Re: [linux-lvm] Re: alternate link / multi-pathing

["C'est Pierre" <cestpierre@gmail.com>]

Hello Luca,

Thanks for pointing me that out, too bad it's a bit late, since the
server is now crashed and only tomorrow I will be able to reset it.
Meanwhile, I've got a few questions for you:

1. How do I disable raid autodetect ?
2. Where can I read about device-mapper-multipath ?
3. To deactivate the vg, I suppose I should use vgchange -a n, correct
me if I am wrong

Thank you for your reply!
Gon�alo


On 5/28/06, Luca Berra <bluca@comedia.it> wrote:
> On Sun, May 28, 2006 at 02:50:24AM +0100, C'est Pierre wrote:
> >Nevermind about my previous question! I just made my way into this
> >page:
> >http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/s390-multi-install-guide/s1-s390info-raid.html
> >and have setup the multipathing nicely.
>
> actually the device-mapper-multipath would a better approach than
> md-multipath
>
> >However, I went into the second node (this is 2 nodes failover cluster
> >environment) and I noticed that the vg and the md0 appeared there
> >there automatically! is this normal? is there anything I should do?
>
> it is not normal
> it should not happen
>
> if you insist in using md multipath, ensure raid autodetect won't pick
> it up.
> i.e. disable damned autodetect on kernel command line or
> change the partition type to something different than 'Linux Raid'
>
> then you'll have to ensure that your distribution  init scripts do not
> automatically start it.
> best way is omitting this set entries from /etc/mdadm.conf
> and putting it somewhere else, then invoking
> "mdadm -Asc /some/where/else/mdadm.conf" in your cluster script
>
> if you use device-mapper-multipath (which might also solve the issue in
> your next post :)
> there is no problem if multipath finds the devices on the failover node,
> but you must prevent lvm from activating the vg
>
> to do this either add cluster locking or use tags, as explained in the
> doc/tagging.txt files in the lvm distribution
>
> Regards,
> L.
>
>
> --
> Luca Berra -- bluca@comedia.it
>         Communication Media & Services S.r.l.
>  /"\
>  \ /     ASCII RIBBON CAMPAIGN
>   X        AGAINST HTML MAIL
>  / \
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>