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Creating Snapshot and Using It to Restore Volume

Last updated: 2023-09-26 15:14:14

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Scenario

If you need to create a snapshot of the PVC data disk to backup data, or to restore the backup snapshot data to a new PVC, you can use the CBS-CSI add-on. This document describes how to use the CBS-CSI add-on to implement data backup and restoration of PVC.

Preparations

You have created a TKE cluster of v1.18 or later versions. For more information, see Creating a Cluster.
You have installed the latest version of CBS-CSI add-on. For more information, see CBS CSI Documents.

Instructions

Backing up PVC

Creating a VolumeSnapshotClass

1. Use the following YAML to create a VolumeSnapshotClass object, as shown below:
apiVersion: snapshot.storage.k8s.io/v1beta1
kind: VolumeSnapshotClass
metadata: 
  name: cbs-snapclass
driver: com.tencent.cloud.csi.cbs
deletionPolicy: Delete
2. Run the following command to see if the VolumeSnapshotClass is created successfully:
$ kubectl get volumesnapshotclass
NAME            DRIVER                      DELETIONPOLICY   AGE
cbs-snapclass   com.tencent.cloud.csi.cbs   Delete           17m

Create a PVC snapshot object VolumeSnapshot

1. In this example, we use the snapshot name new-snapshot-demo to create a VolumeSnapshot object using the following YAML. The example is as follows:
apiVersion: snapshot.storage.k8s.io/v1beta1
kind: VolumeSnapshot
metadata:
  name: new-snapshot-demo
spec:
  volumeSnapshotClassName: cbs-snapclass
  source:
  persistentVolumeClaimName: csi-pvc
2. Run the following command to check whether the Volumesnapshot and Volumesnapshotcontent objects have been created successfully. If READYTOUSE is true, the creation is successful, as shown below:
$ kubectl get volumesnapshot
NAME                READYTOUSE   SOURCEPVC            SOURCESNAPSHOTCONTENT   RESTORESIZE   SNAPSHOTCLASS   SNAPSHOTCONTENT                                    CREATIONTIME   AGE
new-snapshot-demo   true         www1-ivantestweb-0                           10Gi          cbs-snapclass   snapcontent-ea11a797-d438-4410-ae21-41d9147fe610   22m            22m
$ kubectl get volumesnapshotcontent
NAME                                               READYTOUSE   RESTORESIZE   DELETIONPOLICY   DRIVER                      VOLUMESNAPSHOTCLASS   VOLUMESNAPSHOT      AGE
snapcontent-ea11a797-d438-4410-ae21-41d9147fe610   true         10737418240   Delete           com.tencent.cloud.csi.cbs   cbs-snapclass         new-snapshot-demo   22m
3. Execute the following command to obtain the snapshot ID of the VolumeSnapshotContent object. The field is status.snapshotHandle (e.g., snap-e406fc9m). You can confirm whether the snapshot exists in the Cloud Service Console > Snapshot List based on the snapshot ID. Example:
$ kubectl get volumesnapshotcontent snapcontent-ea11a797-d438-4410-ae21-41d9147fe610 -oyaml
apiVersion: snapshot.storage.k8s.io/v1beta1
kind: VolumeSnapshotContent
metadata:
  creationTimestamp: "2020-11-04T08:58:39Z"
  finalizers:
  - snapshot.storage.kubernetes.io/volumesnapshotcontent-bound-protection
  name: snapcontent-ea11a797-d438-4410-ae21-41d9147fe610
  resourceVersion: "471437790"
  selfLink: /apis/snapshot.storage.k8s.io/v1beta1/volumesnapshotcontents/snapcontent-ea11a797-d438-4410-ae21-41d9147fe610
  uid: 70d0390b-79b8-4276-aa79-a32e3bdef3d6
spec:
  deletionPolicy: Delete
  driver: com.tencent.cloud.csi.cbs
  source:
    volumeHandle: disk-7z32tin5
  volumeSnapshotClassName: cbs-snapclass
  volumeSnapshotRef:
    apiVersion: snapshot.storage.k8s.io/v1beta1
    kind: VolumeSnapshot
    name: new-snapshot-demo
    namespace: default
    resourceVersion: "471418661"
    uid: ea11a797-d438-4410-ae21-41d9147fe610
status:
  creationTime: 1604480319000000000
  readyToUse: true
  restoreSize: 10737418240
  snapshotHandle: snap-e406fc9m

Restoring data from the snapshot to a new PVC

1. In this document, we use the VolumeSnapshot object named new-snapshot-demo created in the steps above as an example. The following YAML demonstrates how to restore a volume from a snapshot:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: restore-test
spec:
  storageClassName: cbs-csi
  dataSource:
  name: new-snapshot-demo
  kind: VolumeSnapshot
  apiGroup: snapshot.storage.k8s.io
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
2. Run the following command to check whether the restored PVC has been created successfully. You can view the corresponding diskid in the PV (here takes disk-gahz1kw1 as an example).
$ kubectl get pvc restore-test
NAME           STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
restore-test   Bound    pvc-80b98084-29a3-4a38-a96c-2f284042cf4f   10Gi       RWO            cbs-csi        97s
$ kubectl get pv pvc-80b98084-29a3-4a38-a96c-2f284042cf4f -oyaml
apiVersion: v1
kind: PersistentVolume
metadata:
  annotations:
    pv.kubernetes.io/provisioned-by: com.tencent.cloud.csi.cbs
  creationTimestamp: "2020-11-04T12:08:25Z"
  finalizers:
  - kubernetes.io/pv-protection
  name: pvc-80b98084-29a3-4a38-a96c-2f284042cf4f
  resourceVersion: "474676883"
  selfLink: /api/v1/persistentvolumes/pvc-80b98084-29a3-4a38-a96c-2f284042cf4f
  uid: 5321df93-5f21-4895-bafc-71538d50293a
spec:
  accessModes:
  - ReadWriteOnce
  capacity:
    storage: 10Gi
  claimRef:
    apiVersion: v1
    kind: PersistentVolumeClaim
    name: restore-test
    namespace: default
    resourceVersion: "474675088"
    uid: 80b98084-29a3-4a38-a96c-2f284042cf4f
  csi:
    driver: com.tencent.cloud.csi.cbs
    fsType: ext4
    volumeAttributes:
      diskType: CLOUD_PREMIUM
      storage.kubernetes.io/csiProvisionerIdentity: 1604478835151-8081-com.tencent.cloud.csi.cbs
    volumeHandle: disk-gahz1kw1
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: topology.com.tencent.cloud.csi.cbs/zone
          operator: In
          values:
          - ap-beijing-2
  persistentVolumeReclaimPolicy: Delete
  storageClassName: cbs-csi
  volumeMode: Filesystem
status:
  phase: Bound
Note
If StorageClass uses topology awareness (schedule the Pod first and then create the PV), that is, to specify volumeBindingMode: WaitForFirstConsumer, you need to deploy the Pod (to mount the PVC) to trigger the creation of the PV (create a new CBS from the snapshot and bind it to the PV).

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