disk redesign question - Veritas Volume Manager

This is a discussion on disk redesign question - Veritas Volume Manager ; Output from vxprint. Disks are in an EMC Symmetrix 8830. We are seeing high % busy for c6t17d21 to c6t17d25 from iostat. Based on different disk size below, could I have used STRIPE layout instead of CONCAT? I have a ...

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  1. disk redesign question


    Output from vxprint. Disks are in an EMC Symmetrix 8830. We are seeing
    high % busy for c6t17d21 to c6t17d25 from iostat. Based on different disk
    size
    below, could I have used STRIPE layout instead of CONCAT?
    I have a large Oracle DB (220GB)
    Filesystems for Oracle tables/indexes are mounted on the logical volumes
    vol7 to vol30. iostat shows c6t17d21-25 %busy of > 20% at anypoint in time.
    That is bad performance because the striped volumes are accessed at the
    same time, right? How should I redesign the disk architecture if I am migrating
    to DMX2000?
    Another question:
    Backend EMC (from symdev -v list and symirq) are showing that
    4210077 /dev/vx/rdmp/c6t17d21s2 07B-C-2 4210077 /dev/vx/rdmp/c6t17d21s2
    10A-C-2
    Is it true to say Veritas device c6t17d21s2 are hosted on 2 physical disks
    (LUNS?), with EMC dir ids: 07B-C-2 , 10A-C-2?
    Thank you in advance.

    Disk group: app


    dg app default default 91000 1032974724.4739.svr01


    dm app01 c6t17d9s2 sliced 1024 17674495 -
    dm app02 c6t17d8s2 sliced 1024 17674495 -
    dm app03 c6t17d7s2 sliced 1024 17674495 -
    dm app04 c6t17d25s2 sliced 1024 70704895 -
    dm app05 c6t17d24s2 sliced 1024 70704895 -
    dm app06 c6t17d23s2 sliced 1024 70704895 -
    dm app07 c6t17d22s2 sliced 1024 70704895 -
    dm app08 c6t17d21s2 sliced 1024 70704895 -
    dm app09 c6t17d67s2 sliced 2623 35349120 -
    dm app10 c6t17d41s2 sliced 3839 70700160 -
    dm app11 c6t17d42s2 sliced 3839 70700160 -


    v vol01 - ENABLED ACTIVE 3145728 SELECT -
    fsgen
    pl vol01-01 vol01 ENABLED ACTIVE 3145920 CONCAT -
    RW
    sd app03-01 vol01-01 app03 895 3145920 0 c6t17d7s2
    ENA


    v vol02 - ENABLED ACTIVE 8388608 SELECT -
    fsgen
    pl vol02-01 vol02 ENABLED ACTIVE 8389440 CONCAT -
    RW
    sd app03-02 vol02-01 app03 3146815 8389440 0 c6t17d7s2
    ENA


    v vol03 - ENABLED ACTIVE 9017344 SELECT -
    fsgen
    pl vol03-01 vol03 ENABLED ACTIVE 9018240 CONCAT -
    RW
    sd app03-03 vol03-01 app03 11536255 6138240 0 c6t17d7s2
    ENA
    sd app10-01 vol03-01 app10 0 2880000 6138240 c6t17d41
    ENA


    v vol04 - ENABLED ACTIVE 2097152 SELECT -
    fsgen
    pl vol04-01 vol04 ENABLED ACTIVE 2097600 CONCAT -
    RW
    sd app02-01 vol04-01 app02 895 2097600 0 c6t17d8s2
    ENA


    v vol05 - ENABLED ACTIVE 12582912 SELECT -
    fsgen
    pl vol05-01 vol05 ENABLED ACTIVE 12583680 CONCAT -
    RW
    sd app02-02 vol05-01 app02 2098495 12583680 0 c6t17d8s2
    ENA


    v vol06 - ENABLED ACTIVE 14680064 SELECT -
    fsgen
    pl vol06-01 vol06 ENABLED ACTIVE 14680320 CONCAT -
    RW
    sd app01-01 vol06-01 app01 895 14680320 0 c6t17d9s2
    ENA


    v vol07 - ENABLED ACTIVE 20971520 SELECT
    vol07-01 fsgen
    pl vol07-01 vol07 ENABLED ACTIVE 20976000 STRIPE 5/128
    RW
    sd app08-01 vol07-01 app08 895 4195200 0/0
    c6t17d21s2 ENA
    sd app07-01 vol07-01 app07 895 4195200 1/0
    c6t17d22s2 ENA
    sd app06-01 vol07-01 app06 895 4195200 2/0
    c6t17d23s2 ENA
    sd app05-01 vol07-01 app05 895 4195200 3/0
    c6t17d24s2 ENA
    sd app04-01 vol07-01 app04 895 4195200 4/0
    c6t17d25s2 ENA


    v vol08 - ENABLED ACTIVE 20971520 SELECT
    vol08-01 fsgen
    pl vol08-01 vol08 ENABLED ACTIVE 20976000 STRIPE 5/128
    RW
    sd app08-02 vol08-01 app08 4196095 4195200 0/0
    c6t17d21s2 ENA
    sd app07-02 vol08-01 app07 4196095 4195200 1/0
    c6t17d22s2 ENA
    sd app06-02 vol08-01 app06 4196095 4195200 2/0
    c6t17d23s2 ENA
    sd app05-02 vol08-01 app05 4196095 4195200 3/0
    c6t17d24s2 ENA
    sd app04-02 vol08-01 app04 4196095 4195200 4/0
    c6t17d25s2 ENA


    v vol09 - ENABLED ACTIVE 20971520 SELECT
    vol09-01 fsgen
    pl vol09-01 vol09 ENABLED ACTIVE 20976000 STRIPE 5/128
    RW
    sd app08-03 vol09-01 app08 8391295 4195200 0/0
    c6t17d21s2 ENA
    sd app07-03 vol09-01 app07 8391295 4195200 1/0
    c6t17d22s2 ENA
    sd app06-03 vol09-01 app06 8391295 4195200 2/0
    c6t17d23s2 ENA
    sd app05-03 vol09-01 app05 8391295 4195200 3/0
    c6t17d24s2 ENA
    sd app04-03 vol09-01 app04 8391295 4195200 4/0
    c6t17d25s2 ENA
    .....


    v vol28 - ENABLED ACTIVE 204800 SELECT
    vol28-01 fsgen
    pl vol28-01 vol28 ENABLED ACTIVE 211200 STRIPE 5/128
    RW
    sd app08-22 vol28-01 app08 70662655 42240 0/0
    c6t17d21s2 ENA
    sd app07-22 vol28-01 app07 70662655 42240 1/0
    c6t17d22s2 ENA
    sd app06-22 vol28-01 app06 70662655 42240 2/0
    c6t17d23s2 ENA
    sd app05-22 vol28-01 app05 70662655 42240 3/0
    c6t17d24s2 ENA
    sd app04-22 vol28-01 app04 70662655 42240 4/0
    c6t17d25s2 ENA


    v vol29 - ENABLED ACTIVE 56623104 SELECT -
    fsgen
    pl vol29-01 vol29 ENABLED ACTIVE 56624640 CONCAT -
    RW
    sd app09-01 vol29-01 app09 0 14680320 0
    c6t17d67s2 ENA
    sd app10-02 vol29-01 app10 2880000 41944320 14680320 c6t17d41
    ENA


    v vol30 - ENABLED ACTIVE 56623104 SELECT -
    fsgen
    pl vol30-01 vol30 ENABLED ACTIVE 56624640 CONCAT -
    RW
    sd app09-02 vol30-01 app09 14680320 20668800 0
    c6t17d67s2 ENA
    sd app11-01 vol30-01 app11 0 35955840 20668800 c6t17d42
    ENA




  2. Re: disk redesign question

    It is true that the columns in a stripe can be accessed in parallel.
    In the case where there are 2 seperate IO paths.

    In your case where all IO will go through a single controller (thus a
    single driver), it will appear that the LUNs in a stripe are used in
    parallel, but in truth, they are not.

    Volume Manager can send IO to LUNs in parallel.

    My suggestion is to have multiple paths to the disks, stripe is good.
    The size of the stripe will depend on the type of IO (oracle databases
    write in 8K blocks by default)

    Now, your question about the LUNs.

    From the symdev output, you can see that there are 2 physical disks in
    the Symm that makes up the LUN.

    A LUN (Logical Unit Number) is a single disk presented to the outside world

    To see what Veritas sees when lookign at a disk (say c6t17d21 or "app08"
    as Veritas knows it). just do the following:

    vxdisk list app08


    Look at the bottom of the output. It will show you the paths to the LUN.

    mikeli wrote:
    > Output from vxprint. Disks are in an EMC Symmetrix 8830. We are seeing
    > high % busy for c6t17d21 to c6t17d25 from iostat. Based on different disk
    > size
    > below, could I have used STRIPE layout instead of CONCAT?
    > I have a large Oracle DB (220GB)
    > Filesystems for Oracle tables/indexes are mounted on the logical volumes
    > vol7 to vol30. iostat shows c6t17d21-25 %busy of > 20% at anypoint in time.
    > That is bad performance because the striped volumes are accessed at the
    > same time, right? How should I redesign the disk architecture if I am migrating
    > to DMX2000?
    > Another question:
    > Backend EMC (from symdev -v list and symirq) are showing that
    > 4210077 /dev/vx/rdmp/c6t17d21s2 07B-C-2 4210077 /dev/vx/rdmp/c6t17d21s2
    > 10A-C-2
    > Is it true to say Veritas device c6t17d21s2 are hosted on 2 physical disks
    > (LUNS?), with EMC dir ids: 07B-C-2 , 10A-C-2?
    > Thank you in advance.
    >
    > Disk group: app
    >
    >
    > dg app default default 91000 1032974724.4739.svr01
    >
    >
    > dm app01 c6t17d9s2 sliced 1024 17674495 -
    > dm app02 c6t17d8s2 sliced 1024 17674495 -
    > dm app03 c6t17d7s2 sliced 1024 17674495 -
    > dm app04 c6t17d25s2 sliced 1024 70704895 -
    > dm app05 c6t17d24s2 sliced 1024 70704895 -
    > dm app06 c6t17d23s2 sliced 1024 70704895 -
    > dm app07 c6t17d22s2 sliced 1024 70704895 -
    > dm app08 c6t17d21s2 sliced 1024 70704895 -
    > dm app09 c6t17d67s2 sliced 2623 35349120 -
    > dm app10 c6t17d41s2 sliced 3839 70700160 -
    > dm app11 c6t17d42s2 sliced 3839 70700160 -
    >
    >
    > v vol01 - ENABLED ACTIVE 3145728 SELECT -
    > fsgen
    > pl vol01-01 vol01 ENABLED ACTIVE 3145920 CONCAT -
    > RW
    > sd app03-01 vol01-01 app03 895 3145920 0 c6t17d7s2
    > ENA
    >
    >
    > v vol02 - ENABLED ACTIVE 8388608 SELECT -
    > fsgen
    > pl vol02-01 vol02 ENABLED ACTIVE 8389440 CONCAT -
    > RW
    > sd app03-02 vol02-01 app03 3146815 8389440 0 c6t17d7s2
    > ENA
    >
    >
    > v vol03 - ENABLED ACTIVE 9017344 SELECT -
    > fsgen
    > pl vol03-01 vol03 ENABLED ACTIVE 9018240 CONCAT -
    > RW
    > sd app03-03 vol03-01 app03 11536255 6138240 0 c6t17d7s2
    > ENA
    > sd app10-01 vol03-01 app10 0 2880000 6138240 c6t17d41
    > ENA
    >
    >
    > v vol04 - ENABLED ACTIVE 2097152 SELECT -
    > fsgen
    > pl vol04-01 vol04 ENABLED ACTIVE 2097600 CONCAT -
    > RW
    > sd app02-01 vol04-01 app02 895 2097600 0 c6t17d8s2
    > ENA
    >
    >
    > v vol05 - ENABLED ACTIVE 12582912 SELECT -
    > fsgen
    > pl vol05-01 vol05 ENABLED ACTIVE 12583680 CONCAT -
    > RW
    > sd app02-02 vol05-01 app02 2098495 12583680 0 c6t17d8s2
    > ENA
    >
    >
    > v vol06 - ENABLED ACTIVE 14680064 SELECT -
    > fsgen
    > pl vol06-01 vol06 ENABLED ACTIVE 14680320 CONCAT -
    > RW
    > sd app01-01 vol06-01 app01 895 14680320 0 c6t17d9s2
    > ENA
    >
    >
    > v vol07 - ENABLED ACTIVE 20971520 SELECT
    > vol07-01 fsgen
    > pl vol07-01 vol07 ENABLED ACTIVE 20976000 STRIPE 5/128
    > RW
    > sd app08-01 vol07-01 app08 895 4195200 0/0
    > c6t17d21s2 ENA
    > sd app07-01 vol07-01 app07 895 4195200 1/0
    > c6t17d22s2 ENA
    > sd app06-01 vol07-01 app06 895 4195200 2/0
    > c6t17d23s2 ENA
    > sd app05-01 vol07-01 app05 895 4195200 3/0
    > c6t17d24s2 ENA
    > sd app04-01 vol07-01 app04 895 4195200 4/0
    > c6t17d25s2 ENA
    >
    >
    > v vol08 - ENABLED ACTIVE 20971520 SELECT
    > vol08-01 fsgen
    > pl vol08-01 vol08 ENABLED ACTIVE 20976000 STRIPE 5/128
    > RW
    > sd app08-02 vol08-01 app08 4196095 4195200 0/0
    > c6t17d21s2 ENA
    > sd app07-02 vol08-01 app07 4196095 4195200 1/0
    > c6t17d22s2 ENA
    > sd app06-02 vol08-01 app06 4196095 4195200 2/0
    > c6t17d23s2 ENA
    > sd app05-02 vol08-01 app05 4196095 4195200 3/0
    > c6t17d24s2 ENA
    > sd app04-02 vol08-01 app04 4196095 4195200 4/0
    > c6t17d25s2 ENA
    >
    >
    > v vol09 - ENABLED ACTIVE 20971520 SELECT
    > vol09-01 fsgen
    > pl vol09-01 vol09 ENABLED ACTIVE 20976000 STRIPE 5/128
    > RW
    > sd app08-03 vol09-01 app08 8391295 4195200 0/0
    > c6t17d21s2 ENA
    > sd app07-03 vol09-01 app07 8391295 4195200 1/0
    > c6t17d22s2 ENA
    > sd app06-03 vol09-01 app06 8391295 4195200 2/0
    > c6t17d23s2 ENA
    > sd app05-03 vol09-01 app05 8391295 4195200 3/0
    > c6t17d24s2 ENA
    > sd app04-03 vol09-01 app04 8391295 4195200 4/0
    > c6t17d25s2 ENA
    > ....
    >
    >
    > v vol28 - ENABLED ACTIVE 204800 SELECT
    > vol28-01 fsgen
    > pl vol28-01 vol28 ENABLED ACTIVE 211200 STRIPE 5/128
    > RW
    > sd app08-22 vol28-01 app08 70662655 42240 0/0
    > c6t17d21s2 ENA
    > sd app07-22 vol28-01 app07 70662655 42240 1/0
    > c6t17d22s2 ENA
    > sd app06-22 vol28-01 app06 70662655 42240 2/0
    > c6t17d23s2 ENA
    > sd app05-22 vol28-01 app05 70662655 42240 3/0
    > c6t17d24s2 ENA
    > sd app04-22 vol28-01 app04 70662655 42240 4/0
    > c6t17d25s2 ENA
    >
    >
    > v vol29 - ENABLED ACTIVE 56623104 SELECT -
    > fsgen
    > pl vol29-01 vol29 ENABLED ACTIVE 56624640 CONCAT -
    > RW
    > sd app09-01 vol29-01 app09 0 14680320 0
    > c6t17d67s2 ENA
    > sd app10-02 vol29-01 app10 2880000 41944320 14680320 c6t17d41
    > ENA
    >
    >
    > v vol30 - ENABLED ACTIVE 56623104 SELECT -
    > fsgen
    > pl vol30-01 vol30 ENABLED ACTIVE 56624640 CONCAT -
    > RW
    > sd app09-02 vol30-01 app09 14680320 20668800 0
    > c6t17d67s2 ENA
    > sd app11-01 vol30-01 app11 0 35955840 20668800 c6t17d42
    > ENA
    >
    >
    >


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