How to migrate to managed disks via Advisor :
You will notice in your VM that now you have an option to migrate to managed disk
This process STARTS/Stops the VM for at least 10 minutes plus restart. Beware doing this in high production servers.
Click in migrate an azure will do all the work for you
In the disk section you can see is “Updating”
You can be certain when the process finished looking into the DISK section/ Or into the Migration process
Here is an overview of all the benefits you get when Migrating old VHD drives: