Is there way to manually upgrade VMSS instances to a specific version of an OS?

Question

We have a VM Scale Set that currently uses Ubuntu 18.04, whose end of life is on May 20th 2023. We want to upgrade to Ubuntu 20.04. I checked the Azure Portal and VMSS CLI and didn't find a way to start an OS upgrade to a specific image version.

On Azure portal, there is only a button for OS upgrades with no options:

According to VMSS CLI docs, it seems to be possible to upgrade to the latest version of the OS only: https://learn.microsoft.com/en-us/cli/azure/vmss/rolling-upgrade?view=azure-cli-latest.

Answer 1

Hi @youssef sabih

When you have the automatic operating system image update feature activated on your scale set, there is no requirement for you to initiate image enhancements on your scale set manually. The operating system update coordinator will autonomously implement the most recent image version to your scale set units, eliminating the need for any manual input.

For specific cases where you do not want to wait for the orchestrator to apply the latest image, there 3 different ways in the official document below:

Reference: https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-upgrade#manually-trigger-os-image-upgrades

You can provision a VM and do the step by step described in this article, and create a new image for your VMSS
https://learn.microsoft.com/en-us/azure/machine-learning/data-science-virtual-machine/ubuntu-upgrade?view=azureml-api-2

Get in touch if you need more help with this issue.

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