Back up and restore persistent storage for your GKE clusters

This page shows you how to back up and restore the underlying Filestore storage associated with your GKE clusters using Kubernetes volume snapshots.

Creating a Kubernetes volume snapshot is equivalent to creating a Filestore backup.

For more information, see About Kubernetes volume snapshots.

Requirements

To use volume snapshots on GKE, you must meet the following requirements:

• You must deploy the Filestore CSI driver. Only the following Filestore service tiers are supported:

  • Basic HDD with GKE version 1.21 or later
  • Basic SSD with GKE version 1.21 or later
  • Zonal (10 TiB to 100 TiB) with GKE version 1.27 or later
  • Enterprise with GKE version 1.25 or later

• Use control plane versions 1.17 or later. To use the Filestore CSI driver in a VolumeSnapshot, use the GKE version number applicable to your service tier.

• Have an existing PersistentVolumeClaim to use for a snapshot. The PersistentVolume you use for a snapshot source must be managed by a CSI driver. You can verify that you're using a CSI driver by checking that the PersistentVolume spec has a csi section with driver: pd.csi.storage.gke.io or filestore.csi.storage.gke.io. If the PersistentVolume is dynamically provisioned by the CSI driver as described in the following sections, it's managed by the CSI driver.

Limitations

• Snapshot volumes have the same size restrictions as regular volumes. For example, Filestore snapshots must be greater than or equal to 1 TiB in size for the basic HDD tier.

• The Filestore CSI driver does not support dynamic provisioning or backup workflows for the following Filestore service tiers:

  • Zonal (1 TiB to 9.75 TiB)
  • Regional

• You can only back up one share per instance at a time. With regard to storage pools, backup requests issued from two different shares from two different Filestore instances will execute simultaneously.

• Singleshare backups can only be restored to singleshare volumes. Using the Filestore CSI driver, you can only restore a singleshare volume to a new Filestore instance.

  • The new instance must use the same service tier as the backup.
  • The new instance must match the same minimum capacity as the backup.

• Filestore backup restore operations to the source or to an existing Filestore instance are not supported. For a complete list of feature limitations, see Filestore backup feature limitations.

• Multishare backups are not supported.

Before you begin

Before you start, make sure you have performed the following tasks:

• Enable the Google Kubernetes Engine API.
Enable Google Kubernetes Engine API
• If you want to use the Google Cloud CLI for this task, install and then initialize the gcloud CLI. If you previously installed the gcloud CLI, get the latest version by running gcloud components update.
  Note: For existing gcloud CLI installations, make sure to set the compute/region and compute/zone properties. By setting default locations, you can avoid errors in gcloud CLI like the following: One of [--zone, --region] must be supplied: Please specify location.

Creating and using a volume snapshot

The examples in this document show you how to do the following tasks:

1. Create a PersistentVolumeClaim and Deployment.
2. Add a file to the PersistentVolume that the Deployment uses.
3. Create a VolumeSnapshotClass to configure the snapshot.
4. Create a volume snapshot of the PersistentVolume.
5. Delete the test file.
6. Restore the PersistentVolume to the snapshot you created.
7. Verify that the restoration worked.

To use a volume snapshot, you must complete the following steps:

1. Create a VolumeSnapshotClass object to specify the CSI driver and deletion policy for your snapshot.
2. Create a VolumeSnapshot object to request a snapshot of an existing PersistentVolumeClaim.
3. Reference the VolumeSnapshot in a PersistentVolumeClaim to restore a volume to that snapshot or create a new volume using the snapshot.

Create a PersistentVolumeClaim and a Deployment

1. To create the PersistentVolumeClaim object, save the following manifest as my-pvc.yaml:

   Filestore

    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: my-pvc
    spec:
      storageClassName: enterprise-rwx
      accessModes:
      - ReadWriteMany
      resources:
        requests:
          storage: 1Ti
   

   This example creates an enterprise tier Filestore PVC. To learn more, see Access Filestore instances with the Filestore CSI driver.

   For spec.storageClassName, you can specify any storage class that uses a supported CSI driver.

2. Apply the manifest:

   kubectl apply -f my-pvc.yaml
   

3. To create a Deployment, save the following manifest as my-deployment.yaml:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: hello-app
   spec:
     selector:
       matchLabels:
         app: hello-app
     template:
       metadata:
         labels:
           app: hello-app
       spec:
         containers:
         - name: hello-app
           image: google/cloud-sdk:slim
           args: [ "sleep", "3600" ]
           volumeMounts:
           - name: sdk-volume
             mountPath: /usr/share/hello/
         volumes:
         - name: sdk-volume
           persistentVolumeClaim:
             claimName: my-pvc
   

4. Apply the manifest:

   kubectl apply -f my-deployment.yaml
   

5. Check the status of the Deployment:

   kubectl get deployment hello-app
   

   It might take some time for the Deployment to become ready. You can run the preceding command until you see an output similar to the following:

   NAME        READY   UP-TO-DATE   AVAILABLE   AGE
   hello-app   1/1     1            1           2m55s
   

Add a test file to the volume

1. List the Pods in the Deployment:

   kubectl get pods -l app=hello-app
   

   The output is similar to the following:

   NAME                         READY   STATUS    RESTARTS   AGE
   hello-app-6d7b457c7d-vl4jr   1/1     Running   0          2m56s
   

2. Create a test file in a Pod:

   kubectl exec POD_NAME \
       -- sh -c 'echo "Hello World!" > /usr/share/hello/hello.txt'
   

   Replace POD_NAME with the name of the Pod.

3. Verify that the file exists:

   kubectl exec POD_NAME \
       -- sh -c 'cat /usr/share/hello/hello.txt'
   

   The output is similar to the following:

   Hello World!
   

Create a VolumeSnapshotClass object

Create a VolumeSnapshotClass object to specify the CSI driver and deletionPolicy for your volume snapshot. You can reference VolumeSnapshotClass objects when you create VolumeSnapshot objects.

1. Save the following manifest as volumesnapshotclass.yaml.

   Filestore

   apiVersion: snapshot.storage.k8s.io/v1
   kind: VolumeSnapshotClass
   metadata:
     name: my-snapshotclass
   driver: filestore.csi.storage.gke.io
   parameters:
     type: backup
   deletionPolicy: Delete
   

   In this example:

   • The driver field is used by the CSI driver to provision the snapshot. In this example, filestore.csi.storage.gke.io uses the Filestore CSI driver.
   • ThedeletionPolicy field tells GKE what to do with the VolumeSnapshotContent object and the underlying snapshot when the bound VolumeSnapshot object is deleted. Specify Delete to delete the VolumeSnapshotContent object and the underlying snapshot. Specify Retain if you want to keep the VolumeSnapshotContent and the underlying snapshot.

2. Apply the manifest:

   kubectl apply -f volumesnapshotclass.yaml
   

Create a VolumeSnapshot

A VolumeSnapshot object is a request for a snapshot of an existing PersistentVolumeClaim object. When you create a VolumeSnapshot object, GKE automatically creates and binds it with a VolumeSnapshotContent object, which is a resource in your cluster like a PersistentVolume object.

1. Save the following manifest as volumesnapshot.yaml.

   apiVersion: snapshot.storage.k8s.io/v1
   kind: VolumeSnapshot
   metadata:
     name: my-snapshot
   spec:
     volumeSnapshotClassName: my-snapshotclass
     source:
       persistentVolumeClaimName: my-pvc
   

2. Apply the manifest:

   kubectl apply -f volumesnapshot.yaml
   

   After you create a Volume snapshot, GKE creates a corresponding VolumeSnapshotContent object in the cluster. This object stores the snapshot and bindings of VolumeSnapshot objects. You don't interact with VolumeSnapshotContents objects directly.

3. Confirm that GKE created the VolumeSnapshotContents object:

   kubectl get volumesnapshotcontents
   

   The output is similar to the following:

   NAME                                               AGE
   snapcontent-cee5fb1f-5427-11ea-a53c-42010a1000da   55s
   

After the Volume snapshot content is created, the CSI driver you specified in the VolumeSnapshotClass creates a snapshot on the corresponding storage system. After GKE creates a snapshot on the storage system and binds it to a VolumeSnapshot object on the cluster, the snapshot is ready to use. You can check the status by running the following command:

kubectl get volumesnapshot \
  -o custom-columns='NAME:.metadata.name,READY:.status.readyToUse'

If the snapshot is ready to use, the output is similar to the following:

NAME               READY
my-snapshot        true

Delete the test file

1. Delete the test file that you created:

   kubectl exec POD_NAME \
       -- sh -c 'rm /usr/share/hello/hello.txt'
   

2. Verify that the file no longer exists:

   kubectl exec POD_NAME \
       -- sh -c 'cat /usr/share/hello/hello.txt'
   

   The output is similar to the following:

   cat: /usr/share/hello/hello.txt: No such file or directory
   

Restore the volume snapshot

1. Save the following manifest as pvc-restore.yaml:

   Filestore

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: pvc-restore
   spec:
     dataSource:
       name: my-snapshot
       kind: VolumeSnapshot
       apiGroup: snapshot.storage.k8s.io
     storageClassName: enterprise-rwx
     accessModes:
     - ReadWriteMany
     resources:
       requests:
         storage: 1Ti
   

   Note: The namespace of the PersistentVolumeClaim must be the same as the namespace of the VolumeSnapshot.

2. Apply the manifest:

   kubectl apply -f pvc-restore.yaml
   

3. Update the my-deployment.yaml file to use the new PersistentVolumeClaim:

   ...
   volumes:
   - name: my-volume
     persistentVolumeClaim:
       claimName: pvc-restore
   

4. Apply the updated manifest:

   kubectl apply -f my-deployment.yaml
   

Check that the snapshot restored successfully

1. Get the name of the new Pod that GKE creates for the updated Deployment:

    kubectl get pods -l app=hello-app
   

Verify that the test file exists:

   kubectl exec NEW_POD_NAME \
       -- sh -c 'cat /usr/share/hello/hello.txt'

Replace NEW_POD_NAME with the name of the new Pod that GKE created.

The output is similar to the following:

   Hello World!

Import a pre-existing snapshot

You can use an existing volume snapshot created outside the current cluster to manually provision the VolumeSnapshotContents object. For example, you can populate a volume in GKE with a snapshot of another Google Cloud resource created in a different cluster.

1. Locate the name of your snapshot.

   Google Cloud console

   Go to https://console.cloud.google.com/compute/snapshots.

   Google Cloud CLI

   Run the following command:

   gcloud compute snapshots list
   

   The output is similar to the following:

   NAME                                           DISK_SIZE_GB  SRC_DISK                                                     STATUS
   snapshot-5e6af474-cbcc-49ed-b53f-32262959a0a0  1             us-central1-b/disks/pvc-69f80fca-bb06-4519-9e7d-b26f45c1f4aa READY
   

2. Save the following VolumeSnapshot manifest as restored-snapshot.yaml.

   apiVersion: snapshot.storage.k8s.io/v1
   kind: VolumeSnapshot
   metadata:
     name: restored-snapshot
   spec:
     volumeSnapshotClassName: my-snapshotclass
     source:
       volumeSnapshotContentName: restored-snapshot-content
   

3. Apply the manifest:

   kubectl apply -f restored-snapshot.yaml
   

4. Save the following VolumeSnapshotContent manifest as restored-snapshot-content.yaml. Replace the snapshotHandle field with your project ID and snapshot name. Both volumeSnapshotRef.name and volumeSnapshotRef.namespace must point to the previously created VolumeSnapshot for the bi-directional binding to be valid.

   apiVersion: snapshot.storage.k8s.io/v1
   kind: VolumeSnapshotContent
   metadata:
     name: restored-snapshot-content
   spec:
     deletionPolicy: Retain
     driver: filestore.csi.storage.gke.io
     source:
       snapshotHandle: projects/PROJECT_ID/global/snapshots/SNAPSHOT_NAME
     volumeSnapshotRef:
       kind: VolumeSnapshot
       name: restored-snapshot
       namespace: default
   

5. Apply the manifest:

   kubectl apply -f restored-snapshot-content.yaml
   

6. Save the following PersistentVolumeClaim manifest as restored-pvc.yaml. The Kubernetes storage controller will find a VolumeSnapshot named restored-snapshot and then try to find, or dynamically create, a PersistentVolume as the data source. You can then utilize this PVC in a Pod to access the restored data.

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: restored-pvc
   spec:
     dataSource:
       name: restored-snapshot
       kind: VolumeSnapshot
       apiGroup: snapshot.storage.k8s.io
     storageClassName: enterprise-rwx
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 1Gi
   

7. Apply the manifest:

   kubectl apply -f restored-pvc.yaml
   

8. Save the following Pod manifest as restored-pod.yaml referring to the PersistentVolumeClaim. The CSI driver will provision a PersistentVolume and populate it from the snapshot.

   apiVersion: v1
   kind: Pod
   metadata:
     name: restored-pod
   spec:
     containers:
     - name: busybox
       image: busybox
       args:
       - sleep
       - "3600"
       volumeMounts:
       - name: source-data
         mountPath: /demo/data
     volumes:
     - name: source-data
       persistentVolumeClaim:
         claimName: restored-pvc
         readOnly: false
   

9. Apply the manifest:

   kubectl apply -f restored-pod.yaml
   

10. Verify that the file has been restored:

    kubectl exec restored-pod -- sh -c 'cat /demo/data/hello.txt'
    

Clean up

To avoid incurring charges to your Google Cloud account for the resources used on this page, follow these steps.

1. Delete the VolumeSnapshot:

   kubectl delete volumesnapshot my-snapshot
   

   Note: If a volume snapshot's VolumeSnapshotClass has deletionPolicy:Delete, the corresponding VolumeSnapshotContent and the physical snapshot on the storage system are also deleted. If it has a deletionPolicy:Retain, GKE retains the underlying snapshot.

2. Delete the VolumeSnapshotClass:

   kubectl delete volumesnapshotclass my-snapshotclass
   

3. Delete the Deployment:

   kubectl delete deployments hello-app
   

4. Delete the PersistentVolumeClaim objects:

   kubectl delete pvc my-pvc pvc-restore
   

What's next

• Read the Kubernetes Volume Snapshot documentation.
• Learn about volume expansion.
• Learn how to manually install a CSI driver.
• Learn about Filestore as a file storage option for GKE.