[Linux-cluster] CS4 U5 / recommended quorumd values for a two nodes cluster

[Marc - A. Dahlhaus [ Administration | Westermann GmbH ]]

Am Dienstag, den 25.09.2007, 14:47 +0200 schrieb Jos Vos:
> On Tue, Sep 25, 2007 at 10:37:15AM +0200, Marc - A. Dahlhaus [ Administration | Westermann GmbH ] wrote:
> 
> > Your problem lies here: expected_votes="3"
> 
> [...]
> 
> > You should calculate your votes like this:
> > ( votes % 2 ) + 1
> > 
> > So you should use this: expected_votes="2"
> 
> Oh... but the FAQ (# 18) explicitly says "nodes + 1" and gives "3"
> as the example for a two-node cluster.  And I tried it (accidently)
> with expected_votes="2" and the result was that the nodes started
> fencing each other in an endless loop.  This was solve by setting
> expected_votes="3".  This is on RHEL5. b.t.w., not RHEL4.

I was talking about FAQ cman#24 (this is what you want, right? ).
I stated the quorate math, sorry for that. It should be
"qdisc votes = nodes - 1" and "cman expected votes = votes - 1".
You could give <qdisc votes="2"> in combination with <cman
expected_votes="3"> a try then.

If that vote increment in your qdisc doesn't work, FAQ cman#23 could fix
your circular fencing problems for real in a two node cluster. But we
don't use this here at our site as we have more than two nodes.

Marc