To allow cgroups v1 with `kubeadm` and `kubelet` version `v1.35` or newer, you must:
  - Ignore the error from the SystemVerification preflight check by `kubeadm`.

- kubeadm: removed preflight check for nsenter on Linux nodes

([#72214](https://github.com/kubernetes/kubernetes/pull/72214), [@caesarxuchao](https://github.com/caesarxuchao))

- kubeadm
  - `kubeadm alpha preflight` and `kubeadm alpha preflight node` are removed; you can now use `kubeadm join phase preflight` ([#73718](https://github.com/kubernetes/kubernetes/pull/73718), [@fabriziopandini](https://github.com/fabriziopandini))

* New kubeadm flag `--ignore-preflight-errors` that enables to decrease severity of each individual error to warning. ([#56072](https://github.com/kubernetes/kubernetes/pull/56072), [@kad](https://github.com/kad))
    * Old flag `--skip-preflight-checks` is marked as deprecated and acts as `--ignore-preflight-errors=all`

- Kubeadm: Added support during the preflight check "CreateJob" of "kubeadm upgrade" to check if there are no nodes where a Pod can be scheduled. If there are none, show a warning and skip this preflight check. This can happen in single node clusters where the only node was drained. ([#124503](https://github.com/kubernetes/kubernetes/pull/124503), [@neolit123](https:/...

- Kubeadm: switch the preflight check (called 'Swap') that verifies if swap is enabled on Linux hosts to report a warning instead of an error. This is related to the graduation of the NodeSwap feature gate in the kubelet to Beta and being enabled by default in 1.23 - allows swap support on Linux hosts. In the next release of kubeadm (1.24) the preflight check will be removed, thus we recommend that you stop using it - e.g. via `--ignore-preflight-errors`...

* kubeadm will now pull required images during preflight checks if it cannot find them on the system. ([#64105](https://github.com/kubernetes/kubernetes/pull/64105), [@chuckha](https://github.com/chuckha))

- Kubeadm: during the preflight check "CreateJob" of "kubeadm upgrade", check if there are no nodes where a Pod can schedule. If there are none, show a warning and skip this preflight check. This can happen in single node clusters where the only node was drained. ([#124570](https://github.com/kubernetes/kubernetes/pull/124570), [@neolit123](https://gi...

- kubeadm: removed `socat` and `ebtables` from kubeadm preflight checks ([#127151](https://github.com/kubernetes/kubernetes/pull/127151), [@saschagrunert](https://github.com/saschagrunert)) [SIG Cluster Lifecycle]

- The flag `--skip-preflight-checks` of kubeadm has been removed. Please use `--ignore-preflight-errors` instead. ([#62727](https://github.com/kubernetes/kubernetes/pull/62727), [@xiangpengzhao](https://github.com/xiangpengzhao))