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Add blog on shifting to cgroup v2 after cgroup v1 deprecation in v1.35 - #56945

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pacoxu:cgroupv2-blog-2026
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Add blog on shifting to cgroup v2 after cgroup v1 deprecation in v1.35#56945
pacoxu wants to merge 6 commits into
kubernetes:mainfrom
pacoxu:cgroupv2-blog-2026

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@pacoxu

@pacoxu pacoxu commented Aug 12, 2026 •
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Description

Preview: https://deploy-preview-56945--kubernetes-io-main-staging.netlify.app/blog/2026/08/20/kubernetes-cgroups-v2-shift/

This PR is based on #47342.

I will update according to latest changes around cgroup v2/v1.

Issue

Closes: None

Table of contents

  • Deprecation of cgroup v1
  • Limitations of cgroup v1 and improvements with cgroup v2
    • active_file memory handling
    • Memory QoS updates in Kubernetes v1.36
    • Container-aware OOM handling
    • Rootless support and Pod user namespaces
    • PSI, eBPF, and migration considerations
    • CPU weight conversion in newer OCI runtimes
    • In-place resource updates
  • Adopting cgroup v2
    • Requirements
    • Linux kernel updates
    • Using the systemd cgroup driver
    • Troubleshooting tools and commands
  • Further reading

@kubernetes-prow kubernetes-prow Bot added cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. size/L Denotes a PR that changes 100-499 lines, ignoring generated files. labels Aug 12, 2026
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kubernetes-prow Bot requested a review from Gauravpadam August 12, 2026 09:57
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kubernetes-prow Bot commented Aug 12, 2026

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kubernetes-prow Bot requested a review from lmktfy August 12, 2026 09:57
@kubernetes-prow kubernetes-prow Bot added area/blog Issues or PRs related to the Kubernetes Blog subproject language/en Issues or PRs related to English language labels Aug 12, 2026
@pacoxu pacoxu mentioned this pull request Aug 12, 2026
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@pacoxu

pacoxu commented Aug 12, 2026

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/cc @kannon92 @neolit123 @sohankunkerkar @KentaTada

Sorry for the delay.
I picked up this blog post again and updated it for the latest v1.35/v1.36 changes.

Since you reviewed the original PR #47342 two years ago, would you mind giving it another quick look when you get a chance?

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@pacoxu: GitHub didn't allow me to request PR reviews from the following users: KentaTada.

Note that only kubernetes members and repo collaborators can review this PR, and authors cannot review their own PRs.

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In response to this:

/cc @kannon92 @neolit123 @sohankunkerkar @KentaTada

Sorry for the delay.
I picked up this blog post again and updated it for the latest v1.35/v1.36 changes.

Since you reviewed the original PR #47342 two years ago, would you mind giving it another quick look when you get a chance?

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

@pacoxu
pacoxu force-pushed the cgroupv2-blog-2026 branch from 8e31cce to 8d3ede4 Compare August 12, 2026 10:36
pacoxu
pacoxu commented Aug 12, 2026
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Comment thread content/en/blog/_posts/2026-08-20-migrate-cgroup-v2.md
---
layout: blog
title: 'The Shift to cgroup v2 in Kubernetes: What You Need to Know'
draft: true

@pacoxu pacoxu Aug 12, 2026

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update draft=false, once the blog is ready and publish date is confirmed.

neolit123
neolit123 reviewed Aug 12, 2026
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LGTM, just one inline comment.
also a question - should we mention that we now have strict validation for cgroups v2 from the system-validators lib?

Comment thread content/en/blog/_posts/2026-08-20-migrate-cgroup-v2.md
memory requests and limits for containers that perform intensive I/O, after measuring an appropriate
value.

### Memory QoS updates in Kubernetes v1.36

@neolit123 neolit123 Aug 12, 2026

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i recommend adding a note how memoryqos relates to cgroups v2.

@pacoxu pacoxu Aug 13, 2026

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Add a simple intro for kubeadm/system-validators check and why memory QoS needs cgroup v2 as a note.

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@Gauravpadam Gauravpadam Awaiting requested review from Gauravpadam
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