Lock Disk LUN Changing

[MikeL_4]

I have a two node cluster that is using an LVM VG: /dev/vglock There are no LV's or File Systems under this VG, it's only used for the lock disk. The issue is that our SAN group here is making some changes with the SAN configuration and the LUN device for this lock disk is changing, i.e: Device c4t2d0 will be changing to c6t2d0

What steps do I need to do for this Lock VG to ensure that when the SAN work is completed my two servers in the Cluster will still be able to access this lock device ?

[Sundar_7 · Accepted solution]

Mike,

You will need to modify the cluster config and redistribute the binary to all the nodes

# cd /etc/cmcluster
# cmgetconf cluster.conf
# vi cluster.conf

Modify the cluster lock disk

# cmcheckconf -C cluster.conf
# cmapplyconf -C cluster.conf

Sundar.

[A. Clay Stephenson]

This might be an ideal time to convert to a Quorum Server rather than using a lock disk. The software is free and a little Linux box makes a dandy QS and you never have to worry about changes like this again. You will find that a QS is a better answer in all respects.

[MikeL_4]

Thanks Sundar

Clay thats for the suggestion but that isn't an option at this time within this environment.

[John Bigg]

Note that changing the cluster lock disk has to be done with the cluster halted.

And a QS does not really solve this particular problem anyway since it too would require the cluster to be halted if the QS needed to be moved to a different IP address.

The QS does have some advantages, but this is not one of them!