* --google-json-key
    * --log_cadvisor_usage
    * --machine_id_file
    * --storage_driver_user
    * --storage_driver_password
    * --storage_driver_host
    * --storage_driver_db
    * --storage_driver_table
    * --storage_driver_secure
    * --storage_driver_buffer_duration

([#57613](https://github.com/kubernetes/kubernetes/pull/57613), [@mtaufen](https://github.com/mtaufen))

  as it requires installation of AzureFile CSI Driver. Users should enable CSIMigration and
  CSIMigrationAzureFile features and install the [AzureFile CSI Driver](https://github.com/kubernetes-sigs/azurefile-csi-driver)
  to avoid disruption to existing Pod and PVC objects at that time. Azure File CSI driver does not support using same persistent

- Unlocked the `CSIMigrationvSphere` feature gate.
  The change allow users to continue using the in-tree vSphere driver,pending a vSphere
  CSI driver release that has with GA support for Windows, XFS, and raw block access. ([#116342](https://github.com/kubernetes/kubernetes/pull/116342), [@msau42](https://github.com/msau42)) [SIG Storage]

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))

- Promote CSIMigrationOpenStack to Beta (off by default since it requires installation of the OpenStack Cinder CSI Driver. The in-tree AWS OpenStack Cinder driver "kubernetes.io/cinder" was deprecated in 1.16 and will be removed in 1.20. Users should enable CSIMigration + CSIMigrationOpenStack features and install the OpenStack Cinder CSI Driver (https://github.com/kubernetes/cloud-provider-openstack) to avoid disruption to existing Pod and PVC objects at that time. Users should...

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

* [alpha] Improve Flex volume deployment

  * Flex volume driver deployment is simplified in the following ways:

    * New driver files can now be automatically discovered and initialized without requiring a kubelet or controller-manager restart.

    * A sample DaemonSet to deploy Flexvolume drivers is now available.

## Known Issues

feature gate is enabled, user should not upgrade to Kubernetes v1.22. vSphere CSI Driver does not support Kubernetes v1.22 yet because it uses v1beta1 CRD APIs. Support for v1.22 will be added at a later release. Check the following document for supported Kubernetes releases for a given [vSphere CSI Driver version](https://vsphere-csi-driver.sigs.k8s.io/compatiblity_matrix.html#compatibility-matrix-for-vsphere-csi-driver).

### Workloads that saturate nodes with pods may see pods that fail...

- Set CSIMigrationvSphere feature gates to beta.
  Users should enable CSIMigration + CSIMigrationvSphere features and install the vSphere CSI Driver (https://github.com/kubernetes-sigs/vsphere-csi-driver) to move workload from the in-tree vSphere plugin "kubernetes.io/vsphere-volume" to vSphere CSI Driver.