以下是使用ceph RBD作為persistent volume的例子：

A PersistentVolume (PV) is a piece of networked storage in the cluster that has been provisioned by an administrator. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.

A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims can request specific size and access modes (e.g., can be mounted once read/write or many times read-only).

1. 先建立image在pool裡。

2. 建立 PV

[[email protected] kube]# cat pv_ceph.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: ceph-pv
spec:
  capacity:
    storage: 50Gi
  accessModes:
    - ReadWriteOnce
  rbd:
    monitors:
     - 10.0.200.11:6789
     - 10.0.200.13:6789
     - 10.0.200.14:6789
    pool: kube
    image: vol2
    user: kube
    secretRef:
      name: ceph-secret
    fsType: ext4
    readOnly: false
  persistentVolumeReclaimPolicy: Recycle

kubectl create -f pv_ceph.yaml

[[email protected] kube]# kubectl get pv
NAME                                       CAPACITY   ACCESSMODES   RECLAIMPOLICY   STATUS    CLAIM                   REASON    AGE
ceph-pv                                    50Gi       RWO           Recycle         Bound     default/ceph-claim                4d
pvc-ac668f99-3b8b-11e7-8af9-fa163e01317b   20Gi       RWO           Delete          Bound     default/ceph-claim-sc             4d

3.  建立pvc

[[email protected] kube]# cat pvc_ceph.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: ceph-claim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi

note: pvc和pv是一一對應的，所以storage在這設20G沒用

kubectl create -f pvc_ceph.yaml

[[email protected] kube]# kubectl get pvc
NAME            STATUS    VOLUME                                     CAPACITY   ACCESSMODES   AGE
ceph-claim      Bound     ceph-pv                                    50Gi       RWO           4d

4. 建立pod

[[email protected] kube]# cat frontend-pvc-controller.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: frontendpvc
  labels:
    name: frontendpvc
spec:
  replicas: 1
  selector:
    name: frontendpvc
  template:
    metadata:
      labels:
        name: frontendpvc
    spec:
      containers:
      - name: frontendpvc
        image: kubeguide/guestbook-php-frontend
        env:
        - name: GET_HOSTS_FROM
          value: env
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: /mnt/rbd
          name: ceph-vol
      volumes:
      - name: ceph-vol
        persistentVolumeClaim:
          claimName: ceph-claim