### Volumes
* **[stable]** StorageClass API is promoted to v1 (storage.k8s.io/v1).
* **[stable]** Default storage classes are deployed during installation on Azure, AWS, GCE, OpenStack and vSphere.
* **[stable]** Added ability to populate environment variables from a configmap or secret.

* New alpha feature limits the number of processes running in a pod. Cluster 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...

- Label `apps.kubernetes.io/pod-index` added to Pod from StatefulSets is promoted to stable
  Label `batch.kubernetes.io/job-completion-index` added to Pods from Indexed Jobs is promoted to stable ([#128387](https://github.com/kubernetes/kubernetes/pull/128387), [@alaypatel07](https://github.com/alaypatel07)) [SIG Apps]

all` or just `kubeadm init` will now generate the new `super-admin.conf` file. The cluster admin can then decide to keep the file present on a node host or move it to a safe location. `kubadm certs renew` will renew the certificate in `super-admin.conf` to one year if the file exists; if it does not exist a "MISSING" note will be printed. `kubeadm upgrade apply` for this release will migrate this particular node to the two file setup. Subsequent kubeadm releases will continue to optionally renew the...

* [stable] The PV spec for Azure File, CephFS, iSCSI, and Glusterfs is modified to reference namespaced resources.

* [stable] You can now customize the iSCSI initiator name per volume in the iSCSI volume plugin.

* [stable] You can now specify the World Wide Identifier (WWID) for the volume identifier in the Fibre Channel volume plugin.

* [beta] Reclaim policy in StorageClass

* kube-apiserver: `--runtime-config` can once again be used to enable/disable serving specific resources in the `extensions/v1beta1` API group. Note that specific resource enablement/disablement is only allowed for the `extensions/v1beta1` API group for legacy reasons. Attempts to enable/disable individual resources in other API groups will print a warning, and will return an error in future releases. ([#72249](https://github....

for the kubelet in the dropin, a structured configuration file for the kubelet is used, and is expected to be present in `/var/lib/kubelet/config.yaml`. For runtime-detected, instance-specific configuration values, a environment file with dynamically-generated flags at `kubeadm init` or `kubeadm join` run time is used. Finally, if you want to override something specific for the kubelet that can't be done via the kubeadm Configuration file (which is preferred), you might add flags to the `KUBELET_EXTRA_ARGS`...

- Supporting Cross RG resources (disks, Azure File and node [Experimental]

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.

  using ethtool to disable checksum offload on your primary network interface, you should
  now be able to stop doing that. ([#92035](https://github.com/kubernetes/kubernetes/pull/92035), [@danwinship](https://github.com/danwinship)) [SIG Network and Node]

 
#### Configuration file changes:

#### kube-apiserver: