volume type when the kubelet was started, affecting the following volume types
  when the corresponding csi driver was installed:
  - `awsElasticBlockStore` for `ebs.csi.aws.com`
  - `azureDisk` for `disk.csi.azure.com`
  - `gcePersistentDisk` for `pd.csi.storage.googleapis.com`
  - `cinder` for `cinder.csi.openstack.org`
  - `csi`

### Promoted CSI Ephemeral Volume to Stable

- Fixed an issue where a CSI migrated volume may be prematurely detached when the CSI driver is not running on the node.

- CephRBD volume plugin ( `kubernetes.io/rbd`) was removed in this release. And its csi migration support was also removed, so the `rbd` volume type became non-functional. Alternative is to use RBD CSI driver (https://github.com/ceph/ceph-csi/) in your Kubernetes Cluster. A re-deployment of your application is required to use the new driver if you were using `kubernetes.io/rbd` volume plugin before upgrading cluster...

#### 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))

 - [Action Required] CSI drivers that call IsLikelyNotMountPoint should not assume false means that the path is a mount point. Each CSI driver needs to make sure correct usage of return value of IsLikelyNotMountPoint because if the file is an irregular file but not a mount point is acceptable ([#129370](https://github.com/kube...

 - Deprecated support for CSI migration of `Ceph RBD volumes`. Users who were relying on Kubernetes' ability

- Kubelet detected terminal CSI volume mount failures due to exceeded attachment limits on the node and marked the Stateful Pod as Failed, allowing its controller to recreate it. This prevented Pods from getting stuck indefinitely in the `ContainerCreating` state. ([#132933](http...

- Remove check for CSI driver running on node for CSI migration ([#115772](https://github.com/kubernetes/kubernetes/pull/115772), [@sunnylovestiramisu](https://github.com/sunnylovestiramisu)) [SIG Apps and Storage]

  by default. The CSI drivers can make use of the `secretRef` values passed in `NodeExpansion`
  request optionally sent by the CSI Client from this release onwards. ([#121303](https://github.com/kubernetes/kubernetes/pull/121303), [@humblec](https://github.com/humblec))