* Created a new `dryRun` query parameter for mutating endpoints. If the parameter is set, then the query will be rejected, as the feature is not implemented yet. This will allow forward compatibility with future clients; otherwise, future clients talking with older apiservers might end up modifying a resource even if they include the `dryRun` query parameter. ([#63557](https://github.com/kubernetes/kubernetes/pull/63557), [@apelisse](https://...

* Bump Heapster to v1.6.0-beta.1 ([#67074](https://github.com/kubernetes/kubernetes/pull/67074), [@kawych](https://github.com/kawych))

- `diskformat` storage class parameter for in-tree vSphere volume plugin is deprecated as of v1.21 release. Please consider updating storageclass and remove `diskformat` parameter. vSphere CSI Driver does not support diskformat storageclass parameter.
  

* Fixed pod cleanup when /var/lib/kubelet is a symlink. ([#68741](https://github.com/kubernetes/kubernetes/pull/68741), [@jsafrane](https://github.com/jsafrane))
* Add "only_cpu_and_memory" GET parameter to /stats/summary http handler in kubelet. If parameter is true then only cpu and memory will be present in response. ([#67829](https://github.com/kubernetes/kubernetes/pull/67829), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

administrators will be able to place limits by using the new kubelet command line parameter --pod-max-pids. Note that since this is a alpha feature they will need to enable the "SupportPodPidsLimit" feature. By default, we do not set any maximum limit, If an administrator wants to enable this, they should enable SupportPodPidsLimit=true in the --feature-gates= parameter to kubelet and specify the limit using the --pod-max-pids parameter. The limit set is the total count of all processes running in all containers...

* Parameter keys in a StorageClass `parameters` map may not use the `kubernetes.io` or `k8s.io` namespaces. ([#41837](https://github.com/kubernetes/kubernetes/pull/41837), [@liggitt](https://github.com/liggitt))

* ScaleIO persistent volumes now support referencing a secret in a namespace other than the bound persistent volume claim's namespace; this is controlled during provisioning with the `secretNamespace` storage class parameter; StoragePool and ProtectionDomain attributes no longer defaults to the value `default` ([#54013](https://github.com/kubernetes/kubernetes/pull/54013), [@vladimirvivien](https://github.com/vladimirvivien))

  * You must install the Ceph CSI driver (rbd.csi.ceph.com), v3.5.0 or above, into your Kubernetes cluster.

- MaxUnavailable for StatefulSets, allows faster RollingUpdate by taking down more than 1 pod at a time. The number of pods you want to take down during a RollingUpdate is configurable using maxUnavailable parameter. ([#82162](https://github.com/kubernetes/kubernetes/pull/82162), [@krmayankk](https://github.com/krmayankk))

#### Storage