[Linux-cluster] Starting a cluster - Quorum Numbers

[James Parsons]

Jonathan E Brassow wrote:

> You must achieve quorum before the cluster services are enabled.  That 
> means 1/2 of your machines listed in cluster.conf +1 must come up.
>
> After that, if you do a 'cman_tool leave remove' on the machines you 
> don't need, you should be able to go down as low as you want.  (I 
> think there is a way to make the cman initscript do this 
> automatically...  I also think you can specify a node count or quorum 
> number in cluster.conf to control when it's allowed to start the 
> service - but this last one might be unlikely, given that it could 
> lead to split-brain.)
>
I am sorry if this sounds like another commercial announcement, but 
Conga will allow you to control which nodes are joined or out of the 
cluster very easily. It also display necessary quorum, and what the 
total votes in the cluster currently is. Conga runs on RHEL5 and will 
also be in the RHEL4 Update 5 distribution -- it will run OK on all of  
RHEL4 generally.

My intention here is not to schill, but rather to announce that there is 
an alternative in place for the need to ssh around the cluster and exec 
specific commands with specific args. *shrug*

-J