- Fixed a bug which kubectl would emit duplicate warning messages for flag names that contain an underscore and recommend using a nonexistent flag in some cases. ([#103852](https://github.com/kubernetes/kubernetes/pull/103852), [@brianpursley](https://github.com/brianpursley))

## Known Issues

## Urgent Upgrade Notes

versions. Dormant StatefulSets with the annotation set to `false` will become active after upgrading.

* The CronJob object is now enabled by default at `v1beta1`. CronJob `v2alpha1` is still available, but it must be explicitly enabled. We recommend that you move any current CronJob objects to `batch/v1beta1.CronJob`. Be aware that if you specify the deprecated version, you may encounter Resource Not Found errors. These errors occur because the new controllers look for the new version during...

API. With that design, the QoS class for a pod only applied to CPU resources (such as `cpu_shares`). The Kubernetes cgroup manager uses `memory.limit_in_bytes` in v1 cgroups to limit the memory capacity for a container, and uses `oom_scores` to recommend an order for killing container processes if an out-of-memory event occurs. This implementation has shortcomings: for `Guaranteed` pods, memory can not be fully reserved, and the page cache is at risk of being recycled. For `Burstable` pods, overcommitting...

  The `--` separator has been recommended since the Kubernetes v1.18 release, which also deprecated the legacy way of invoking `kubectl exec`.
  
  This change aligns with the deprecation of legacy `kubectl exec` command execution and enforces the use of `kubectl exec [POD] -- [COMMAND]` for improved compatibility and adherence to recommended practices."

    - [Server Binaries](#server-binaries-11)
    - [Node Binaries](#node-binaries-11)
  - [1.9 Release Notes](#19-release-notes)
  - [WARNING: etcd backup strongly recommended](#warning-etcd-backup-strongly-recommended)
  - [Introduction to 1.9.0](#introduction-to-190)
  - [Major themes](#major-themes)
    - [API Machinery](#api-machinery)
    - [Apps](#apps)
    - [Auth](#auth)
    - [AWS](#aws)

- [v1.6.0](#v160)
  - [Downloads for v1.6.0](#downloads-for-v160)
    - [Client Binaries](#client-binaries-13)
    - [Server Binaries](#server-binaries-13)
  - [WARNING: etcd backup strongly recommended](#warning-etcd-backup-strongly-recommended)
  - [Major updates and release themes](#major-updates-and-release-themes)
  - [Action Required](#action-required-1)
    - [Certificates API](#certificates-api)

- The certificate signer no longer accepts ca.key passwords via the `CFSSL_CA_PK_PASSWORD` environment variable. This capability was not prompted by user request, never advertised, and recommended against in the security audit. ([#84677](https://github.com/kubernetes/kubernetes/pull/84677), [@mikedanese](https://github.com/mikedanese))

  
  VM Hardware version less than 15 is deprecated as of v1.21. Please consider upgrading the Node VM Hardware version to 15 or above. vSphere CSI Driver recommends Node VM's Hardware version set to at least vmx-15.