[Linux-cluster] expected_votes meaning

[Claudio Tassini]

You said that quorum is (expected_votes/2)+1 , which means 7/2=3.5+1=
4.5... is it rounded up or down?

2007/8/31, Patrick Caulfield <pcaulfie at redhat.com>:
>
> Claudio Tassini wrote:
> > Hi all,
> >
> > this could sound quite obvious but I really can't find a reference guide
> > to cluster.conf parameters. What is the exact meaning of the
> > expected_votes cman attribute ?  Is it the total number of votes on
> > which cman calculates the quorum needing of a member or is it the actual
> > number of votes needed by a member to boot?
>
> expected_votes is the total number of votes in a fully functional cluster.
> Quorum is calculated from this as (half the number of expected_votes)+1.
> when
> the cluster has fewer than quorum votes then services will stall.
>
>
> > I'll try to explain: 4-nodes cluster. 1 vote per node. 1 quorum disk
> > with 3 votes. expected_votes set to 7 as read in the cluster faq. The
> > faq says that every single node should be able to remain in the cluster
> > as long as it can reach the quorum, with a total vote count of 4 (3 for
> > the quorum, 1 for the node itself), which is claimed to be enough with
> > an expected_votes of 7. This is why I'm quite confused... if
> > expected_votes is 7, doesn't this mean that the "1 node+qdisk" vote
> > count should be 7 to prevent quorum being dissolved?
>
> So, in your system expected_votes is 7, quorum is 4. so any 1 node + the
> quorum
> disk will be a valid cluster. Which sounds sensible :)
>
> Patrick
>
> --
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster
>



-- 
Claudio Tassini
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/linux-cluster/attachments/20070831/5fc7ff6f/attachment.htm>