These extension points can now be abstracted away due to their irrelevance for most users.

### CSI Migration updates

CSI Migration enables the replacement of existing in-tree storage plugins such as `kubernetes.io/gce-pd` or `kubernetes.io/aws-ebs` with a corresponding CSI driver.
If CSI Migration is working properly, Kubernetes end users shouldn’t notice a difference.

  General Support for vSphere 6.7 will end on October 15, 2022. vSphere 6.7 Update 3 is deprecated in Kubernetes v1.24.  Customers are recommended to upgrade vSphere (both ESXi and vCenter) to 7.0u2 or above.  vSphere CSI Driver 2.2.3 and higher supports CSI Migration.

  // More info: https://examples.k8s.io/volumes/storageos/README.md
  // +optional
  optional StorageOSPersistentVolumeSource storageos = 21;

  // csi represents storage that is handled by an external CSI driver (Beta feature).
  // +optional
  optional CSIPersistentVolumeSource csi = 22;
}

// PersistentVolumeSpec is the specification of a persistent volume.
message PersistentVolumeSpec {

### Container Storage Interface graduations

CSI support for Windows nodes moves to GA in the 1.22 release. In Kubernetes v1.22, Windows privileged containers are only an alpha feature. To allow using CSI storage on Windows nodes, [CSIProxy](https://github.com/kubernetes-csi/csi-proxy) enables CSI node plugins to be deployed as unprivileged pods, using the proxy to perform privileged storage operations on the node.

    - [go1.15.5](#go1155)
    - [CSI Volume Snapshot graduates to General Availability](#csi-volume-snapshot-graduates-to-general-availability)
    - [Non-recursive Volume Ownership (FSGroup) graduates to Beta](#non-recursive-volume-ownership-fsgroup-graduates-to-beta)
    - [CSIDriver policy for FSGroup graduates to Beta](#csidriver-policy-for-fsgroup-graduates-to-beta)

  // More info: https://examples.k8s.io/volumes/storageos/README.md
  // +optional
  optional StorageOSPersistentVolumeSource storageos = 21;

  // csi represents storage that is handled by an external CSI driver (Beta feature).
  // +optional
  optional CSIPersistentVolumeSource csi = 22;
}

// PersistentVolumeSpec is the specification of a persistent volume.
message PersistentVolumeSpec {

	// +optional
	StorageOS *StorageOSVolumeSource `json:"storageos,omitempty" protobuf:"bytes,27,opt,name=storageos"`
	// csi (Container Storage Interface) represents ephemeral storage that is handled by certain external CSI drivers (Beta feature).
	// +optional
	CSI *CSIVolumeSource `json:"csi,omitempty" protobuf:"bytes,28,opt,name=csi"`
	// ephemeral represents a volume that is handled by a cluster storage driver.

### Promoted CSI Ephemeral Volume to Stable

* Fix setup of configmap/secret/projected/downwardapi volumes ([#64855](https://github.com/kubernetes/kubernetes/pull/64855), [@gnufied](https://github.com/gnufied))
* Added default ClusterRoles for external CSI components csi-external-provisioner and csi-external-attacher ([#65073](https://github.com/kubernetes/kubernetes/pull/65073), [@davidz627](https://github.com/davidz627))

#### Storage

- When PodInfoOnMount is enabled for a CSI driver, the new csi.storage.k8s.io/ephemeral parameter in the volume context allows a driver's NodePublishVolume implementation to determine on a case-by-case basis whether the volume is ephemeral or a normal persistent volume ([#79983](https://github.com/kubernetes/kubernetes/pull/79983), [@pohly](https://github.com/pohly))