[Linux-cluster] GFS on SAN, does a quorum make sense?

[David Teigland]

On Fri, May 06, 2005 at 02:22:42PM -0400, Greg Freemyer wrote:

> You could designate a single "master node" that had N+1 votes.
> 
> Anytime it was online and part of the cluster, and of the other nodes
> could come and go as they please.
> 
> Unfortunately, if it ever goes offline, you lose all access to the
> shared storage.
> 
> If you made your "master node" be a low-cost but reliable node that
> had zero job responsibility besides being the master, it should be
> able to stay up for very long periods of time.

Yes, if you had seven nodes b1-b7, you could give b1 7 votes and everyone
else 1 vote.  Total votes would be 13 and quorum would require 7 or more
votes.  So as long as b1 was a member of the cluster (with its 7 votes),
there would be quorum and others could do whatever they like.

As you say, to reduce the likelihood of b1 failing you may want to just
have it join the cluster and do nothing else.

Dave