Back up Filestore storage using volume snapshots


This page shows you how to back up and restore Filestore storage 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, which supports the following Filestore service tiers:

    • Basic HDD with GKE version 1.21 or later
    • Basic SSD with GKE version 1.21 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 GKE versions 1.21 or later.

  • 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 with higher capacity band (previously high scale ssd)
    • Zonal with lower capacity band
  • 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.

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

You can reference a VolumeSnapshot in a PersistentVolumeClaim to provision a new volume with data from an existing volume.

To reference a VolumeSnapshot in a PersistentVolumeClaim, add the dataSource field to your PersistentVolumeClaim.

In this example, you reference the VolumeSnapshot that you created in a new PersistentVolumeClaim and update the Deployment to use the new claim.

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

    Filestore

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

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
    
  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