On any host that is meant to be part of a Pacemaker cluster, you must first establish cluster communications through the Corosync messaging layer. This involves installing the following packages (and their dependencies, which your package manager will normally install automatically): pacemaker (Note that the crm shell should be downloaded separately.) crmsh corosync cluster-glue fence-agents (Fedora only; all other distributions use fencing agents from cluster-glue) resource-agents