Windows Server 2012 licensing is based on the number of CPU’s and virtual machines that servers are running. This video looks at determining how many Windows Server 2012 licenses you will need and how you can transfer licenses from one server to another server.
License Per Edition
Windows Server 2012 comes in 4 different editions. Depending on which edition that you purchase will determine how many CPU’s that server can run and how many virtual instances of that operating system that you can run on that server. If you perform a physical install on Windows Server 2012, you must run any virtual instances for that server on the same server that the physical install is on.
Datacenter and standard essentially have the same features as each other, the only real difference between the two editions is that DataCenter supports an unlimited number of virtual machines, while Standard supports 2.
Essentials edition differs from the other editions in that the install can only be performed in a virtual or physical machine. This is essentially because there is only one virtual instance supported and also Essentials edition does not support the Hyper-V role.
Each edition of Windows Server 2012 allows 2 CPU’s to be installed in the server except for the Foundation edition which only allows one CPU to be used in the server. The Foundation install is also the only edition of Windows Server 2012 that does not allow the install to be performed in a virtual machine.
The CPU’s limit only relates to the number of physical CPU’s the computer has. Each CPU can have any number of cores.
Only Standard and Datacenter support more than 2 CPU’s in the server. If you want to add additional CPU’s you will need to purchase additional Windows Server 2012 licenses. Each license that you purchase will allow you to add 2 additional CPU’s to that server. The licenses you need to purchase need to be the same as the edition of Windows Server 2012.
For each copy of Windows Server 2012 Standard edition that you purchase you can run 2 virtual instances of Windows Server 2012 on that server. If you do use both Windows Server 2012 virtual licenses, the physical install of Windows Server 2012 on that server must be used only to manage the virtual instances. You can’t install additional roles on this physical server. You can use a different technology to run the virtual instances. For example, you could run VMware to run the virtual instances.
For each additional Windows Server 2012 Standard edition you purchase this will allow you to run 2 more additional Windows Server 2012 virtual servers.
Moving Virtual Server
You are free to move licenses between servers, however 90 days must past between moves. This prevents virtual machines being moved from server to server if the server was to be taken down for short term maintenance. If you wanted to do this, you would need to purchase additional licenses for the server that will be running the virtual instances while the server is down for maintenance.
This rule does not apply if the server experiences extreme hardware failure and was never to be brought back online again. If this is the case, the license can be moved from that server to the replacement server immediately.
“Installing and Configuring Windows Server 2012 Exam Ref 70-410” pg 3,6
“Introduction to Windows Server 2012 Foundation” http://technet.microsoft.com/en-us/library/jj679892.aspx
“Windows Server 2012” http://en.wikipedia.org/wiki/Windows_Server_2012
“Memory Limits for Windows Releases (Windows)” http://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx#physical_memory_limits_windows_server_2012K