cluster Pacemaker is a cluster resource manager. It achieves maximum availability for your cluster services (aka. resources) by detecting and recovering from node and resource-level failures by making use of the messaging and membership capabilities provided by your preferred cluster infrastructure (either OpenAIS or Heartbeat). Enable sys-cluster/openais support. Enable sys-cluster/cman support. Enable sys-cluster/heartbeat support. Enable SMTP support via net-libs/libsmtp