Add documentation for VolumeSnapshot Beta (#17233)

content/en/docs/concepts/storage/volume-snapshot-classes.md

@@ -1,9 +1,11 @@
 ---
 reviewers:
-- jsafrane
 - saad-ali
 - thockin
 - msau42
+- jingxu97
+- xing-yang
+- yuxiangqian
 title: Volume Snapshot Classes
 content_template: templates/concept
 weight: 30
@@ -28,7 +30,7 @@ way to describe the "classes" of storage when provisioning a volume snapshot.
 
 ## The VolumeSnapshotClass Resource
 
-Each `VolumeSnapshotClass` contains the fields `snapshotter` and `parameters`,
+Each `VolumeSnapshotClass` contains the fields `driver`, `deletionPolicy`, and `parameters`,
 which are used when a `VolumeSnapshot` belonging to the class needs to be
 dynamically provisioned.
 
@@ -41,23 +43,30 @@ Administrators can specify a default `VolumeSnapshotClass` just for VolumeSnapsh
 that don't request any particular class to bind to.
 
 ```yaml
-apiVersion: snapshot.storage.k8s.io/v1alpha1
+apiVersion: snapshot.storage.k8s.io/v1beta1
 kind: VolumeSnapshotClass
 metadata:
   name: csi-hostpath-snapclass
-snapshotter: csi-hostpath
+driver: hostpath.csi.k8s.io 
+deletionPolicy: Delete
 parameters:
 ```
 
-### Snapshotter
+### Driver
 
-Volume snapshot classes have a snapshotter that determines what CSI volume plugin is
+Volume snapshot classes have a driver that determines what CSI volume plugin is
 used for provisioning VolumeSnapshots. This field must be specified.
 
+### DeletionPolicy
+
+Volume snapshot classes have a deletionPolicy. It enables you to configure what happens to a `VolumeSnapshotContent` when the `VolumeSnapshot` object it is bound to is to be deleted. The deletionPolicy of a volume snapshot can either be `Retain` or `Delete`. This field must be specified.
+
+If the deletionPolicy is `Delete`, then the underlying storage snapshot will be deleted along with the `VolumeSnapshotContent` object. If the deletionPolicy is `Retain`, then both the underlying snapshot and `VolumeSnapshotContent` remain.
+
 ## Parameters
 
 Volume snapshot classes have parameters that describe volume snapshots belonging to
 the volume snapshot class. Different parameters may be accepted depending on the
-`snapshotter`.
+`driver`.
 
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