Configuring Corosync

Once Corosync and Pacemaker are installed, we only need to modify a single configuration file to activate them. As we've mentioned earlier and shown 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.

Getting ready

We have already installed everything we need, but if we are running an older Debian-based system such as Ubuntu or Mint, we have one more step. Before Corosync will work properly, we need to enable its startup script. Open the /etc/default/corosync file and make sure it contains this line:

START=yes 

Without it, Corosync won't run even if we start it manually. We removed it from system boot time, but that doesn't mean we never want it to run at all!

How to do it...

For this recipe, we...