did you ever get this solved, I have a similar issue after I had a motherboard issue and had to replace and rebuild the server
(07/29/2013 11:58:44:348 PM) OVMAPI_4010E Attempt to send command: dispatch to server: SAAS-OVM-1.medecision.com failed. OVMAPI_4004E Server Failed Command: dispatch https://?uname?:?pwd?@g3nt configure_server_for_cluster lun /dev/mapper/36005076303ffd0070000000000000088 0004fb0000050000dd7fa086d586e3b4 , Status: org.apache.xmlrpc.XmlRpcException: exceptions.Exception:Already in cluster: c7c16373ed9a5721 [Mon Jul 29 23:58:44 EDT 2013] [Mon Jul 29 23:58:44 EDT 2013]
This will do the trick:
1- ensure that the server to be added to the pool is clean, i.e. re -fr /etc/ocfs2/cluster.conf, service ovs-agent stop, rm -fr /etc/ovs-agent/db/*, service over-agent start
2- copy the o2cb file from an existing pool member to the server to be added to the pool
3- rediscover the server, and boom, all good.....