tencent cloud

Overview

If you need to create a snapshot of the PVC data disk to back up 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.

Prerequisites

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

Directions

Backing up PVC

Creating VolumeSnapshotClass

1. Use the following YAML to create a VolumeSnapshotClass object:

   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
   

Creating PVC snapshot VolumeSnapshot

1. This document takes new-snapshot-demo as an example to use the following YAML to create a VolumeSnapshot object.

   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.

   $ 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. Run the following command to obtain the snapshot ID of the Volumesnapshotcontent object. The field is status.snapshotHandle (here takes snap-e406fc9m as an example). You can log in to the CVM console > Snapshot List and use the snapshot ID to check whether the snapshot exists, as shown below:

   $ 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. This document takes the VolumeSnapshot object new-snapshot-demo created in the previous step as an example and uses the following YAML to restore volume from the 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 (to schedule the Pod before creating the PV), that is, to specify volumeBindingMode: WaitForFirstConsumer, you need to deploy the Pod (mount the PVC) to trigger the PV creation (create a CBS from the snapshot and bind it to the PV).