HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters - HP UX

This is a discussion on HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters - HP UX ; I'm trying to multipath a LVM volume on HP-UX 11i v3 with ServiceGuard. The disks are on an EMC array, and there are two links to the disk on each of two ServiceGuard cluster nodes. One (data) disk is currently ...

+ Reply to Thread
Results 1 to 3 of 3

Thread: HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters

  1. HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters

    I'm trying to multipath a LVM volume on HP-UX 11i v3 with
    ServiceGuard. The disks are on an EMC array, and there are two links
    to the disk on each of two ServiceGuard cluster nodes.

    One (data) disk is currently configured with logical volumes and so
    forth. Attempting to use vgextend to add a second path results in:


    # vgextend -g pvg1 /dev/clvol2 /dev/dsk/c6t0d1
    Verification of unique LVM disk id on each disk in the volume group
    /dev/clvol2 failed.
    Following are the sets of disks having identical LVM disk id
    /dev/dsk/c7t0d1 /dev/dsk/c6t0d1


    What am I missing? The initial vgcreate did not have a -g option
    (that was before I knew about that option). I created /etc/lvmpvg
    with the appropriate disk in it, but the message above is what
    results.

    I don't know scsimgr, and I'm still learning ServiceGuard. What am I
    missing here?

    Thanks!

  2. Re: HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters

    David Douthitt writes:

    > I'm trying to multipath a LVM volume on HP-UX 11i v3 with
    > ServiceGuard. The disks are on an EMC array, and there are two links
    > to the disk on each of two ServiceGuard cluster nodes.
    >
    > One (data) disk is currently configured with logical volumes and so
    > forth. Attempting to use vgextend to add a second path results in:
    >
    >
    > # vgextend -g pvg1 /dev/clvol2 /dev/dsk/c6t0d1


    I think you are supposed to use the new device names ("ioscan -kfnN")

    > Verification of unique LVM disk id on each disk in the volume group
    > /dev/clvol2 failed.
    > Following are the sets of disks having identical LVM disk id
    > /dev/dsk/c7t0d1 /dev/dsk/c6t0d1


    Could it be that both devices are alternate paths to the same disk?

    >
    >
    > What am I missing? The initial vgcreate did not have a -g option
    > (that was before I knew about that option). I created /etc/lvmpvg
    > with the appropriate disk in it, but the message above is what
    > results.


    I thing PVGs are unrelated here.

    >
    > I don't know scsimgr, and I'm still learning ServiceGuard. What am I
    > missing here?


    Maybe try a pvdisplay to find out more details of the disks.
    BTW: In our environment each LUN has four paths to consider ;-)

    Ulrich

  3. Re: HP-UX 11v3, Multipathing, LVM, and ServiceGuard Clusters

    I found a lot of helpful information in the HP ITRC Forums. I'll try to
    fill in here.

    In article <87fxz77vrv.fsf@pc9454.klinik.uni-regensburg.de>,
    Ulrich.Windl@RZ.Uni-Regensburg.DE says...
    > David Douthitt writes:


    > I think you are supposed to use the new device names ("ioscan -kfnN")
    >
    > > Verification of unique LVM disk id on each disk in the volume group
    > > /dev/clvol2 failed.
    > > Following are the sets of disks having identical LVM disk id
    > > /dev/dsk/c7t0d1 /dev/dsk/c6t0d1

    >
    > Could it be that both devices are alternate paths to the same disk?


    They are - as it should be. Using pvlinks one is supposed to add the
    second disk to the volume group to activate multipathing. HP-UX 11i v3
    has intrinsic multipathing; no vgextend necessary.

    > I thing PVGs are unrelated here.


    One HP document suggested creating a physical volume group (PVG) for
    each disk. Again, though, HP-UX 11i v3 uses its intrinsic multipathing.

    > Maybe try a pvdisplay to find out more details of the disks.
    > BTW: In our environment each LUN has four paths to consider ;-)


    Same here, actually: two from cluster node 1, and two from cluster node
    2 :-P

    For seeing the new volume names, I was pointed to:

    ioscan -m dsf

    For seeing the state of LUN pathing, I was pointed to:

    scsimgr get_info -D /dev/rdisk/disk## all_lpt

    Fantastic place for HP-UX information, those ITRC Forums.... The
    relevant thread is:

    http://forums1.itrc.hp.com/service/f...r.do?threadId=
    1177297

+ Reply to Thread