Azure Managed Disks 2 – Conversion

In my last post, I discussed the advantages of Azure Managed Disks and briefly mentioned that it is possible to convert from Storage Account to Managed Disks, but made no reference as to how this was achieved.

Advantages to converting to Managed Disks include:

  • Improved Availability
  • Improved Management
  • Ability to switch from Premium to Standard, or Standard to Premium
  • Ease of resizing VM Disks
  • No dependency on Storage Accounts

There is extensive documentation on the subject on the Microsoft Documentation site: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/convert-unmanaged-to-managed-disks

A key thing to know is that this is a downtime event. Even if you have your VMs in an Availability Set, they need to be fully deallocated as part of the migration process. This is due to the fact that the Availability Set needs to be migrated to the “aligned” SKU that is a prerequisite for Managed Disks (which has the side benefit of increasing the VM availability). Additionally, if Server Side Encryption is enabled, you can’t convert the disk.

The process is quite simple – stop your VM, run the ConvertTo-AzureRMVMMangedDisk PowerShell cmdlet, and you’re on your way.