Skip navigation

Summary of requirements for Windows Server licensed per processor under SPLA:

1.     You need a license for each physical CPU

2.     You also need a license for each vCPU

Exceptions & qualifications to the above for Enterprise Edition:

EE allows up to 4 VMs per licensed server, but this right is misleading as SPUR says:

ii)
You need one software license for each physical processor on a server, which permits you to run on that server, at any one time:

  • one instance of the server software in one physical operating system environment (or OSE) , and
  • four instances of the server software in virtual operating system environments (or OSEs).  You may run only one instance per virtual operating system
    environment (or OSE). You may run an instance of Standard in place of Enterprise in any of these virtual operating system environments (or OSEs).

But the SPUR also says:

i)     For each additional set of up to four instances of the server software that you run in virtual operating system environments (or OSEs), you need an additional software license for each physical processor on the server.

Roughly translated this means:

  • On a server with a single CPU, one EE processor license allows 4 VMs (no vCPU count needed). On a server with 2 CPUs, two EE processor licenses allow 4 VMs (no vCPU  count needed)
  • On a server with a single CPU, two EE processor licenses allow 8 VMs (no vCPU count needed). On a server with 2 CPUs four EE processor licenses allow 8 VMs (no vCPU count needed)

Note: Twisted thinking is required here. The number of allowed VMs (4) is not related to the number of processor licenses, which is why two CPUs do not amount to 8 VMs. The number of allowed VMs (4) is assigned to all the physical CPUs (licensed per proc) considered as the licensed server. To raise the VM allowance to 8 it’s necessary to double the license count per CPU. Best advice: in virtualized scenarios avoid Standard Edition, and only use Enterprise Edition when the case clearly warrants it.  For most virtualization scenarios use Datacenter Edition (see below)

Exceptions & qualifications to the above for Datacenter Edition:

License all physical CPUs on the virtualization host and run any number of Windows Server Editions (Standard, Enterprise, Datacenter, Web) in virtual machines.

The SPUR says:

Windows Server 2008 R2 Datacenter and Windows Server 2008 R2 for Itanium Based Systems. You need one software license for each physical processor on a server, which permits you to run on that server, at any one time

  1. one instance of the server software in one physical operating system environment (or OSE), and
  2. any number of instances of the server software in virtual operating system environments (or OSEs) (only one instance per virtual operating system environment (or OSE)).

You may run on the licensed server an instance of Web, Standard or Enterprise in place of Datacenter in any operating system environment (or OSE).

At least this is simple and clear and is a major reason to use Datacenter in most SPLA virtualization scenarios.

Note: Unlike the specific rule in Volume Licensing, which says that Datacenter can only be licensed on servers with a minimum of two processors, Datacenter under SPLA can be licensed on a single processor (multicore) server. One CPU license allows unlimited VMs running any Windows Server Edition (hardware permitting).

Note: Running VMWARE ESX or vSphere on the virtualization host makes no difference to the Microsoft license requirement for Windows Server. Whether or not Hyper-V is running as the hypervisor, both host and VMs will need to be licensed under the rules above (unless of course only Linux is running in VMs )

9 Comments

  1. Can you not license extra VMs seperately? i.e. 5 VMs on a single core EE requires 1 EE CPU and 1 of whatever the VMs are.

    I’m confused about the last paragraph, where you mention where the host will need to be licensed even if you’re using VMWare etc.

    What if you’re using Hyper-V Server as the hypervisor? Surely in that case, you just license as follows: for physical CPUs with dual core processors, a VM with 1 or 2 cores requires 1 CPU license, 3 or 4 cores to a VM requires 2 CPU licenses. Physical CPUs with 4 or more cores mean that each VM requires just one CPU license, given that a VM can’t have more than 4 cores in Hyper-V – until Server 8 comes along that is. If that’s the case with Hyper-V Server, why would any other hypervisor be different?

    • Fair point. The Microsoft SPLA licensing rules for Windows Server apply irrespective of the virtualization technology. How they apply may depend, as you point out, on the way that vCPUs are assigned/derived from physical CPUs. Standard Edition requires you to count the physical CPUs AND the vCPUs. Your core to vCPU assignments & calculations are further reasons NOT to use Standard Edition, I would say!

  2. Your comment is that “At least this is simple and clear and is a major reason to use Datacenter in most SPLA virtualization scenarios.”

    But..does the SPUR not state that you can’t realyl use it for anything except anonymous hosting (like a public website?)

    DC is for anonymous use only. You cannot use this server as a platform for applications such as MS
    Exchange Server, Windows SharePoint, Office SharePoint, or any third party applications that have
    direct or indirect interaction with Windows authenticated services.
    Why license Data Center?
    DC is typically a backend server.
    For example, if you are running a static website with Web Server (front
    end server) you can license DC as a backend server with SQL. This server also allows unlimited virtual
    instances.

  3. I don’t know which SPUR you’re reading but the anonymous use case was removed in about July 2009. Outsourcer/non-outsourcer license was introduced at that time to replace the authenticated/non-authenticated distinction. Now even that is gone, leaving Datacenter as the license of choice for most SPLA scenarios.

  4. I was apparently reading something outdated for sure…went back through the latest and tried to find the working from HP (spla provider) and what they told me was actually incorrect…

    my life just got much easier…

  5. Am I right in understanding (or assuming!) that under SPLA I can install Hyper-V Server 2008 R2 (which is a free download and of course does not contain any guest VM licenses) but report a Datacenter host to MS and be all set?

    You already said that this applies to VMWare or any other virtualization host (and also Mark’s comments are asking something like it for Std Ed) but I’d like a confirmation.

    Thank you in advance and thanks for the very informative article!

  6. Yes you are right, but there are things that are hard to do in the CLI that can easily be done using the GUI. If you’re paying for it anyway, why not use it?

  7. I guess the only reason would be the reduced attack surface, the less number of necessary Windows Updates and the lighter resource usage for the host. Of course these are claimed by Microsoft, I haven’t really tried it.

    And since Hyper-V is managed anyway by SCVMM, if you can get it up to that stage (set up and talking with SCVMM) then why not? 🙂

    Then again Windows Server 2012 is right around the corner (September 4th) so everything changes again. Actually, I can’t wait for it! 🙂

    • It’s true that Microsoft recommend Server Core as a best practice though I wonder how many adhere to this. The advantages of Server Core installations are theoretical at best when you consider that although patching may be reduced it will still probably require one reboot a month in any case. Reducing the attack surface sounds good but is hardly likely to be an issue for virtualization hosts which shouldn’t in any case be connected to the Internet. Even hardened PowerShell users will admit that some tasks are much easier to do in the GUI. Why not use it if you’re paying for it anyway? Hyper-V Server doesn’t save on cost, and doesn’t improve on productivity so why use it in production environments?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: