Microsoft has warned that Azure Linux 2.0, used in Azure Kubernetes Service (AKS) enabled by Azure Arc, will reach its end of life on July 31, 2025, necessitating users to upgrade. After this date, Microsoft will no longer provide updates, security patches, or support for Azure Linux 2.0. The longer it is used after this date, the more vulnerable systems will become due to a lack of patches.
Azure Linux 3.0 brings significant upgrades to core components that enhance performance, security, and the developer experience. The Linux kernel is upgraded from version 5.15 to 6.6, bringing performance and hardware compatibility improvements. The Containerd package has been updated from version 1.6.26 to 1.7.13, improving container management.
The SystemD package has been upgraded from version 250 to 255, streamlining system and service management, and OpenSSL has jumped from version 1.1.1k to 3.3.0, providing enhanced encryption and security. Azure Linux 3.0 also brings more packages and better tooling.
Major versions of Azure Linux are typically supported for three years, with Azure Linux 3.0’s EOL projected for Summer 2027. It became generally available in August 2024.Microsoft said that users must migrate to Azure Linux 3.0 by upgrading their Azure Local instances to the 2507 release when it becomes available.
After the Azure Local instance has been upgraded, users can then upgrade their Kubernetes clusters. Microsoft gives you the option to remain on the same Kubernetes version during this upgrade by providing the same version number on the aksarc upgrade command. After upgrading, you can verify the kernel version on your Linux nodes by adjusting the file path in this command: kubectl --kubeconfig /path/to/aks-cluster-kubeconfig get nodes -o wide
This upgrade is mandatory for continued support. If you want to learn more, check out Microsoft’s announcement which also includes how to reach out to the AKS Arc team if you need to.