Questions about Hyper-V 2012R2 licensing compared to 2008 / 2008R2 licensing

First the obligatory, but all important disclaimer: You really should call Microsoft. There are plenty of people out in the world who can give bad advice and "I thought I was legal because someone on Experts Exchange told me" isn't going to be any legal cover. It can cost you *big time* if you screw up.

Now with that said, you need to understand that there is a distinction between a license and an operating system environment (OSE.)  Windows licenses are always "assigned" to a machine. OSEs are the actively running operating systems, either on bare metal or in a VM. There is no such thing as a "guest" license

So for your first question, you are correct. To run 8 VMs on a single node, that node would need 4 licenses. If you wanted three nodes with 8 VMs each, you'd need 12 licenses. And you wouldn't be able to readily move around VMs because the moment you moved a VM to another node, it'd have 9 VMs, which exceeds the 8 allowed by the three licenses assigned to that physical machine.

The rules in 2008 R2 are the same. Only the number of VMs allowed changes. So each physical machine must have its own licenses assigned, and you must have the number of licenses required to cover the number of VMs on that host. So 8 VMs on a node would require 2 enterprise licenses (4 VMs per license for a total of 8) and for 3 nodes, 8 VMs each, that'd be 6 total licenses, 2 per node. And again, you wouldn't be able to readily move around VMs because you've maxed out your VM count allowed per license.

As for your final question, yes. Since licenses are assigned to a machine, it'd cover 2 2012 R2 VMs, regardless of the hypervisor used. They could be running on an older version of Hyper-v (although for technical compatibility reasons, I'd never recommend it), or virtualbox, or VMWare ESX, or other. The license simply permits two virtual OSEs on that physical machine.

This is where buying Datacenter with its unlimited VMs makes more sense. You can shuffle VMs without worrying about your VM count.

Hi Cliff,

Thanks for your reply.

The thing that is not clear to me is do all Hyper-V hosts need licenses to run all Hyper-V VM's available? So if a company owns 2 2012R2 Hyper-V host servers all with 2 CPU sockets, the host server OSE is licenced with 1 2012R2 Std OLP licence, HostSVR1 and HostSVR2. The company is running totally 12 VM's, SVR1, SVR2.... SVR12. They acquire 5 2012R2 Std OLP licences to run these 12 VM's. They are allowed to run these 12 hosts on any of these 2 Hyper-V hosts, 6 on HostSVR1 and 6 on HostSVR2, or 10 on HostSVR1 and 2 on HostSVR2. Or does the company need to acquire 10 2012R2 Std OLP licences to run these 12 VM's, 5 for HostSVR1 and 5 for HostSVR2, every host server needing their own 5 2012R2 Std OLP licences for these VM's?

If a HostSVR3 is added (2 socket CPU, licenced OSE with 1 2012R2 Std OLP licence) to run as replica host, does this HostSVR3 need an additional of 5 2012R2 Std OLP licences to be able to run these 12 VM's, SVR1, SVR2.... SVR12, when HostSVR1 and HostSVR2 are down?

So to be compliant in this case it doesn't require four licenses, two for Server A and two for Server B, because VM1, VM2, VM3 and VM4 can all end up running on Server A or on Server B. Three licenses are enough, because when moving back VM3 form server A back to server B, the extra required license that was needed for running VM1, VM2 and VM3 on Server A becomes available again?

I've been in contact with a certified reseller for advise.
Without Software Assurance indeed four licenses seem to be needed. Both Servers need to be licensed for running all four VM's.
Without SA moving without license is only allowed once every 90 days.