复用 Released 状态的 pv - Powered by MinDoc

PV 回收策略
保留（Retain）
删除（Delete）

PV 回收策略

当用户不再使用其存储卷时，他们可以从 API 中将 PVC 对象删除，从而允许该资源被回收再利用。PersistentVolume 对象的回收策略告诉集群，当其被从申领中释放时如何处理该数据卷。目前，数据卷可以被 Retained（保留）、Recycled（回收，Recycle 已被废弃）或 Deleted（删除）。

保留（Retain）

回收策略 Retain 使得用户可以手动回收资源。当 PersistentVolumeClaim 对象被删除时，PersistentVolume 卷仍然存在，对应的数据卷被视为”已释放（released）”。由于卷上仍然存在这前一申领人的数据，该卷还不能用于其他申领。管理员可以通过下面的步骤来手动回收该卷：

删除 PersistentVolume 对象。与之相关的、位于外部基础设施中的存储资产（例如 AWS EBS、GCE PD、Azure Disk 或 Cinder 卷）在 PV 删除之后仍然存在。
根据情况，手动清除所关联的存储资产上的数据。
手动删除所关联的存储资产；如果你希望重用该存储资产，可以基于存储资产的定义创建新的 PersistentVolume 卷对象。

删除（Delete）

对于支持 Delete 回收策略的卷插件，删除动作会将 PersistentVolume 对象从 Kubernetes 中移除，同时也会从外部基础设施（如 AWS EBS、GCE PD、Azure Disk 或 Cinder 卷）中移除所关联的存储资产。动态供应的卷会继承其 StorageClass 中设置的回收策略，该策略默认为 Delete。管理员需要根据用户的期望来配置 StorageClass；否则 PV 卷被创建之后必须要被编辑或者修补。参阅更改 PV 卷的回收策略.

参考：https://kubernetes.io/zh/docs/concepts/storage/persistent-volumes/#reclaiming

[root@k8s-offline-master01 yaml]# kubectl  get pvc -n zcbus01
NAME           STATUS   VOLUME                           CAPACITY   ACCESS MODES   STORAGECLASS   AGE
datadir-zk-0   Bound    data-kafka-zookeeper-zcbus01-1   5Gi        RWO            zk-storage     65s
datadir-zk-1   Bound    data-kafka-zookeeper-zcbus01-0   5Gi        RWO            zk-storage     49s
datadir-zk-2   Bound    data-kafka-zookeeper-zcbus01-2   5Gi        RWO            zk-storage     30s
[root@k8s-offline-master01 yaml]# 
[root@k8s-offline-master01 yaml]# kubectl  get pv -n zcbus01
NAME                             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                  STORAGECLASS   REASON   AGE
data-kafka-zookeeper-zcbus01-0   5Gi        RWO            Retain           Bound    zcbus01/datadir-zk-1   zk-storage              68s
data-kafka-zookeeper-zcbus01-1   5Gi        RWO            Retain           Bound    zcbus01/datadir-zk-0   zk-storage              68s
data-kafka-zookeeper-zcbus01-2   5Gi        RWO            Retain           Bound    zcbus01/datadir-zk-2   zk-storage              68s

通过命令查看 pv 和 pvc yaml 配置
pv

[root@k8s-offline-master01 yaml]# kubectl  get pv data-kafka-zookeeper-zcbus01-0 -oyaml
apiVersion: v1
kind: PersistentVolume
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","kind":"PersistentVolume","metadata":{"annotations":{},"name":"data-kafka-zookeeper-zcbus01-0"},"spec":{"accessModes":["ReadWriteOnce"],"capacity":{"storage":"5Gi"},"local":{"path":"/data/zcbus01/zk/zkdata-01"},"nodeAffinity":{"required":{"nodeSelectorTerms":[{"matchExpressions":[{"key":"kubernetes.io/hostname","operator":"In","values":["192.168.0.105"]}]}]}},"persistentVolumeReclaimPolicy":"Retain","storageClassName":"zk-storage","volumeMode":"Filesystem"}}
    pv.kubernetes.io/bound-by-controller: "yes"
  creationTimestamp: "2021-10-31T23:10:22Z"
  finalizers:
  - kubernetes.io/pv-protection
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:status:
        f:phase: {}
    manager: kube-controller-manager
    operation: Update
    time: "2021-10-31T23:10:22Z"
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:kubectl.kubernetes.io/last-applied-configuration: {}
      f:spec:
        f:accessModes: {}
        f:capacity:
          .: {}
          f:storage: {}
        f:local:
          .: {}
          f:path: {}
        f:nodeAffinity:
          .: {}
          f:required:
            .: {}
            f:nodeSelectorTerms: {}
        f:persistentVolumeReclaimPolicy: {}
        f:storageClassName: {}
        f:volumeMode: {}
    manager: kubectl
    operation: Update
    time: "2021-10-31T23:10:22Z"
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          f:pv.kubernetes.io/bound-by-controller: {}
      f:spec:
        f:claimRef:
          .: {}
          f:apiVersion: {}
          f:kind: {}
          f:name: {}
          f:namespace: {}
          f:resourceVersion: {}
          f:uid: {}
    manager: kube-scheduler
    operation: Update
    time: "2021-10-31T23:10:38Z"
  name: data-kafka-zookeeper-zcbus01-0
  resourceVersion: "2391597"
  selfLink: /api/v1/persistentvolumes/data-kafka-zookeeper-zcbus01-0
  uid: ae6d652c-5315-4ff4-8d5b-fd3d69824319
spec:
  accessModes:
  - ReadWriteOnce
  capacity:
    storage: 5Gi
  claimRef:
    apiVersion: v1
    kind: PersistentVolumeClaim
    name: datadir-zk-1
    namespace: zcbus01
    resourceVersion: "2391590"
    uid: 4427dfec-e1b1-41e0-9904-f3cbb183c80c
  local:
    path: /data/zcbus01/zk/zkdata-01
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - 192.168.0.105
  persistentVolumeReclaimPolicy: Retain
  storageClassName: zk-storage
  volumeMode: Filesystem
status:
  phase: Bound

测试删除 pvc

[root@k8s-offline-master01 yaml]# kubectl  get pvc -n zcbus01
NAME           STATUS   VOLUME                           CAPACITY   ACCESS MODES   STORAGECLASS   AGE
datadir-zk-0   Bound    data-kafka-zookeeper-zcbus01-1   5Gi        RWO            zk-storage     3m32s
datadir-zk-1   Bound    data-kafka-zookeeper-zcbus01-0   5Gi        RWO            zk-storage     3m16s
datadir-zk-2   Bound    data-kafka-zookeeper-zcbus01-2   5Gi        RWO            zk-storage     2m57s

[root@k8s-offline-master01 yaml]# kubectl  delete pvc datadir-zk-2  -n zcbus01
persistentvolumeclaim "datadir-zk-2" deleted
[root@k8s-offline-master01 yaml]# kubectl  delete pvc datadir-zk-0  -n zcbus01
persistentvolumeclaim "datadir-zk-0" deleted
[root@k8s-offline-master01 yaml]# kubectl  delete pvc datadir-zk-1  -n zcbus01
persistentvolumeclaim "datadir-zk-1" deleted
[root@k8s-offline-master01 yaml]# kubectl  get pvc -n zcbus01
No resources found in zcbus01 namespace.

[root@k8s-offline-master01 yaml]# kubectl  get pv -n zcbus01
NAME                             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS     CLAIM                  STORAGECLASS   REASON   AGE
data-kafka-zookeeper-zcbus01-0   5Gi        RWO            Retain           Released   zcbus01/datadir-zk-1   zk-storage              4m32s
data-kafka-zookeeper-zcbus01-1   5Gi        RWO            Retain           Released   zcbus01/datadir-zk-0   zk-storage              4m32s
data-kafka-zookeeper-zcbus01-2   5Gi        RWO            Retain           Released   zcbus01/datadir-zk-2   zk-storage              4m32s

因为 pv 的 persistentVolumeReclaimPolicy 属性为 Retain，在删除 pvc 后 pv，会自动保留，所以 pv 状态变为 Released。
为了 pv 可以重新被挂载，需要执行 kubectl edit pv data-kafka-zookeeper-zcbus01-1 命令，清理 spec.claimRef 中的内容，以使 pv 成为可用状态。

清理之后，查看PV状态如下：

[root@k8s-offline-master01 yaml]# kubectl  get pv -n zcbus01
NAME                             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                  STORAGECLASS   REASON   AGE
data-kafka-zookeeper-zcbus01-0   5Gi        RWO            Retain           Available                          zk-storage              6m32s
data-kafka-zookeeper-zcbus01-1   5Gi        RWO            Retain           Released    zcbus01/datadir-zk-0   zk-storage              6m32s
data-kafka-zookeeper-zcbus01-2   5Gi        RWO            Retain           Released    zcbus01/datadir-zk-2   zk-storage              6m32s
[root@k8s-offline-master01 yaml]# kubectl edit pv  data-kafka-zookeeper-zcbus01-1
[root@k8s-offline-master01 yaml]# kubectl edit pv  data-kafka-zookeeper-zcbus01-2
[root@k8s-offline-master01 yaml]# kubectl  get pv -n zcbus01
NAME                             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
data-kafka-zookeeper-zcbus01-0   5Gi        RWO            Retain           Available           zk-storage              7m34s
data-kafka-zookeeper-zcbus01-1   5Gi        RWO            Retain           Available           zk-storage              7m34s
data-kafka-zookeeper-zcbus01-2   5Gi        RWO            Retain           Available           zk-storage              7m34s

此时PV可以被重复挂在使用了

文档更新时间: 2021-10-31 14:20 作者：阿力