When Azure virtual machine scale sets were introduced, we made it easy to deploy and manage cloud infrastructure at very large scale. We are continually looking for ways to lower the overall cost of managing cloud infrastructure. One area of cost that increases with scale is maintaining each virtual machine patched to the latest OS version, while keeping your applications running. This means finding ways to smoothly roll out an upgrade, one batch of VMs at a time. Many OS providers create new patched versions of their VM images at a monthly cadence, or more frequently for critical security fixes, but checking for, and manually rolling out these upgrades adds to cloud infrastructure management cost.
Now in preview, the automatic OS image upgrade feature for Azure scale sets will automatically upgrade all VMs in your scale set to the latest version. Once configured, the latest OS image published by image publishers will automatically be applied to the scale set without user intervention.
To learn more about how to register your subscription for the preview and to get started, please read Azure virtual machine scale set automatic OS upgrades.