@CESC 

Your MS licensing will be completely agnostic to Nutanix and must be dealt with separately. Even if you’re running a lab with Nutanix CE you may still be required to hold MS licensing for Windows VMs. I highly recommend you talk to your MS licensing VAR to get full clarification and ensure you’re operating within your licensing contracts. 

If you’re using trial / evaluation Windows Server editions then you should be just fine as long as you work withing the time limits those come with. 

If you’re an MSDN license holder then you might be OK if you’re using MSDN keys for your windows installs - there are limitations to how MSDN instances are used so again you’ll need to review with MS or a licensing VAR to ensure compliance. I think that with MSDN - if you build a Windows MSDN VM that any user who uses that VM would need to hold their own MSDN developer license, ie one developer can’t ‘own’ all the Windows server to get them all legit under one license. I might be way off here so you’ll need to verify - I’m not an MSDN license holder though I do morn the loss of the MS TechNet subscription...

If as the previous poster concluded that this is for a production deployment then you’ll be paying MS a ton of cash. They operate on a pay for the parking lot vs pay for one spot in the parking lot - you have to ensure that you have a MS Windows Server Datacenter license for every single physical CPU core in the cluster. You can limit some of your licensing costs by making some clusters “Windows Only” so you’re not running Linux or other workloads on cores licensed for Windows…. Also note that there are restrictions to how frequently you can add or remove Microsoft licensing from a hypervisor host - this seems to remove our ability to dynamically allocate licensing based on loading… crocodiles and sharks lie here, if you have any questions or even remotely think you may not fully understand your licensing for VMs you need to engage your VAR support team to nail that down or you could be in for large fines if you’re ever audited. Same goes for Oracle and other vendors with the ‘pay for the parking lot’ licensing model.

Hope this is of some help.

For Win 2019 Standard;

• All physical cores in the Server must be licensed
• A minimum of 8 cores must be licensed for each processor
• A minimum of 16 cores must be licensed for each Server
•  For every two (2) additional OSEs or Hyper-V Containers, all the cores in the Server must be licensed again.

How many virtual CPU’s does not matter. 

So basically you have to buy 16 core licenses per physical node (if you have 16+ physical cores you need to license above that) just to get 2 vms. 

Because it’s a 6 node cluster you need to license all nodes. 16 cores * 6 nodes = 96 core licenses. That will allow you to run 2 standard VMs that can run on all the machines.

Even if you just want to run 1 VM with 1 virtual cpu and it can be moved across 6 physical nodes you have to license at minimum 96 cores.

Every two VMs have to be licensed for every machine they CAN run on. 

https://virtuallyinclined.com/2019/03/27/windows-server-2019-licensing-calculator/

For what you described, 2 VMs, running on up 6 nodes, assuming 16 cores per node.

• 2-Core Pack License Cost = $ 121.50
• Cores Per Virtual Host = 16
• 2-Core Packs Per Virtual Host = 8
• 2-Core Packs For All Virtual Hosts = 48
• Cost Per Virtual Host = $ 972.00
• Virtual Host Count = 6
• Cost For All Hosts = $ 5,832.00

Yes, $6k to run 2 VMs. 

12x 2019 Stardard VMs would run you about $36k

Unlimited 2019 Datacenter VMs would run you about $37k 

Welcome to Microsoft Licensing.

You see why Datacenter becomes attractive. 

To add to the previous comment, with Windows Server Standard licenses you can only migrate a VM once in a 90-day period meaning that if the AHV load balancing function moves a VM more than once in a 90-day period you are in breach of the Windows Server Standard License.

I currently have an AHV cluster with 3 nodes and all nodes are licensed with Windows Server Datacenter meaning we are not only without the 90-day limit but we also have no limit on the number of VMs we can install per node. The only issue with the Datacenter licensing is that you have to pay the Software Assurance up every two years which costs about 1/3 of the original license cost, but this allows you to upgrade to the next OS the moment it is released.

I believe from a cost point of view the Datacenter licensing starts to become the cheaper option at the point of having 10 VMs per node of which I have 13 per node.