First look: Windows Server 2016 goes on a cloud diet

Windows Server 2016 is both an evolution of the current Windows Server 2012 R2 release and a revolution in the making. If you plan to use Windows Server 2016 in the same way you’ve used Windows Server all along, you’ll be able to pick it up and work with it with very little learning curve. But if you are ready to abandon the old ways and embrace the new world of cloud servers, containers, and microservices, Windows Server 2016 has something new for you. 

That something new would be the Nano Server install option, which uses a refactored Windows Server to deliver a headless, compact (with a footprint currently around 400MB), remotely managed server. With no local log-on at all, Nano Server is the most extreme encapsulation of Microsoft’s philosophy behind redesigning Windows Server for tomorrow’s data centers. Instead of point and click, the focus is on managing Windows Server through scripts and configuration management tools.

It’s been some time since Microsoft released the first Technical Preview of Windows Server 2016, and this second release has many new features and makeovers, with changes in Active Directory, file and storage services, clustering, networking, and PowerShell. Many of the new features are designed to help build cloudlike data centers and to make Windows Server behave more like Azure.

Good-bye GUI

Running the Windows Server 2016 installer makes it abundantly clear that Microsoft is deprecating the GUI in Window Server, continuing the migration toward the concept of servers as an element in a programmable infrastructure. Installing the full server now defaults to what would have in the past been the GUI-less Server Core. Installing a GUI requires choosing a “with local admin tools” option. You won’t see a Nano Server option in the Window Server installer, as installing Nano Server requires building a custom image and using Windows’ remote installation tools.

I installed Windows Server 2016 in a test Hyper-V VM with the admin tools option. It boots up with a command line (ready to launch PowerShell), along with the familiar Server Manager. You can add a full shell that has most of the familiar Windows 10 user interface elements, including the Start Menu and the new Edge browser, if you want them. Another option gives you the command line only, requiring the use of remote server management tools for more complex tasks. Servers can be centrally managed by PowerShell and group policies, but if you want a GUI to manage a departmental server or a branch office, it can be installed using Windows Server’s Add Roles and Features tooling.

Windows Server 2016’s Hyper-V updates are focused on delivering private clouds -- and on helping you migrate your existing servers to the new version. One big update is support for rolling updates for clustered Windows Server 2012 R2 instances. Each node in a cluster can be upgraded to Windows Server 2016 without affecting the others, and each upgraded node will run as Windows Server 2012 R2 until the last server has been upgraded, at which point all the servers will run as Windows Server 2016.

VM portability is important, and until you explicitly upgrade the configuration files for an upgraded Hyper-V VM, it will continue to run as if it were hosted on Windows Server 2012 R2. You can keep VMs in this state until all your host servers have been upgraded, as it means they can be migrated to and run on older Hyper-V installations. Once all your servers have been upgraded, you can switch the version of your configuration files, giving access to new features -- but removing cross-version portability.

One big new Hyper-V feature hasn’t made it to the current technical preview: support for nested Hyper-V virtual machines. When nested VM support arrives, your Hyper-V host will be able to run a virtual machine that is itself a Hyper-V host, so it's easier to quickly deploy test and development environments.

Hello Nano Server

Nano Server is the biggest new feature in Windows Server 2016. Best thought of as an alternative install option, it’s not a separate SKU. Microsoft describes it as a platform for “born in the cloud” solutions and scale-out microservices. An extreme refactoring of the Windows Server platform, Nano Server rolls in at around a tenth of the size of a full Windows Server 2016 install. As noted above, it is completely headless and has to be managed via remote management tooling, including PowerShell remoting. It’s purely 64-bit, so any 32-bit code you have will need to be completely rewritten.

Currently the process for building and installing Nano Server requires familiarity with DISM, Microsoft’s Deployment Image Servicing and Management tools. A Windows installer image for Nano Server is included in the ISO download, and you can use it as the basis for building a virtual hard disk image that can then be used with Hyper-V. Converting an image into a virtual machine isn’t simple, but you can expect Nano Server deployment tooling to arrive as part of System Center 2016.

Once Nano Server is deployed and installed, you’ll need PowerShell’s remote management tools to work with it. Using DISM to quickly deploy and configure new Nano Server virtual hard disks makes a lot of sense, as it’s intended for cloud-based, scale-out systems, where servers will need to be deployed and configured on the fly as needed. Once you’ve made the initial DISM image, remote management tooling can apply server configuration as the image is deployed.

A typical use case for Nano Server is as a guest OS in a Hyper-V cluster, with each instance hosting a service. As services scale, new copies can be instantiated and run as required (Microsoft demonstrated a single server running more than 3,000 instances at its recent Ignite 2016 event in Chicago). While you can install extra roles and features on Nano Server via PowerShell and use DISM to add them to the initial install image or VHD, you’re initially limited to a small subset of server roles, including compute, fail-over clustering, and file server roles. Don’t expect to run VDI or graphical management tools on Nano Server -- there is no graphics stack and no way of installing one.

PowerShell power

With PowerShell at the heart of much of Windows Server 2016, a new version adds new features that make it easier to write complex scripts. PowerShell 5.0 adds support for classes, as well as for working with information streams. The latter can be used to deliver information from scripts to calling functions, giving you the ability to construct management workflows in PowerShell. There are also tools for handling encrypted messages, important for working with servers running in the public cloud or for managing infrastructure over the public Internet.

Similarly, updates to the PowerShell-based Desired State Configuration (DSC) tooling make it easier to manage configurations centrally and to configure servers on the fly as they’re deployed. One interesting combination, DSC and Nano Server, simplifies the deployment of applications and services on newly deployed server images. If you’re using Nano Server to host microservices, DSC will ensure the appropriate prerequisites are in place before you install service components.

Finally, Microsoft has bundled its antimalware tools in Windows Server 2016. While they’re running (and kept up to date) as soon as you boot for the first time, there’s no UI installed by default.

Microsoft’s focus on delivering a hybrid cloud platform is clearly dictating the direction it’s taking in Windows Server 2016. Improvements to Hyper-V mean it’s easier to host and manage virtual machines as you upgrade your host environment, while PowerShell takes center stage with the arrival of the headless Nano Server option. With Windows Server 2016, you get the tools and services you need to build a cloud infrastructure -- ready to overlay the new Azure Stack tools and run a self-service high-density cloud in your own data center. There’s a lot in this new build -- but there’s a lot still to come. As well as some Hyper-V features, the second Technical Preview doesn’t yet handle Windows’ much anticipated Docker-based containers.

This isn’t yet production-ready code, and with key features yet to make their way into a public build, we’re clearly some way from a final release. Microsoft has decoupled server and client development, and Windows Server 2016 isn’t being built with same urgency as Windows 10. Even so, we expect to see progress speed up -- developers, administrators, and operations teams need to get hands-on time with planned features and services before they start thinking about deploying a new Windows Server.