Software licensing
Virtualization and clustering introduce potentially complex licensing considerations. The first issue you'll deal with is how to license your guest operating systems. Next, you'll consider the applications that will run on them.
Windows Server and guest virtualization rights
Microsoft has dramatically simplified their licensing scheme beginning with Windows Server 2012. Two of the editions, Standard and Datacenter, include guest virtualization rights with each license sold. Standard edition provides for two guests while Datacenter allows an unlimited number of guests. It is important to understand how these work as licensing may influence the number of physical hosts that you purchase.
The terms that Microsoft uses in its licensing documentation to distinguish the operating system that is installed directly on hardware from virtualized guest operating systems are Physical Operating System Environment (OSE) and Virtual OSE, respectively. These terms are rarely used in other...
