topic Re: Changing Cluster Lock disk in Operating System - HP-UX

Changing Cluster Lock disk

Adam Garsha — Tue, 06 Sep 2005 14:03:36 GMT

Is it possible to change the cluster lock disk in a two node cluster without downtime? If so, what are the rough steps. What about if you want the new lock disk to use a disk that is also a package data disk. Is this possible?

I have a two node cluster with a 36 GB SAN presented LUN as the cluster lock disk. I want to push the lock function to a different vg (it can be an active one right?) and I want to reclaim the 36GB for use elsewhere.

Thanks.

Re: Changing Cluster Lock disk

Steven E. Protter — Tue, 06 Sep 2005 14:10:34 GMT

See the second to last response in this thread:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=260487

Lots of good docs in it.

SEP

Re: Changing Cluster Lock disk

Mel Burslan — Tue, 06 Sep 2005 14:12:15 GMT

I am not 100% sure as we have abandoned the cluster lock disk in favor of quorum servers but you can not take out the active cluster lock while the cluster is alive. First of all after changing the cluster lock disk, you will need to recompile cluster binary which by itself requires cluster downtime.

Consider using a quorum server instead of lock disks. The qs process is a very low overhead process running on a non-cluster member node. Read the serviceguard manuals to see hot to set it up.

Re: Changing Cluster Lock disk

melvyn burnard — Wed, 07 Sep 2005 03:45:58 GMT

Changing the Cluster Lock Disc while a cluster is up is not allowed.
You must first halt the cluster, make the relevant changes in the cluster ascii file, then re-apply the binary with cmapplyconf.

Re: Changing Cluster Lock disk

Geoff Wild — Wed, 07 Sep 2005 08:43:42 GMT

No, you can't change the lock disk in a running cluster.

More info in Chapter 7. Cluster and Package Maintenance:

http://docs.hp.com/en/B3936-90079/index.html

Here's a script to check your cluster lock:

# cat chkclusterlock
#!/bin/sh
#
# script to check for existence of cluster lock
#
# gwild & tstewart

PATH=/usr/bin:/usr/sbin

if [[ `id -u` != 0 ]]
then
print "\n$0: Must be super-user to run this command."
exit 1
fi

HOST=`hostname`
DEV=`cmviewconf |sed -n -e "/$HOST/{$!N;p;}" -e h | cut -d: -f2 |grep dev|awk -F/ '{print $4}'`

if [ -c /dev/rdsk/$DEV ]
then
SIZE=`diskinfo /dev/rdsk/$DEV | grep size |awk '{print $2}'`
if [ $SIZE = "io_search failed: No match found." ]
then
echo "The disk /dev/rdsk/$DEV does NOT exist on $HOST!!!"
exit 1
fi
echo "The cluster lock disk /dev/rdsk/$DEV on $HOST is $SIZE kbytes."
exit 0
else
echo "/dev/rdsk/$DEV does not exist on $HOST!!!"
exit 1
fi

Rgds...Geoff