[Linux-cluster] How to disable node?

[John Ruemker]

On 08/31/2009 04:30 PM, Jakov Sosic wrote:
> Hi.
>
> I have a problem that one of my 3 nodes is sent to RMA to hardware
> dealer. I want to know is it possible to disable that one node, because
> clurgmgrd is not starting any services because cman is unable to fence
> the missing node...
>
> Aug 31 22:02:14 node03 fenced[5082]: fence "node02" failed
> Aug 31 22:02:19 node03 fenced[5082]: fencing node "node02"
> Aug 31 22:04:38 node03 fenced[5082]: agent "fence_ipmilan" reports:
> Rebooting machine @ IPMI:x.y.z.w...ipmilan: Failed to connect
> after 30 seconds Failed
>

The best course of action to take would be to remove that missing node 
from your cluster configuration using conga, system-config-cluster, or 
by hand editing /etc/cluster/cluster.conf.  As long as it exists in the 
configuration then the other nodes will expect it to join the cluster, 
and they will attempt to fence it when they try to join the cluster and 
see it is not present.  When you remove it from the configuration by 
hand, you will also want to set two_node="1 and expected_votes="1" in 
the cman tag like so

    <cman two_node="1" expected_votes="1"/>

If you are using one of the graphical tools these options should be 
added for you.  They ensure that if one of your remaining two nodes 
dies, the one that is left can maintain quorum by itself.

After making these changes and propagating the new configuration to both 
nodes, you will want to restart the cluster service on both nodes or 
just reboot both nodes.

-John