Migrate your Azure unmanaged disks by September 30, 2025

  • Article

Applies to: ✔️ Linux VMs ✔️ Windows VMs

In 2017, we launched Azure managed disks. We've been enhancing capabilities ever since. Because Azure managed disks now have the full capabilities of unmanaged disks and other advancements, we'll begin deprecating unmanaged disks on September 13, 2022. This functionality will be fully retired on September 30, 2025.

With managed disks, you don't have to worry about managing storage accounts for creating a disk, because Azure manages the storage accounts under the hood. The abstraction reduces maintenance overhead for you. Also, it allows managed disks to provide numerous benefits over unmanaged disks, such as better reliability, scalability, large disks, bursting, and shared disks. If you use unmanaged disks, start planning your Windows or Linux migration now. Complete the migration by September 30, 2025, to take advantage of Azure managed disks.

How does this affect me?

  • As of January 30, 2024, new customers won't be able to create unmanaged disks.
  • On September 30, 2025, customers will no longer be able to start IaaS VMs by using unmanaged disks. Any VMs that are still running or allocated will be stopped and deallocated.

What is being retired?

Unmanaged disks are a type of page blob in Azure that is used for storing Virtual Hard Disk (VHD) files associated with virtual machines (VM). When a page blob VHD is attached to a VM, it functions as a virtual disk for that VM. The VM's operating system can read from and write to the attached page blob as if it were a SCSI volume. This retirement only affects page blobs being used as virtual disks that are directly attached to VMs.

Page blobs accessed directly via HTTP/HTTPS REST APIs are standalone entities and have no dependencies on any specific VM. Clients can interact with these page blobs using standard HTTP/HTTPS protocols, making requests to read from or write to the blobs using Storage REST APIs. Since these page blobs aren't attached as virtual disks, this retirement doesn't affect them.

Third party storage offerings on Azure that are using page blobs via HTTP/HTTPS REST APIs as their underlying storage solution may not be affected by this retirement.

What actions should I take?

Start planning your migration to Azure managed disks today.

  1. Make a list of all affected VMs:

    • The VMs with Uses managed disks set to No on the Azure portal's VM pane are all the affected VMs within the subscription.
    • You can also query Azure Resource Graph by using the portal or PowerShell to view the list of all flagged VMs and related information for the selected subscriptions.
    • On February 28, 2020, we sent out emails to subscription owners with a list of all subscriptions that contain these VMs. Use them to build this list.

  2. Learn more about migrating your VMs to managed disks. For more information, see Frequently asked questions about migrating to managed disks.

  3. For technical questions, issues, and help with adding subscriptions to the allowlist, contact support.

  4. Complete the migration as soon as possible to prevent business impact and to take advantage of the improved reliability, scalability, security, and new features of Azure managed disks.