The feature-rich server operating system Windows Server is now an integral part of the IT infrastructure of most businesses and organizations. It should be seen primarily as a mediator between hardware, software, and the user. With the help of the server operating system, files and services can be shared and directories and users can be managed according to the most diverse requirements. However, Windows Server licensing regularly raises many questions, especially for startups and young businesses. With this blog post we bring the most important information about license types clearly to the point.
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How to license Windows Server Essentials?
The correct Windows Server license depends largely on the edition you choose. In addition to the Essentials edition, a Standard edition and a Datacenter edition are available.
Windows Server Essentials is intended for companies with up to 25 employees and can only be installed on one server per organization. This restriction is due to the fact that each Essentials server must be a domain controller at the same time. The use of the server operating system is restricted to servers with a maximum of two CPUs. However, separate access licenses, which are called CALs (Client Access Licenses), are not required for this. Employees can use Windows server features with up to 50 devices.
Basic licenses for Windows Server Standard and Datacenter
Since Windows Server 2016, Microsoft has relied on so-called basic licenses in relation to access licenses for standard and data center editions. There are some details to consider here.
In principle, each processor core of the running hardware must be licensed. For example, as soon as the software runs on a server with 16 processor cores, at least 16 cores must be licensed.
Another requirement is that at least 8 cores per processor must be licensed. For example, if you use hardware with 4 processors, each with 4 cores, you must license a total of 32 cores (4 processors x 8 “minimum core license package”).
When looking at the server as a whole, there is also a minimum license to consider: 16 processor cores per server must be licensed, even if using hardware with fewer cores.
When purchasing a Windows Server Standard or Datacenter product key, you can choose between a 16-core and a 24-core version. The core licenses purchased with the server software represent a base that can be expanded at any time with separate 2-core, 4-core, and 16-core license packs. Consequently, additional or new hardware can be licensed without any problem.
One last special feature to note with Windows Server Standard: A maximum of two virtual machines or OSE/Hyper-V containers can be run on a licensed Standard server. As soon as more virtual environments are required, a full license renewal will be required. While a maximum of 2 Windows servers can be run on a licensed 16-core server, running 3 Windows servers requires 32 cores. No additional licenses are required for Linux instances.
Access licenses for Windows Server Standard and Datacenter
Access devices and users must be equipped with separate access licenses for Windows Server Standard and Windows Server Datacenter. While a User CAL allows a specific user access to all of the company’s Windows servers, a Device CAL is used to authorize a specific end device.
Users with a User CAL can use Windows server features with any device. Rather, multiple different users can use a licensed end device to access the server.
When purchasing a newer version of the server operating system, such as Windows Server 2019 Standard, the previous access licenses can no longer be used. However, servers running Windows Server 2016 Standard can be accessed, for example, with 2019 CALs.