pvecm
Proxmox VE Cluster Manager.
TLDR
Add the current node to an existing cluster
$ pvecm add [hostname_or_ip]
Add a node to the cluster configuration (internal use)
$ pvecm addnode [node]
Display the version of the cluster join API available on this node
$ pvecm apiver
Generate new cluster configuration
$ pvecm create [clustername]
Remove a node from the cluster configuration
$ pvecm delnode [node]
Display the local view of the cluster nodes
$ pvecm nodes
Display the local view of the cluster status
$ pvecm status