Openais - zombies and the revenge of the undead

Are you trying to start your cluster and all you get out of it is a set of duplicate and defunct processes, similar to the following?

4129 ?        Ssl    0:01 /usr/sbin/corosync
4134 ?        S      0:00  \_ /usr/lib64/heartbeat/stonithd
4135 ?        S      0:00  \_ /usr/lib64/heartbeat/cib
4136 ?        Z      0:00  \_ [lrmd] <defunct>
4137 ?        S      0:00  \_ /usr/lib64/heartbeat/attrd
4138 ?        Z      0:00  \_ [pengine] <defunct>
4139 ?        Z      0:00  \_ [crmd] <defunct>
4141 ?        S      0:00  \_ /usr/lib64/heartbeat/stonithd
4142 ?        S      0:00  \_ /usr/lib64/heartbeat/cib
4143 ?        S      0:00  \_ /usr/lib64/heartbeat/lrmd
4144 ?        S      0:00  \_ /usr/lib64/heartbeat/attrd
4145 ?        S      0:00  \_ /usr/lib64/heartbeat/pengine
4652 ?        S      0:00  \_ /usr/lib64/heartbeat/crmd


Check /etc/corosync/service.d/
If in there you see a pcmk file *and* Pacemaker is specified as service in your /etc/corosync/corosync.conf  you have your answer.
Just leave your .config file as is and get rid of the pcmk file instead.
Reboot your node, and you' re ready to go.