Windows Server has now moved to a licensing structure based on the number of physical cores rather than the number of processors it will run on, in a fashion similar to that already adopted for SQL Server. However, unlike SQL Server where client access is included as part of the cost of core licensing, Windows Server keeps its legacy roots which means that you still need Client Access Licences (CALs) as well. As with SQL Server, Windows Server 2017 is licensed in twin-core packs, but with a minimum of eight cores which requires you to purchase at least four packs.
The virtualisation rights associated with each edition remain unchanged. However, there are a few key points to consider that fall in line with the technology advancements:
- Standard Edition allows you to run up to two Virtual Operating System Environments (VOSEs) or Hyper-V Containers. Multiple licences can be assigned to the same cores for additional virtualisation rights, where required. The Datacenter edition allows for an unlimited amount of VOSEs and Hyper-V Containers.
- Hyper-Threading is no longer accounted for in Windows Server 2017, so you only need to cover the physical cores and can ignore virtual cores.
- If a processor is disabled for use by Windows, the cores on that processor do not need to be licensed. Disabling hyper-threading or core-utilisation for specific applications does not change your licensing obligations.
- External Connectors are still licensed per-server and should be applied to each server that is being accessed, regardless of the number of users or devices.
- Nano Server is a deployment option within Windows Server 2017. It is included as part of the edition that is deployed and is not licensed uniquely or separately.
- 'Nesting' of VMs (the running of one Virtual Machine inside another) is considered separately and so is licensed according to the number of VMs utilised in the scenario. In other words, embedding one VM inside another counts as a Primary plus a Secondary Embedded. In such scenarios the Datacenter edition would work better as it has no cap on virtualisation rights.
- CAL requirements remain unchanged, so every user or device that directly or in-directly authenticates with the Server instance will need to be licensed accordingly.