[Pacemaker] How to avoid dual fencing ?

[Kristoffer Grönlund]

On Mon, 24 Mar 2014 19:41:16 +0800
邓尧 <torshie at gmail.com> wrote:

> I'm configuring a 2-node cluster on CentOS 6 with corosync +
> pacemaker + cman. Everything works well except fencing.
> 
> I'm using IPMI as the fencing device, I know it's not the best fencing
> device, but this is the only option I have.
> Manual fencing a node (pcs stonith fence <node>) works well: peer
> node goes offline, resources migrate as expected. However, if network
> traffic between the two nodes is blocked by iptables, both nodes will
> try to fence each other, and both would success, which result in both
> nodes offline.
> 
> How to avoid such problem ?

You'll need to have one node take priority, by setting different
delays on the two nodes so that one of them will fence before the
other (see the "delay" parameter).

-- 
// Kristoffer Grönlund
// kgronlund at suse.com