Let's perform the following steps to deploy a Ceph cluster using the Rook Operator:

1. Create a Ceph cluster:

$ cat <<EOF | kubectl apply -f -
apiVersion: ceph.rook.io/v1
kind: CephCluster
metadata:
  name: rook-ceph
  namespace: rook-ceph
spec:
  cephVersion:
    image: ceph/ceph:v14.2.3-20190904
  dataDirHostPath: /var/lib/rook
  mon:
    count: 3
  dashboard:
    enabled: true
  storage:
    useAllNodes: true
    useAllDevices: false
    directories:
    - path: /var/lib/rook
EOF

2. Verify that all pods are running:

$ kubectl get pod -n rook-ceph

Within a minute, a fully functional Ceph cluster will be deployed and ready to be used. You can read more about Ceph in the Rook Ceph Storage Documentation link in the See also section.