How to recreate rootdisk-B0 - Veritas Volume Manager

This is a discussion on How to recreate rootdisk-B0 - Veritas Volume Manager ; Hello * how can I recreate the rootdisk-B0 subdisk and reattach it to a certain plex? v rootvol - ENABLED ACTIVE 8201856 ROUND - root pl rootvol-01 rootvol ENABLED ACTIVE 8201856 CONCAT - RW sd rootdisk1_2-01 rootvol-01 rootdisk1_2 0 8201856 ...

+ Reply to Thread
Results 1 to 2 of 2

Thread: How to recreate rootdisk-B0

  1. How to recreate rootdisk-B0


    Hello *

    how can I recreate the rootdisk-B0 subdisk and reattach it to a certain plex?

    v rootvol - ENABLED ACTIVE 8201856 ROUND -
    root
    pl rootvol-01 rootvol ENABLED ACTIVE 8201856 CONCAT -
    RW
    sd rootdisk1_2-01 rootvol-01 rootdisk1_2 0 8201856 0 c1t0d0
    ENA
    pl rootvol-02 rootvol ENABLED ACTIVE 8201856 CONCAT -
    RW
    sd rootmirr1_2-01 rootvol-02 rootmirr1_2 0 8201856 0 c1t3d0
    ENA

    vxdisk list c1t0d0
    ....
    iosize: min=512 (bytes) max=2048 (blocks)
    public: slice=4 offset=0 len=143339136
    private: slice=3 offset=1 len=10175
    ....

    f.e.
    vxmake sd rootdisk_2-B0 rootdisk1_2,143339136,1

    vxsd assoc rootvol-01 rootdisk_2-B0
    fails with

    vxvm:vxsd: ERROR: Subdisks are not contiguous on the same disk


    Any ideas?



  2. Re: How to recreate rootdisk-B0

    Let me explain the rootdisk-B0 subdisk first.


    If you encapsulate your boot disk, Volume Manager needs a slice (and
    some space) for the private Volume Manager configuration information
    (this is normally kept on a slice with a tag of 15 - look at prtvtoc of
    any disk under Volume Manager control).

    Biggest problem with a boto disk, is that it already contains data, and
    might not have enough space for this private region. (although you might
    not have used al 8 slices on the disk). Now, Volume Manager needs some
    space (to put into a slice) for the private data. Damn !!! Stuck !!!!


    Volume Manager needs about 1 cylinder of space for this. So where could
    it get this space ??? What about, we steal a bit (just 1 cylinder) from
    swap ????? OK, that will work, but how will Volume Manager protect this
    from not being used by any volume ???

    This is done by putting the special area (a sub-disk) so that it can not
    be used for anything else. (clever ?)


    OK, now back to your problem.

    No need to create the subdisk in the first place, but if you messed it
    up (by removing it in the first place), the best option would be to
    un-encapsulate (vxunroot) and then encapsulate again.



    Hope that helps


    titus wrote:
    > Hello *
    >
    > how can I recreate the rootdisk-B0 subdisk and reattach it to a certain plex?
    >
    > v rootvol - ENABLED ACTIVE 8201856 ROUND -
    > root
    > pl rootvol-01 rootvol ENABLED ACTIVE 8201856 CONCAT -
    > RW
    > sd rootdisk1_2-01 rootvol-01 rootdisk1_2 0 8201856 0 c1t0d0
    > ENA
    > pl rootvol-02 rootvol ENABLED ACTIVE 8201856 CONCAT -
    > RW
    > sd rootmirr1_2-01 rootvol-02 rootmirr1_2 0 8201856 0 c1t3d0
    > ENA
    >
    > vxdisk list c1t0d0
    > ...
    > iosize: min=512 (bytes) max=2048 (blocks)
    > public: slice=4 offset=0 len=143339136
    > private: slice=3 offset=1 len=10175
    > ...
    >
    > f.e.
    > vxmake sd rootdisk_2-B0 rootdisk1_2,143339136,1
    >
    > vxsd assoc rootvol-01 rootdisk_2-B0
    > fails with
    >
    > vxvm:vxsd: ERROR: Subdisks are not contiguous on the same disk
    >
    >
    > Any ideas?
    >
    >


+ Reply to Thread