Hyper-V Guest Licensing (including Hyper-V R2)

Some people are still confused with how Hyper-V Guest Licensing works.  This also goes for Hyper-V R2 which hasn't changed *at all* as far as how it can be licensed goes.  So here's a first post on this topic.  If there's more clarification needed, I'll likely post again with all of the questions covered that may arise from this post:

Hyper-V Guest Licensing really isn't in any state of flux - nothing's changed since it was first spoken about. (Well, the price changed, but that's irrelevant to Licensing concerns.)

Now, there's three ways to obtain Hyper-V and Hyper-V R2 and these will change the answer to your question:

1. Hyper-V Server 2008 R2 is a stand-alone hypervisor that is available for free. It is very much like ESXi in that it installs directly onto hardware (let's ignore the embedded ESXi variants for now). It is licensed for installation onto any compatible hardware, basically, and doesn't need any other OS License with it. Any and all OSes you wish to install on top of Hyper-V Server require their own licenses, whatever they may be.

2. Install Windows Server 2008 Standard (or better) x64 Core (or GUI) and then install the Hyper-V role onto this OS. If done this way, the Hyper-V role comes as part of a Licensed Microsoft Windows Server operating system. There are 3 main variants on this theme:

    2.1 Windows Server 2008 R2 Standard - One Physical and up to One Virtual License

        2.1.1 If the Host WS2K8 R2 Std OS that the Hyper-V role is installed on (W2K8 R2 Std Physical License) performs additional functions such as RODC, AD, DHC, DNS and/or other non-virtualization roles, then the License for WS2K8 R2 Std is completely in use and any guests need to be licensed separately.

        2.1.2 If the Host WS2K8 R2 Std OS that the Hyper-V role is installed on (W2K8 R2 Std Physical License) performs no additional non-virtualization-related roles, then the WS2K8 R2 Std Physical License has been used *only* to provide a host environment, so the single WS2K8 R2 Virtual License can be used for any roles you so choose (except, obviously, Hyper-V). Any additional guests need to be licensed separately.

    2.2 Windows Server 2008 R2 Enterprise - One Physical and up to 4 Virtual Licenses

        2.2.1 If the Host WS2K8 R2 Ent OS that the Hyper-V role is installed on (W2K8 R2 Ent Physical License) performs additional functions such as RODC, AD, DHC, DNS and/or other non-virtualization roles, then the Physical License for WS2K8 R2 Ent is completely in use and there are only 3 of the 4 WS2K8 R2 Ent Virtual Licenses available for use. Any additional guests need to be licensed separately.

        2.2.2 If the Host WS2K8 R2 Ent OS that the Hyper-V role is installed on (W2K8 R2 Ent Physical License) performs no additional non-virtualization-related roles, then the WS2K8 R2 Ent Physical License has been used *only* to provide a host environment, so the 4 WS2K8 R2 Ent Virtual Licenses can be used for any roles you so choose (except, obviously, Hyper-V). Any additional guests need to be licensed separately.

    2.3 Windows Server R2 2008 DataCenter - One Physical and unlimited Virtual Licenses

        2.3.1 Regardless of whether the Host WS2K8 R2 DataCenter OS that the Hyper-V role is installed on (W2K8 R2 DC Physical License) performs additional functions such as RODC, AD, DHC, DNS and/or other non-virtualization roles or not, then the unlimited WS2K8 R2 DC Virtual Licenses can be used for any roles you so choose (except, obviously, Hyper-V). Any additional guests need to be licensed separately - such as SBS 2008 and/or EBS 2008 or RedHat Enterprise.

3. If you buy SBS 2003 Premium Edition or EBS 2008 Premium Edition you are supplied a Primary OS (SBS/EBS) and an additional Server + SQL License (and in EBS you also have the Management instance and the Messaging instance).  This Primary OS instance cannot be used as a Hyper-V Host and this is detailed in the EULA.  The additional Server License that comes with Premium can (as in can) be used as both a Hyper-V Host and Guest.  So, in these environments, and we'll stick with SBS here for ease of describing how this would work, here's your options:

    3.1 SBS 2008 Standard Edition

        3.1.1 Install SBS 2008 Standard on Physical - no Hyper-V in use, so we don't care about its Licensing  :)

        3.1.2 Install Hyper-V R2 Server (as mentioned above in Point 1.) and run SBS 2008 Standard as a virtual guest using the SBS 2008 Standard License.

        3.1.3 Purchase an additional Windows Server 2008 R2 (or WS2K8) License and use that as the Hyper-V Host, then install SBS 2008 Std as a virtual guest using the SBS 2008 Standard License.

    3.2 SBS 2008 Premium Edition

        3.2.1 Install SBS 2008 PE Primary Server instance in hardware on one machine and the Secondary Server Instance in hardware on a second machine - we're not using Hyper-V, so we don't care about its Licensing

        3.2.2 Install Secondary Server Instance as Hyper-V Host and then virtualize both SBS 2008 Primary and Secondary Server Instances.  This is very similar to 2.1.2 above - the Secondary Server Instance is providing only virtualization-related services, so it can be used as a licensed virtual guest, in addition to this the SBS 2008 Primary Server Instance (the bit with SBS, Exchange, CompanyWeb, etc) is also virtualized using its virtual key (included with the OS).

        3.2.3 On a second physical server, install Secondary Server Instance as Hyper-V host providing only virtualization services, then virtualize it as a guest and then run the SBS 2008 Primary Instance on the main server.  The second physical server is properly licensed, however here's the options for the main server:

            3.2.3.1 The SBS 2008 Primary Instance can run on hardware, Hyper-V not in play

            3.2.3.2 Hyper-V R2 Server can be used as the host (see Points 1. and 3.1.2 above) and the SBS 2008 Primary Instance as a licensed virtual guest.

            3.2.3.3 An additional License of WS2K8R2 can be purchased and the SBS 2008 Primary Instance as a licensed virtual guest (see Points 2.1.1 and 3.1.3 above).

Now, the only real clarification to this is that Virtual guests can run the OS as Licensed and any other lower product. So, if you have a WS2K8 R2 Ent License, the WS2K8 R2 Ent guests can be WS2K8 R2 Ent, WS2K8 R2 Std, WS2K8 Ent, WS2K8 Std, WS2K3 Ent, WS2K3 Std and so on. If you have a WS2K8 R2 Std License, you cannot run WS2K8 R2 Ent guests unless they are separately licensed. If you wish to run NOWS SBE, SUSE Linux, Free BSD, SBS 2003 or any other OS then you need to be separately licensed for that OS as applicable.

Regards,

The Outspoken Wookie