Overview of VAST Snapshots and Clones
You can protect Kubernetes volumes using VAST Cluster snapshots.
A snapshot is a reference point that preserves the exact folder structure and data content of a data path at a point in time. Snapshots serve as a virtual copy of the data you had at previous points in time and enable you to restore files or directories after deletion or modification.
Note: For more information about VAST snapshots, see the VAST Cluster Administrator's Guide.
You can create snapshots for your Persistent Volume Claims (PVCs) to be able to restore the data based on an existing snapshot.
VAST Block CSI Driver lets you create an instantly writeable clone of a Kubernetes volume.
VAST Block CSI Driver also supports provisioning for read-only PVCs based on Kubernetes-created snapshots.
Create Block Volume Snapshot
To create a snapshot of a Kubernetes volume using a Kubernetes YAML configuration file:
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Create a YAML configuration file that adds a volume snapshot. In the file (see the example below for correct indentation and line breaks when specifying the keywords):
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In
medadata:nameis the Persistent Volume Claim (PVC) name to store the snapshot.
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In
spec:-
volumeSnaphotClassName: the name of the block volume snapshot class. -
In
source:persistentVolumeClaimNameis the PVC name for the block volume being protected.
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For example:
apiVersion: snapshot.storage.k8s.io/v1 kind: VolumeSnapshot metadata: name: snapshot-pvc-1 spec: volumeSnapshotClassName: vastdata-snapshot source: persistentVolumeClaimName: vast-pvc-1 -
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Apply the YAML configuration file:
kubectl apply -f vast-csi-deployment.yaml -
Verify that the PVC snapshot has been created with the following command:
kubectl get vsThe output is similar to the following:
NAME READYTOUSE SOURCEPVC SOURCESNAPSHOTCONTENT RESTORESIZE SNAPSHOTCLASS SNAPSHOTCONTENT CREATIONTIME AGE snapshot-pvc-1 true vast-pvc-1 0 vastdata-snapshot snapcontent-8b1627cc-d50a-4bdb-a1b4-67931d36eb85 50m 49m
Restore Block Volume from Snapshot
To restore a PVC from an existing snapshot, attach the snapshot to another PVC.
You can choose to provide read-only or read/write access to the restored block volume using accessModes options in the YAML configuration file.
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If attached in read-only mode (
ReadOnlyMany), the restored volume is mounted to the snapshot's source folder (<snapshot path>/.snapshot/<snapshot name>). It does not have a view or a quota on the VAST cluster, not can it be expanded through Kubernetes volume expansion. -
If attached in read/write mode (
ReadWriteMany), a view and a quota is created automatically for it on the VAST cluster, and the restored volume is mounted to the view's directory. The restored volume can be expanded like any other regular volume.
To restore a volume:
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Create a YAML configuration file to attach the snapshot to a PVC. In the file (see the example below for correct indentation and line breaks when specifying the keywords):
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In
metadata:nameis the Persistent Volume Claim (PVC) name for the volume that will contain the restored data.
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In
spec:-
In
accessModes, specify the access mode for the restored volume:-
ReadWriteManyfor read/write -
ReadOnlyManyfor read-only
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storageClassNameis the name of the storage class used for the PVC. -
In
dataSource:nameis the PVC name of the volume that stores the snapshot.
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For example:
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: pvc-restore spec: accessModes: - ReadWriteOnce resources: requests: storage: 10Gi storageClassName: vastdata-filesystem dataSource: name: snapshot-pvc-1 kind: VolumeSnapshot apiGroup: snapshot.storage.k8s.io -
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Deploy the YAML configuration file:
kubectl apply -f vast-csi-deployment.yamlThe output is similar to the following:
persistentvolumeclaim/pvc-restore created -
Verify that the restored PVC can be displayed:
kubectl get pvcThe output is similar to the following:
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE pvc-restore Bound pvc-c212dc9e-1b72-49da-8a58-8c1ceb97b9e3 1Gi RO vastdata-filesystem 7s
Clone Block Volume or Block Volume Snapshot
With VAST Block CSI Driver, you can create an instantly writable clone of either a block volume snapshot or another block volume.
When cloning a block volume, a temporary snapshot is created behind the scenes. This transient snapshot is invisible to Kubernetes, and is eventually deleted by VAST Block CSI Driver once the clone operation is complete.
As with regular volumes, VAST CSI Driver automatically creates a view and a quota for the resulting clone volume on the VAST cluster. The clone is mounted to the underlying directory of the view and can be used for read and write operations. It can also be expanded through Kubernetes volume expansion.
Note: Cloning is done using Global Snapshot Clones, a feature of VAST Cluster 4.6.0 and later. For more information about this feature, see VAST Cluster Administrator's Guide.
To clone a block volume from its snapshot:
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Create a YAML configuration file for cloning and specify the following required parameters:
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In
metadata:nameis the Persistent Volume Claim (PVC) name for the clone.
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In
spec:-
storageClassNameis the name of the storage class used for the PVC. -
In
dataSource:nameis the PVC name of the block volume that stores the snapshot from which cloning is done.
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For example:
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: pvc-clone spec: accessModes: - ReadWriteOnce resources: requests: storage: 10Gi storageClassName: vastdata-filesystem dataSource: name: snapshot-pvc-1snap kind: VolumeSnapshot apiGroup: snapshot.storage.k8s.io -
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Deploy the YAML configuration file:
kubectl apply -f vast-csi-deployment.yamlThe output is similar to the following:
persistentvolumeclaim/pvc-clone created -
Verify that the clone can be displayed:
kubectl get pvcThe output is similar to the following:
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE pvc-clone Bound pvc-c212dc9e-1b72-49da-8a58-8c1ceb97b9e3 1Gi RWX vastdata-filesystem 7s