[Linux-cluster] Quorum question

[Bowie Bailey]

Graham Wood <mailto:gwood at dragonhold.org> wrote:
> > Can I just drop the "two_node" definition for a 3-node cluster to
> > force it to keep running with only one node?
> If you're looking at GFS, then this arrangement is almost definitely
> going to fry the data in the partition - which will take the system
> down for you permanently.
> 
> Imagine that the 3 nodes lose communication (but all three are still
> running) - they're all going to reply the logs from the other two, and
> then start writing to the shared filesystem as if they were the only
> ones in the cluster.
> 
> Which will corrupt the GFS very quickly.

Isn't that what fencing is supposed to take care of?  Maybe I'm not
understanding how this all works together.

What I will have is three nodes.  Two that actively use the data in the
shared storage and one node that handles backups.

The backup node is not critical and could be down at any time for a
number of reasons.  I want to make sure that if the backup node is down
and one of the other nodes crashes, that the one remaining node will
continue to be able to access the data in the GFS.

-- 
Bowie