * * * 0
    > > hdisk25 * * * * 89.0 * * 874.0 * * 217.5 * * * 1748 * * * * 0
    > > hdisk25 * * * * 98.5 * * 516.0 * * 129.5 * * * 1032 * * * * 0
    > > hdisk25 * * * * 95.5 * * 1042.0 * * 259.0 * * * 2084 * * * * 0
    > > hdisk25 * * * * 92.5 * * 844.0 * * 209.0 * * * 1688 * * * * 0
    > > hdisk25 * * * * 59.0 * * 360.0 * * *86.0 * * * *720 * * * * 0
    > > hdisk25 * * * * 67.5 * * 420.0 * * *99.5 * * * *840 * * * * 0
    > > hdisk25 * * * * 82.4 * * 202.6 * * *48.7 * * * *408 * * * * 0
    > > hdisk25 * * * * 68.5 * * 375.8 * * *92.4 * * * *752 * * * * 0
    > > hdisk25 * * * * 79.0 * * 214.0 * * *52.5 * * * *428 * * * * 0
    > > hdisk25 * * * * 68.0 * * 316.0 * * *77.0 * * * *632 * * * * 0
    > > hdisk25 * * * * 89.0 * * 770.0 * * 193.0 * * * 1540 * * * * 0
    > > hdisk25 * * * * 62.5 * * 404.0 * * 100.5 * * * *800 * * * * 8
    > > hdisk25 * * * * *0.0 * * *12.0 * * * 3.5 * * * * *0 * * * *24
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0
    > > hdisk25 * * * * *0.0 * * * 0.0 * * * 0.0 * * * * *0 * * * * 0

    >
    > There is a white paper that describes optimal use of DMX SAN with
    > DB2.
    >
    > http://www.emc.com/collateral/hardwa...41-emc-dmx-dis...


    Hi,

    what is storage configuration - what RAID? On how many disks?
    Performance depends of many factors, e.g. what is overal DMX load? Ask
    storage team to give you these info. Do you know nmon tool? Us this
    one and show us results...

    Regards,
    Blazej

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