If you have an Azure VM that was created using the Azure Resource Manager (ARM) stack you can now easily resize the OS or the data disk within the Azure Portal. Of course, you can also use PowerShell but way too easy using the GUI.
2. Shutdown the VM from the Azure portal. Make sure it’s completely shutdown (de-allocated)
That’s it! You can login to the VM and check that you have the new selected size for the disk(s).
DISCLAIMER: The above blog posting is provided “AS IS” with no warranties and confers no rights.