[ClusterLabs] Two node cluster without fencing and no split brain?

[john tillman]

Greetings,

Is it possible to configure a two node cluster (pacemaker 2.0) without
fencing and avoid split brain?

I was hoping there was a way to use a 3rd node's ip address, like from a
network switch, as a tie breaker to provide quorum.  A simple successful
ping would do it.

I realize that this 'ping' approach is not the bullet proof solution that
fencing would provide.  However, it may be an improvement over two nodes
alone.

Is there a configuration like that already?  Any other ideas?

Pointers to useful documents/discussions on avoiding split brain with two
node clusters would be welcome.

Best regards,
John