The release of the most recent version of Windows Server 2016 may offer a few surprises to several of you. First of all, the updated OS version comes in a Core edition only, both for Standard and Datacenter editions. Secondly, the update schedule follows a different pattern, compared to the mainstream version of Windows Server 2016 RTM, that came out in September 2016. Thirdly, not all roles that are part of Windows Server 2016 are available in the 1709 release.
So let’s take a look at the first one. Core is now used by default and no GUI version is available in this specific release. However, we expect the GUI to come back in upcoming versions. Why Core only you might ask? It’s because the primary goal for this new server release was to be the perfect container host. Because Microsoft included the Windows Subsystem for Linux (WSL), version 1709 now both supports Windows and Linux containers.
WSL is a collection of components that enables native Linux ELF64 binaries to run on Windows. It contains both user mode and kernel mode components. It is primarily comprised of: User mode session manager service that handles the Linux instance life cycle.
Apart from being a superb container host, Windows Server version 1709 is also perfectly suitable as a container OS itself. Notably if Nano Server is used as a container OS, the default Nano Server container size has been reduced by nearly 80%: from 390 MB to 80 MB. This enables developers to take advantage of a much smaller image which is ideal for building new applications or adding new services to existing applications.
The second remarkable observation focuses on the new release schedule. When Windows Server 2016 came out, it followed the standard Long Term Servicing Branch (LTSB) which offers a new version every 2 to 3 years with a 5-year mainstream support and 5-year extended support. At RTM time, Microsoft already placed Nano Server into the Current Branch for Business Only (CBB), which would offer updates at a more rapid “cloud like” update pace. With Windows Server 2016 release 1709, now Core has come to the Semi-annual Channel (SAC). As you can see below now both Nano Server and Core are part of SAC, with 2 to 3 updates per year. For Nano Server, and now perhaps also for Core, customers will have to keep up-to-date and cannot stay behind more than 2 releases.
The third notable thing, is the omission of Storage Spaces Direct (S2D), the software defined storage solution offered since Windows Server 2016 RTM. Although it was originally planned to be part of 1709, it was taken out temporarily as it simply was not ready yet and could not yet measure against Microsoft’s quality standards. Because S2D can be considered a mission critical piece of technology, any serious flaw in this enterprise storage solution would fire back on Microsoft. Because 1709 focuses on containers, it was decided to leave S2D out and bring it back in a future release. We cannot be sure it will be the SAC update in April 2018 or for the next major LTSB release in 2018/2019. Mind you, this by no means implies that S2D is dead. On the contrary, S2D remains a major enterprise technology that offers fundamental storage functionality in Microsoft Azure Stack and in aggregated (hyper-converged) and disaggregated Hyper-V clusters.
All we need is a little more patience before the new updated version of Storage Spaces Direct becomes generally available. If you can’t wait to see its progress, become a Windows Server 2016 Insider and download the latest version.
For more background on the release of Windows Server 2016 version 1709, take a look at this Microsoft Mechanics recording by Jeff Woolsey and Matt McSpirit.