Using a Microsoft Azure VM as a DAG witness server

Exchange Server 2013 enables you to configure your mailbox databases in a database availability group (DAG) for automatic datacenter failover. This configuration requires three separate physical locations: two datacenters for mailbox servers and a third location to place the witness server for the DAG.

RVTools

This application supports ESX Server 3.5 VirtualCenter 2.5 ESX Server 3i ESX Server 4i VirtualCenter 4.x ESX 4.x, VirtualCenter 5.0  VirtualCenter Appliance, ESX 5.0, VirtualCenter 5.1, ESX 5.1, VirtualCenter 5.5 and ESX 5.5. Documentation Full Article Download the tool here