Today we are announcing the general availability of platform managed IaaS migration of resources from classic to resource manager. All migration functionality released as a preview on May 12 is now generally available. In addition, we are also announcing the general availability of storage account migration from classic to Resource Manager.
With this release it is possible to migrate the most common classic Virtual Machine deployments in an existing classic virtual network to Azure Resource Manager without virtual machine downtime. Cloud services with all VMs in a single availability set, or cloud services with all VMs not part of an availability set can be migrated with a few exceptions (see unsupported features and configurations). Classic virtual machines, which are not part of a classic virtual network will undergo a single reboot operation when migrated to Resource Manager.
For a great video overview of the migration process please check out Corey Sanders in the below Microsoft Mechanics episode, Azure Classic to Azure Resource Manager Migration.