[Linux-cluster] Using LABEL in "Device Special File" as a resource

[Celso K. Webber]

Hello Tarun,

I had to solve this problem once under RHEL AS v2.1 (first version of Cluster
Manager), and it worked perfectly. By that time my problem was that the
machines had different internal disk configurations, so they had differente
"/dev/sdXX" names.

Under Cluster Suite v3 I solved this problem by pointing the real devices to
raw devices, and /dev/raw/XXX after that. I don't know if this has
implications on performance, but the systems worked apparently well.

I had once some problems with iSCSI on a IBM Blade Center where the iSCSI
volumes changed their /dev/XXX if the machine booted with the USB floppy/cdrom
connected (iSCSI dev was /dev/sdb with no USB floppy, but it was recognized as
/dev/sdc if the USB floppy was connected when the machine booted).
Fortunately, it was a regular filesystem (no cluster) and I could use
LABEL=XXX entries in /etc/fstab.

By this time I cannot figure out how could you solve your problem. I imagine
that it should not be difficult to write a Perl or Shell script that ran just
before the clumanager started, and issuing commands such as "iscsi-ls" it
could map a corresponding raw device, or even changing your /etc/cluster.xml
on the fly and writing it to the quorum using a "cludb" command.

Sorry for not pointing out a better solution, ok?

Regards,

Celso.

On Sun, 26 Mar 2006 18:02:46 -0700, Tarun Reddy wrote
> Hmmm....
> 
> I guess I never tried to edit cluster.xml by hand. On my system at  
> least, redhat-config-cluster does not allow the value. I'll try  
> editing cluster.xml tomorrow and see if that works. Could  you let 
> me  know if you can get redhat-config-cluster to accept the LABEL  
> designation? Could it possibly be that my LABEL is "/www" (no quotes)?
> 
> Thanks,
> Tarun
> 
> On Mar 24, 2006, at 10:01 AM, Lon Hohberger wrote:
> 
> > On Thu, 2006-03-23 at 14:50 -0700, Tarun Reddy wrote:
> >> -----BEGIN PGP SIGNED MESSAGE-----
> >> Hash: SHA1
> >>
> >> Under RHEL3 clustering, I'm trying to mount a partition using the
> >> LABEL since iscsi bindings have a tendency to switch around.
> >>
> >> Using Google to search the archives, I found this message:
> >> http://www.redhat.com/archives/linux-cluster/2005-October/ 
> >> msg00129.html
> >>
> >> but this doesn't seem to work with Redhat Clustering on RHEL3. Is
> >> there another way of doing this?
> >
> > It really should work; it works on my RHEL3 system:
> >
> > [root at magenta root]# e2label /dev/sdd3
> >
> > [root at magenta root]# e2label /dev/sdd3 futon
> > [root at magenta root]# e2label /dev/sdd3
> > futon
> > [root at magenta root]# vi /etc/cluster.xml
> > ...
> >     <service checkinterval="10" id="0" name="foo">
> >       <device id="0" name="LABEL=futon" sharename="">
> >                <!--   ^- name used to be /dev/sdd3 -->
> >         <mount forceunmount="yes" fstype="ext3" mountpoint="/mnt/1"
> > options=""/>
> >       </device>
> >       ...
> >     </service>
> > ...
> >
> > Starting the service and running the mount command yielded this on my
> > machine:
> >
> > [root at magenta root]# mount
> > ...
> > /dev/sdd3 on /mnt/1 type ext3 (rw)
> > ...
> >
> > Stopping the service causes the mount to go away correctly on my  
> > system.
> > The label->device resolution has not changed since before the  
> > release of
> > RHCS3, so there must be something missing that we don't know about.
> > Note that "LABEL" is case-sensitive, and must be all capital letters,
> > and that no spaces are allowed.
> >
> > -- Lon
> >
> > --
> > Linux-cluster mailing list
> > Linux-cluster at redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-cluster
> 
> --
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> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster


--
Celso K. Webber <celso at webbertek.com.br>
(41) 3284-3035
(41) 8813-1919