A common challenge for customers running Kubernetes is keeping up with the rapid pace of bug fixes and security updates for all the software running on their clusters. To help address this, in April last year, Azure Kubernetes Service (AKS) added support for Long Term Support (LTS) for certain Kubernetes versions. Based on overwhelming customer feedback, the Azure Linux team is excited to announce that Azure Linux 2.0 will support AKS LTS for v1.27. With Azure Linux support for AKS LTS, customers benefit from having a stable and regularly serviced node operating system in addition to Kubernetes. To get started, simply run the following commands:

Create new Azure Linux cluster with LTS support enabled

az aks create --resource-group myResourceGroup --name myAKSCluster --tier premium --k8s-support-plan AKSLongTermSupport --kubernetes-version 1.27 --os-sku AzureLinux

Update an existing Azure Linux cluster to add LTS support

az aks update --resource-group myResourceGroup --name myAKSCluster --tier premium --k8s-support-plan AKSLongTermSupport

What are the benefits of Azure Linux support for AKS LTS?

• Customers can benefit from having a stable Kubernetes version as well as a stable OS version receiving security patches for the whole duration (July 2025).
• Components like the kernel, containerd, and systemd will all remain on stable versions receiving backported patches where necessary.
• This significantly reduces the risk of breaking changes or compatibility issues that may arise from upgrading critical OS components along with the Kubernetes version.

Any gotchas?

• One notable caveat is that Azure Linux did not switch to using cgroupsv2 until AKS version 1.29 due to issues with memory accounting in runc  with older versions that was patched with runc version (1.1.9) incorporated in Kubernetes v1.29. Therefore, cgroupsv1 remains the default on AKS version 1.27 for the extended support duration. Customers who want to use cgroupsv2 features or applications that require cgroupsv2 will need to upgrade to a newer AKS version that supports Azure Linux with cgroupsv2.

How to get started with Azure Linux support for AKS LTS?

• Support for Azure Linux with LTS is rolling out with the 2024-04-28 release. Please check the release tracker for the availability of the release in specific regions.
• To get started with Azure Linux support for AKS LTS, customers can create a new AKS cluster with Azure Linux 2.0 as the OS and AKS version 1.27 as the Kubernetes version or upgrade their existing AKS clusters to AKS version 1.27 and Azure Linux 2.0.
• To learn more about Azure Linux support for AKS LTS, customers can visit the AKS LTS documentation page.
• If there are any issues, customers can file an issue with the AKS GitHub Repo or open a support case.