If there are 3 node,is it necessary to set a lock-disk for the MS?

[Rambo_1]

Thanks

[Carsten Krege]

On a 3 node SG cluster, you don't need a cluster lock disk, however, it is strongly recommended.

Imagine the following situation: You have one node down for maintenance (reboot or so), then the other two nodes reform, e.g. because the heartbeat connection is down. Since none of the nodes has quorum, they need to access the lock disk, but if there is none configured, both nodes will reboot (perform a TOC).

So, there is no problem if all 3 nodes are running in the cluster, the problem will show up if only 2 nodes are running. THese are basically unprotected then.

Carsten

[Rita C Workman]

Just to add...it is only when you go past 4 nodes, that the lockdisk is no longer created.

Rgrds,
Rita

[Geoff Wild]

It is highly recommended...but, you can consider using a qurom server instead.

See:

http://docs.hp.com/hpux/onlinedocs/B3936-90079/B3936-90079.html

In particular, read section on "Setting up the Quorum Server " under "Building an HA Cluster Configuration "

Rgds...Geoff