Create volume snapshots

This page explains how to create a copy, or snapshot, of a storage volume at a specific point in time for your container application. A volume snapshot lets you bring a volume back to a prior state or provision a new volume.

This page is for developers within the application operator group, who are responsible for creating application workloads for their organization. For more information, see Audiences for GDC air-gapped documentation.

Before you begin

To run commands against a Kubernetes cluster, make sure you have the following resources:

  1. Locate the Kubernetes cluster name, or ask your Platform Administrator what the cluster name is.

  2. Sign in and generate the kubeconfig file for the Kubernetes cluster if you don't have one.

  3. Use the kubeconfig path of the Kubernetes cluster to replace KUBERNETES_CLUSTER_KUBECONFIG in these instructions.

To get the required permissions to manage volume snapshots, ask your Organization IAM Admin to grant you the Namespace Admin role (namespace-admin) in your project namespace.

Take a volume snapshot

To take a snapshot of a PersistentVolumeClaim object, create a VolumeSnapshot object. The system does not guarantee data consistency. Pause the application and flush data before taking a snapshot.

  1. Create a VolumeSnapshot custom resource:

    kubectl --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG \
    --namespace NAMESPACE apply -f - <<EOF
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: VOLUME_SNAPSHOT_NAME
spec:
  source:
    persistentVolumeClaimName: PVC_NAME
EOF

    Replace the following:

    • KUBERNETES_CLUSTER_KUBECONFIG: the kubeconfig file for the cluster.

    • NAMESPACE: the project namespace in which to create the volume snapshot.

    • VOLUME_SNAPSHOT_NAME: the VolumeSnapshot object name.

    • PVC_NAME: the name of the PVC for which you are creating a snapshot.

  2. The snapshot operation is complete when the .status.readyToUse field becomes true. You can use the following command to check the status:

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

  3. Update the PVC manifest with the volume snapshot specified as a data source:

    kubectl --kubeconfig KUBERNETES_CLUSTER_KUBECONFIG \
    --namespace NAMESPACE apply -f - <<EOF
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: PVC_NAME
spec:
  dataSource:
    name: VOLUME_SNAPSHOT_NAME
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  storageClassName: standard-rwo
  accessModes:
    - ReadWriteOnce
resources:
  requests:
    storage: 10Gi
EOF

    Replace the following:

    • KUBERNETES_CLUSTER_KUBECONFIG: the kubeconfig file for the cluster.

    • NAMESPACE: the namespace in which the PVC resource exists.

    • PVC_NAME: the name of the PVC for which you are creating a snapshot.

    • VOLUME_SNAPSHOT_NAME: the name of the volume snapshot.

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