- Clarified help message of `--ignore-not-found` flag. Supported `--ignore-not-found` in `watch` operation. ([#132542](https://github.com/kubernetes/kubernetes/pull/132542), [@gemmahou](https://github.com/gemmahou))

### CSI Service Account Token

CSI Service Account Token feature moves to Beta in 1.21. This feature improves the security posture and allows CSI drivers to receive pods' [bound service account tokens](https://github.com/kubernetes/enhancements/blob/master/keps/sig-auth/1205-bound-service-account-tokens/README.md). This feature also provides a knob to re-publish volumes so that short-lived volumes can be refreshed.

### CSI Health Monitoring

  * Advanced scheduling can be performed with [taints and tolerations](https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#taints-and-tolerations-beta-feature)
* You can now specify (per pod) how long a pod should stay bound to a node, when there is a node problem.
* Various storage features have graduated to GA:
  * StorageClass pre-installed and set as default on Azure, AWS, GCE, OpenStack, and vSphere

   * that entries are indexable using ints.
   */
  static final int MAXIMUM_CAPACITY = Ints.MAX_POWER_OF_TWO;

  /** The maximum number of segments to allow; used to bound constructor arguments. */
  static final int MAX_SEGMENTS = 1 << 16; // slightly conservative

  /** Number of (unsynchronized) retries in the containsValue method. */
  static final int CONTAINS_VALUE_RETRIES = 3;

- Fixed mixed protocol issue for Azure load balancer ([#74200](https://github.com/kubernetes/kubernetes/pull/74200), [@andyzhangx](https://github.com/andyzhangx))
- Fixed Azure accounts timeout issue when there is no out-bound IP ([#74191](https://github.com/kubernetes/kubernetes/pull/74191), [@andyzhangx](https://github.com/andyzhangx))

http://kubernetes.io/docs/user-guide/persistent-volumes/ ## persistence: enabled: true annotations: {} ## A manually managed Persistent Volume and Claim ## Requires persistence.enabled: true ## If defined, PVC must be created manually before volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName...

http://kubernetes.io/docs/user-guide/persistent-volumes/ ## persistence: enabled: true annotations: {} ## A manually managed Persistent Volume and Claim ## Requires persistence.enabled: true ## If defined, PVC must be created manually before volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName...

http://kubernetes.io/docs/user-guide/persistent-volumes/ ## persistence: enabled: true annotations: {} ## A manually managed Persistent Volume and Claim ## Requires persistence.enabled: true ## If defined, PVC must be created manually before volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName...

http://kubernetes.io/docs/user-guide/persistent-volumes/ ## persistence: enabled: true annotations: {} ## A manually managed Persistent Volume and Claim ## Requires persistence.enabled: true ## If defined, PVC must be created manually before volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName...

http://kubernetes.io/docs/user-guide/persistent-volumes/ ## persistence: enabled: true annotations: {} ## A manually managed Persistent Volume and Claim ## Requires persistence.enabled: true ## If defined, PVC must be created manually before volume will be bound existingClaim: "" ## minio data Persistent Volume Storage Class ## If defined, storageClassName: <storageClass> ## If set to "-", storageClassName: "", which disables dynamic provisioning ## If undefined (the default) or set to null, no storageClassName...