We are planning an update to the Ubuntu image retention policy on Azure that will begin taking effect in late August 2026. While our current policy retains the last 90 release images per plan or SKU, the new policy will retain the last 20 versions (keeping at least six months of images). This will not disrupt running VMs, but will reduce the number of images older than six months that can be used for new launches. It will also affect Virtual Machine Scale Sets (VMSS) pinned to very old images.
Before these changes are finalized, we want to make sure this transition doesn’t disrupt your active deployment pipeline. Although version pinning introduces long-term security and maintenance challenges, we recognize it is often used to ensure predictability. We believe that retaining at least six months of images will give our customers sufficient time to roll out updated images to even very complicated estates. If your specific workflow relies on pinning older builds because a viable alternative isn’t available, please share your use case below so we can understand the requirement.
A few details on the updated policy:
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Active release plans. We will retain the last 20 release image versions under each active offer SKU.
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Plans past standard maintenance. For SKUs under plans that no longer receive active image updates (such as free public plans for releases that have transitioned out of their standard five-year window), we will continue to retain only a single, final image version.
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The six-month safeguard. No image version less than six months old will be removed, ensuring recent builds remain available regardless of the 20-image threshold.
How this affects your infrastructure
Running virtual machines are completely unaffected and will continue to operate normally. Once an older version is removed, you simply won’t be able to deploy new instances using that specific historical image version.
The main item for administrators to review is VMSS. If a scale set is explicitly pinned to an older image version that gets removed, the VMSS will fail to scale out during a scale event. If your automated templates rely on specific older versions, we recommend updating them to a newer valid version or transitioning them to use the latest tag.
Please let us know if you have any questions or specific deployment concerns in the comments below.