De link
For customers that want to have a highly virtualized environment, Windows Server 2012 R2 Datacenter edition is the right edition to use. Windows Server 2012 R2 Datacenter edition will allow you to run unlimited virtual instances with each license on a single server. This allows you to grow as much as you need to, and with no limit there is no need to track how many instances you are running to ensure that you are compliant.
Além disso, leia sobre Ativação automática de máquina virtual (AVMA), nova no Server 2012:
Practical Applications [of AVMA]
On virtualization servers that are activated using Volume Licensing or OEM licensing, AVMA offers several benefits.
Server datacenter managers can use AVMA to do the following:
• Activate virtual machines in remote locations
• Activate virtual machines with or without an internet connection
• Track virtual machine usage and licenses from the virtualization server, without requiring any access rights on the virtualized systems
There are no product keys to manage and no stickers on the servers to read. The virtual machine is activated and continues to work even when it is migrated across an array of virtualization servers.
Service Provider License Agreement (SPLA) partners and other hosting providers do not have to share product keys with tenants or access a tenant’s virtual machine to activate it. Virtual machine activation is transparent to the tenant when AVMA is used. Hosting providers can use the server logs to verify license compliance and to track client usage history.