Once Corosync and Pacemaker are installed, we only need to modify a single configuration file to activate them. As we mentioned earlier and showed in the introduction diagram, Corosync is the conduit that Pacemaker uses for communication. Corosync also binds itself to services that rely on its channels, so it will also launch Pacemaker on our behalf.
This recipe will explain how to create a simple configuration for Corosync that will establish a secure Pacemaker cluster.