Remove failed node

pvecm status
 
Highest expected: 4

pvecm delnode <hostname>
 
Killing node 2

pvecm status
 
Highest expected: 3

And reload WebUI to refresh cluster nodes.

ceph mon remove <host>

ceph osd out osd.2
ceph osd crush remove osd.2
ceph auth del osd.2
ceph osd rm osd.2
ceph osd crush rm <host>