Re: [Linux-cluster] A few GFS newbie questions: journals, etc

[Lon Hohberger <lhh redhat com>]

On Tue, 2005-06-28 at 10:08 -0500, Nate Carlson wrote:
> On Mon, 27 Jun 2005, Patrick Caulfield wrote:
> > Yes, you can force expected_votes to be an unreasonable low value. 
> > Personally I set it to 1 on my single-machine Xen test cluster but then 
> > I don't care about data corruption ;-)
> 
> One thing I've noticed with this - it seems that as machines join the 
> cluster, expected_votes is automatically raised. (IE, I can start a single 
> node and have it gain quorum, but if I join another node and then leave 
> the cluster, the first one loses quorum - if I manually drop the expected 
> vots with cman_tool, then it gains quorum again.) Is that expected 
> behavior? I'd expect manually specifying expected_votes to lock it down.

It's expected behavior.

The quorum calculation algorithm is specifically designed to prevent
what you're doing.  The expected_votes is counted at startup, but grows
dynamically after that.  The only time where it doesn't grow is in the
"two_node=1" case.

-- Lon