[Linux-cluster] 2-node fencing question
danwest at comcast.net
danwest at comcast.net
Mon Jul 31 13:20:07 UTC 2006
I was wondering if someone could shed some light on the following scenario:
We have a simple 2 node cluster defined with <cman expected_votes="1" two_node="1"/>. The fencing method is via
<clusternode name="node1" votes="1">
<fence>
<method name="single">
<device name="ipmilan" ipaddr="10.1.1.10"/>
</method>
</fence>
</clusternode>
<clusternode name="node2" votes="1">
<fence>
<method name="single">
<device name="ipmilan" ipaddr="10.1.1.20"/>
</method>
</fence>
</clusternode>
<fencedevice name="ipmilan" agent="fence_ipmilan" login="XXXX" passwd=XXXX"/>
The out-of-band IPMI is basically a crossover cable to each others IPMI interface.
A simple test of pulling the public interface one the node with an active resource results in each node being fenced. My understanding is that in the 2-node configuration the fencing is a race to see who can fence each other first. My concerns are the following:
1) If it is indeed a race it seems like both nodes successfully issue a /sbin/fence_ipmilan (ipmi_tool) resulting in both nodes being fenced.
2) Is there a way for this algorithm to determine which of the nodes was the one that had the problem? A simple race to fence could result in the faulty server winning.
Also is there a way to configure fence_ipmilan in cluster.xml to reboot rather than stop the server? fence_ipmilan by itself takes the o option (on,off,reboot)
Thanks,
Dan
More information about the Linux-cluster
mailing list