tencent cloud

Operation Scenarios

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.

Prerequisites

• You have created a TKE cluster or created a Kubernetes cluster in Tencent Cloud CVM. The cluster version is v1.18 or later.
• You have installed CBS-CSI add-on.
• You have granted related permissions of CBS snapshot for TKE_QCSRole on the Access Management page of the console. For details, see CBS-CSI.

Operation Directions

Restoring 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 check whether the VolumeSnapshotClass has been created successfully, as shown below:

   $ kubectl get volumesnapshotclass
   NAME            DRIVER                      DELETIONPOLICY   AGE
   cbs-snapclass   com.tencent.cloud.csi.cbs   Delete           17m
   

Create a PVC snapshot object VolumeSnapshot

1. This document takes new-snapshot-demo as the snapshot name to create a VolumeSnapshot. Use the following YAML to create a VolumeSnapshot object, as shown below:

   apiVersion: snapshot.storage.k8s.io/v1beta1
   kind: VolumeSnapshot
   metadata:
     name: new-snapshot-demo
   spec:
     volumeSnapshotClassName: cbs-snapclass # Use the VolumeSnapshotClass created in the above steps
     source:
       persistentVolumeClaimName: ssd-pvc # Replace it with the PVC name that needs to be backed up
   

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         ssd-pvc                             20Gi          cbs-snapclass   snapcontent-170b2161-f158-4c9e-a090-a38fdfd84a3e   2m36s          2m50s
   $ kubectl get volumesnapshotcontent
   NAME                                               READYTOUSE   RESTORESIZE   DELETIONPOLICY   DRIVER                      VOLUMESNAPSHOTCLASS   VOLUMESNAPSHOT      AGE
   snapcontent-170b2161-f158-4c9e-a090-a38fdfd84a3e   true         21474836480   Delete           com.tencent.cloud.csi.cbs   cbs-snapclass         new-snapshot-demo   3m3s
   

3. Run the following command to obtain the snapshot ID of the Volumesnapshotcontent object. The field is status.snapshotHandle (here takes snap-rsk8v75j as an example). You can log in to the TKE console .com/tke2) and use the snapshot ID to check whether the snapshot exists, as shown below:

   $ kubectl get volumesnapshotcontent -o yaml snapcontent-170b2161-f158-4c9e-a090-a38fdfd84a3e
   ...
   status:
   creationTime: 1607331318000000000
   readyToUse: true
   restoreSize: 21474836480
   snapshotHandle: snap-rsk8v75j
   

Restoring data from the snapshot to a new PVC

1. This document takes the VolumeSnapshot object new-snapshot-demo created in the above step as an example. Use the following YAML to restore data from the snapshot to a new PVC, as shown below:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: restore-test
   spec:
     storageClassName: ssd-csi # Customize the storage class as needed
     dataSource:
       name: new-snapshot-demo # Use the VolumeSnapshot created in the above step
       kind: VolumeSnapshot
       apiGroup: snapshot.storage.k8s.io
     accessModes:
       - ReadWriteOnce # CBS is block storage, which only supports single machine read and write
     resources:
       requests:
         storage: 50Gi # The recommended storage capacity is the same as the capacity of the restored PVC
   

2. Run the following command. You can check that the PVC has been created and bound to the PV, and you can find the corresponding diskid (here takes disk-ju0hw7no as an example) in the PV, as shown below:

   $ kubectl get pvc restore-test
   NAME           STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   restore-test   Bound    pvc-940edf09-d622-4126-992b-0a209f048c7d   60Gi       RWO            ssd-topology   6m8s
   $ kubectl get pv pvc-940edf09-d622-4126-992b-0a209f048c7d -o yaml
   ...
   spec:
   ...
   volumeHandle: disk-ju0hw7no
   ...
   

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).