A node running the full high-availability stack of corosync and all Pacemaker components. Cluster nodes may run cluster resources, run all Pacemaker command-line tools (crm_mon, crm_resource and so on), execute fencing actions, count toward cluster quorum, and serve as the cluster’s Designated Controller (DC).
pacemaker_remote
A small service daemon that allows a host to be used as a Pacemaker node without running the full cluster stack. Nodes running pacemaker_remote may run cluster resources and most command-line tools, but cannot perform other functions of full cluster nodes such as fencing execution, quorum voting or DC eligibility. The pacemaker_remote daemon is an enhanced version of Pacemaker’s local resource management daemon (LRMD).
remote node
A physical host running pacemaker_remote. Remote nodes have a special resource that manages communication with the cluster. This is sometimes referred to as the baremetal case.
guest node
A virtual host running pacemaker_remote. Guest nodes differ from remote nodes mainly in that the guest node is itself a resource that the cluster manages.
Note
Remote in this document refers to the node not being a part of the underlying corosync cluster. It has nothing to do with physical proximity. Remote nodes and guest nodes are subject to the same latency requirements as cluster nodes, which means they are typically in the same data center.
Note
It is important to distinguish the various roles a virtual machine can serve in Pacemaker clusters:
A virtual machine can run the full cluster stack, in which case it is a cluster node and is not itself managed by the cluster.
A virtual machine can be managed by the cluster as a resource, without the cluster having any awareness of the services running inside the virtual machine. The virtual machine is opaque to the cluster.
A virtual machine can be a cluster resource, and run pacemaker_remote to make it a guest node, allowing the cluster to manage services inside it. The virtual machine is transparent to the cluster.
