Microsoft Nano Server, part of the forthcoming Windows Server 2016 release, is a new type of Windows Server deployment that is designed to provide the smallest footprint possible. Like any new Windows Server feature, administrators must consider whether it is appropriate for the organization, and if so, how to best use it.
Nano Server is similar to Server Core in that it lacks a GUI interface, but beyond that, there are several major differences between the two deployments. Nano Server also lacks the Win32 APIs the graphical environment requires. Many of these APIs still exist in Server Core deployments because they allow command prompt windows and similar items to be displayed. In contrast, Microsoft stripped support for MSI application packages or for 32-bit applications in Nano Server. Nano Server is so lightweight that it does not have a local interface, nor does it support local logins.
A whittled down version of Windows Server
Microsoft made Nano Server so basic, so what can we do with it? After all, stripping away the vast majority of the feature set from Windows Server greatly reduces the server's capabilities.
Microsoft detailed four specific roles for use on Nano Server: DNS, DHCP server, Hyper-V and scale-out file servers. Since Windows Server 2016 is the first version of Windows Server to support the use of Nano Server, it seems likely Microsoft will support a very limited number of roles at first, and then add support for additional uses as Nano Server matures. Microsoft took a similar approach to Azure. For example, Microsoft did not initially support running Exchange Server on Azure virtual machines (VMs), which now it does.
It is easy to take a somewhat cynical view of these limited Nano Server roles. After all, services such as DNS and DHCP are already lightweight and do not generally consume many resources. As such, it's easy to question whether there is any real benefit to move these services off traditional VMs and into Nano Server.
Where Microsoft Nano Server can help
Microsoft said there are three main areas where businesses will benefit from using Nano Server: security, availability and scalability. From a security perspective, Nano Server has an attack surface that is about 93% smaller than a Server Core deployment. Because Microsoft has removed so much of the code, the company estimates there will be about 92% fewer critical security bulletins released for Nano server.
The small code base affects server availability. Because so much of the legacy code is gone, patch management becomes easier and less intrusive. Microsoft estimates there will be 80% fewer reboots required in the patch management process.
Lastly, Microsoft said Nano Server will provide significant scalability. Nano Server has a small footprint, and this, combined with the types of roles Microsoft envisions, means Nano Server should consume fewer system resources. This feature will allow IT to develop higher levels of virtual server density. According to some estimates, a single Hyper-V host may be able to accommodate 1,000 or more virtualized Nano servers.
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