Veritas DMP use with Oracle ASM - Veritas Volume Manager

This is a discussion on Veritas DMP use with Oracle ASM - Veritas Volume Manager ; I would like to use the DMP metanodes for I/O using Oracle's Automated Storage Management. I am talking about the /dev/vx/rdmp/* devices that Veritas uses to multipath all I/O's to the disks. The problem is that the devices are protected ...

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Thread: Veritas DMP use with Oracle ASM

  1. Veritas DMP use with Oracle ASM



    I would like to use the DMP metanodes for I/O using Oracle's Automated Storage
    Management. I am talking about the /dev/vx/rdmp/* devices that Veritas uses
    to multipath all I/O's to the disks. The problem is that the devices are
    protected and only root can read and write to them. This is a problem since
    the Oracle database runs as oracle. I know I can set up a volume group and
    create a volume and provide this to Oracle to use but this is not recommended
    by Oracle. ASM is designed to directly access the RAW disk devices (/dev/rdsk).


    I have Veritas on several Sun Solaris systems for use with a variety of SAN
    disk arrays (EMC, StorageTek) and am happy with the array types it supports.
    My only options for multipathing with ASM appear to be Powerpath and Solaris
    built in multipathing.

    I know the DMP devices should be protected but having them accessible for
    Oracle solves a bunch of my problems. Right now I have my databases running
    as root to test ASM with the dmp metanodes. Any way to get oracle read /
    write access to these devices?

    Thanks.

    Will

  2. Re: Veritas DMP use with Oracle ASM


    Will,
    I have exactly the same problem and question. Oracle point to Veritas and
    Veritas say use volume manager to encapsulate the disks.
    I agree it is an ownership/permissions issue. I tried changing both appropriately
    on the /dev/vx/rdmp/c* devices but when I tried to add tehm to ASM I keep
    getting ownersip/permission errors.
    If I reference one path or the other with /dev/rdsk/c* it works fine.
    If you have an answer to this already I would be excremely grateful to hear
    it. If I find an answer I will post it.
    Jay

  3. Re: Veritas DMP use with Oracle ASM


    Did you set the owner to "oracle" ?

    If you did and there is still a perm problem, log in as oracle and test what
    hpappens when you do a 'dd if=/dev/vx/rdmp/cxxx of=/dev/null'. You should
    get an error.

    If so, then it is probably a perm issue on "/dev/vx" and/or "/dev/vx/dev/vx"
    add a o+r and o+x to those directories and see what happens when you do
    the 'dd' as oracle user.

    bv

  4. Re: Veritas DMP use with Oracle ASM



    Jay,

    The only possible solution I have is to use MPxIO to do the failover for
    the disks. MPxIO created 1 device entry for each disk that ASM can see.
    I have not fully tested this configuration and do not know if oracle will
    be able to handle the large device names generated by MPxIO. I have no indication
    Veritas DMP can be used with ASM.

    Will

    "Jay Joshi" wrote:
    >
    >Will,
    >I have exactly the same problem and question. Oracle point to Veritas and
    >Veritas say use volume manager to encapsulate the disks.
    >I agree it is an ownership/permissions issue. I tried changing both appropriately
    >on the /dev/vx/rdmp/c* devices but when I tried to add tehm to ASM I keep
    >getting ownersip/permission errors.
    >If I reference one path or the other with /dev/rdsk/c* it works fine.
    >If you have an answer to this already I would be excremely grateful to hear
    >it. If I find an answer I will post it.
    >Jay



  5. Re: Veritas DMP use with Oracle ASM


    Any progress on this? I have the exact same issue, and not just for ASM.
    If you try
    to use Oracle with raw devices you get the same problem. It can't do any
    I/O to the
    /dev/vx/rdmp/c* files even if you chmod/chown them.

    Eric

    "Will Robinson" wrote:
    >
    >
    >Jay,
    >
    >The only possible solution I have is to use MPxIO to do the failover for
    >the disks. MPxIO created 1 device entry for each disk that ASM can see.
    > I have not fully tested this configuration and do not know if oracle will
    >be able to handle the large device names generated by MPxIO. I have no

    indication
    >Veritas DMP can be used with ASM.
    >
    >Will
    >
    >"Jay Joshi" wrote:
    >>
    >>Will,
    >>I have exactly the same problem and question. Oracle point to Veritas

    and
    >>Veritas say use volume manager to encapsulate the disks.
    >>I agree it is an ownership/permissions issue. I tried changing both appropriately
    >>on the /dev/vx/rdmp/c* devices but when I tried to add tehm to ASM I keep
    >>getting ownersip/permission errors.
    >>If I reference one path or the other with /dev/rdsk/c* it works fine.
    >>If you have an answer to this already I would be excremely grateful to

    hear
    >>it. If I find an answer I will post it.
    >>Jay

    >



  6. Re: Veritas DMP use with Oracle ASM


    Create a diskgroup, add the desired disk
    Create a volume with max. size
    Use /dev/vx/rdsk// as RAW DMP device
    with us it works...


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