In the last few months, I have received questions from a few Mirazon engineers about this topic so I figured it was time to cover the basics again. On top of that, the end of support for Windows Server 2003 is only a few months away and some businesses are looking for information on how to migrate to Windows Server 2012.
So how do virtualization rights work with Windows Server 2012?
Our discussion will be limited to the Standard and Datacenter versions of Windows Server. I know that Essentials and Foundation are also out there, but based on what Mirazon usually sells as a value-added reseller they are not very common…at least not for our customers.
In this post, I’ll cover the basics and in the next post we’ll talk about how to license your hosts to allow your VMs to move around your server farm legally.
There is both a physical and a virtual aspect to these licenses. On the physical side of the equation, a single license of either Standard or Datacenter will provide you with the right to run the product on up to two physical processors on a single server. Notice the limitations in that phrase. A single license will cover two processors, but if and only if those two processors are located in the same physical box. You cannot buy an individual license and assign it to one processor running in one host and another processor running in another host. If you have two physical hosts, you will need at least two licenses, even if you only have one processor in each box.
What happens if you have more than two physical processors in a single box? Then you just buy another license or two to cover the number of processors you have. So if you have a host with four CPUs, then you would assign two licenses to that host:
On the virtual side of the equation, a license of Standard will provide you with the right to run two virtual instances of the product on the licensed physical host. A license of Datacenter will provide you with the right to run an unlimited number of virtual instances on the licensed physical host. Again, notice the limitations. The license will be assigned to a certain physical host and will provide you with certain virtualization rights for that host.
What happens if you are using Standard, but you need more than two VMs? Again, you just buy another license or two to cover the number of VMs you have. Each license gives you the right to run an additional two VMs. So if necessary, you can license one host for six VMs by assigning three Standard licenses to that host. Alternatively, you can just purchase one license of Datacenter to cover those six VMs:
The next natural question is this: If Standard gives you the right to run two VMs and Datacenter gives you the right to run an unlimited number of VMs, at what point is it cheaper to buy Datacenter rather than Standard?
There must come a point where your quantity of VMs tips the scales in favor of buying Datacenter instead of just piling more and more Standard licenses on a single box. The answer will depend on your particular situation, but as an example we’ll crunch the numbers for a single host with a single processor buying licensing through the Open Business volume licensing program:
The MSRP of a Standard license (without SA) though the Open Business program is $883. The MSRP of Datacenter (without SA) through the same program is $6,156. A single license of Datacenter costs the same as seven licenses of Standard:
As you can see from the chart above, seven licenses of Standard will provide you with 14 VMs for a single physical host, so the answer to our question is 14 VMs. If you need to run 14 or more instances of Windows Server on a single host, then you are better off buying a single Datacenter license rather than stacking several licenses of Standard.
In my next post, I will cover how to license your environment so you can move VMs around while staying in compliance. In the meantime, you can download the licensing datasheet for Windows Server 2012 for more information on this topic.