Microsoft announced that Windows Server 2016 will be licenced in a per-core + CAL (client access licence) model. This changes from Windows Server 2012 and 2012 R2 which were per-processor + CAL.
Whilst the main editions of Windows Server 2016 remain Standard and Datacenter (US spelling of course), another change is that Datacenter enjoys more features than Standard. This was not the case with Windows Server 2012 and 2012 R2 when Standard and Datacenter had exactly the same set of technical features and capabilities.
The licensing rules in brief
- All physical cores in the server must be licenced
- Core licences are sold in packs of 2
- A minimum of 8 cores per processor must be licenced, even if the processor has less than 8 cores
- For a single-processor server, a minimum of 16 cores must be licenced
- Only physical cores need be counted; hyper-threading has no effect on licensing
- Processors that are disabled in the server do not need to be licenced
- Licensing all cores in the physical server with Datacenter edition allows you to run Windows Server in an unlimited number of VOSEs (Virtual Operating System Environment) on that server
- Licensing all cores in the physical server with Standard edition allows you to run Windows Server in two VOSEs (Virtual Operating System Environment) on that server. You can apply extra licences to the physical server if you wish to run more than two.
A bit of background
If you’re scratching your head about the minimum licensing requirement or even why Microsoft chose to change the licensing model at all, a little explanation may help.
The reason for requiring a minimum of 16 core licences per server is to keep the prices of Windows Server 2016 in line with the minimum licensing (2 processors) of Windows Server 2012 R2. In turn, Windows 2012 required a minimum of 2 processors because it kept the price in line with the per-server + CAL model from Windows Server 2008 R2.
One reason for changing to per-core model is to align with a new benefit that will soon be in Microsoft Azure which will allow customers who have Software Assurance (SA) on their Windows Server licence to ‘lend’ that licence to the Azure datacentre. So you would only need to rent an empty VM and upload your own Windows image instead of paying for an Azure VM which had Windows. Azure compute units are based on cores so it makes sense for Windows licensing to match.
With Windows Server Datacenter edition, it gets even better because you don’t lose your on-premises rights and you can virtualise on-premises at the same time as on Microsoft Azure. We’ll blog about that in more detail at a later date.
System Center 2016 and Core Infrastructure Suite 2016 (a single SKU combination of both Windows Server and System Center) will also be licensed in the new per-core model.
You can read this Microsoft datasheet for the official line.