What Is Windows Nano Server, and What Are Its Applications?

Windows Nano Server is a lightweight, 64-bit server OS that is deployed via containers. Released as an additional installation option in the Standard and Datacenter editions of Windows Server 2016, Nano Server is a lighter and faster, more stable and secure, and less resource-intensive alternative to a full-blown Windows Server installation. It is meant to streamline DevOps and is ideal for use in private clouds and datacenters.

What is Windows Nano Server?

Windows Nano Server Prior to Nano Server, the typical Windows server installation was a complex process, involving frequent updates that impacted server performance and left the server open to potential security vulnerabilities. Organizations also did not have any choice but to go the full server route every time, regardless of their requirements.

Microsoft’s release of Server Core mode in Windows Server 2016 aimed to change all that for organizations not needing the capabilities of a full Windows Server. However, Server Core was still too heavy for cloud-based applications. Microsoft came out with Nano Server to address this issue.

Nano Server supports multiple programming languages and runtimes, including .NET, Java, Python and Node.JS. It is optimized for applications built using the above-mentioned languages and designed to run in containers and virtual machines (VMs).

Nano Server contains just a few components, meaning that it is easier to manage and more secure than a typical Windows Server installation. The transition of Nano Server to a container base image in Windows Server, Version 1803, which was released in 2018, makes it even more secure and manageable. This means that Nano Server cannot run as a stand-alone server; instead, you need to run it as a container from within another host. For example, you can run Nano Server in a Windows Server on Server Code mode.

What Are the Benefits of Windows Nano Server?

Microsoft envisioned Nano Server as playing a key role in cloud platforms, specifically eyeing it for Hyper-V compute clusters and Scale-Out File Server storage clusters. Nano Server can also be used as a host server for cloud-based applications and VMs, as a server running Internet Information Services (IIS) or some other Windows-supported web server, or as a domain name system (DNS) server.

The benefits of using Nano Server include:

Less updates and reboots: With its pared-down services, you do not need to apply patches and reboot your server frequently. You cannot say the same for a full Windows Server or even a server hosted on Microsoft Azure unless you risk not applying updates and leave your server open to malware exploits that could impact your operations severely.
Smaller server images: Nano Server is available as a container base image for use in another container host. The size of this image is far smaller than the typical Windows Server installation image. Larger server image sizes are not problematic until you need to transfer or store the images for backup or some other purpose. Not only will backups take time, but you can also run out of disk space quickly.
More disk space available for other purposes: With the disk space you save using Nano Server, you have more flexibility in your operations. For example, you can run more frequent backups and have more space to store important data.
Improved security: There are fewer vectors for malicious actors to exploit due to the stripped-down capabilities of the Nano Server. The lack of a local logon capability or graphical user interface (GUI) adds to its more secure posture.
Better performance: A smaller server with fewer running resources means less memory consumption. This leads to a smoother-running and more efficient server that is less prone to breakdowns.

Although Nano Server could not handle all the use cases associated with Windows Server, it is a competent and reliable server OS for cloud-based datacenters. If your organization relies upon and uses VMs and containers running on Windows Servers already, Nano Server is a suitable alternative to another full Windows Server installation.

What Are the Differences Between Windows Nano Server and Either Server Core or Server with Desktop Experience?

Nano Server is essentially a stripped-down version of the full Windows Server OS, as it is headless—it does not have a GUI—and lacks the core server components. It is like the Server Code mode in Windows Server but is even more bare-bones than the former, requiring minimal disk space and supporting only 64-bit applications, drivers and services. As it is meant to deliver applications via the cloud, the Microsoft Windows Installer (MSI) application installation and configuration service are also not present in Nano Server.

As a Hyper-V host, Nano Server uses key management service to activate its guest VMs. Nano Server support is more active, with update releases expected at least two or three times yearly. Nano Server installations must not be more than two releases behind, and administrators must update servers manually to keep them current.

Compared to Server Core or Server with Desktop Experience, Nano Server cannot act as a domain controller for your Active Directory and as a proxy server. It also does not support:

Group Policy.
Load balancing and failover.
Microsoft Endpoint Configuration Manager and System Center Data Protection Manager.
Best Practices Analyzer (BPA) cmdlets and BPA integration with Server Manager.
Virtual host bus adapters (HBAs).
How Has the Role of Windows Nano Server Changed over Time?

If you installed Nano Server during its initial release back in 2016, you would only need to configure it post-installation using scripts created in Windows Management Instrumentation (WMI) and PowerShell. Starting with Windows Server, version 1803, released in 2018, Microsoft transitioned Nano Server into a container base image that is even smaller than the original Windows Server 2016 version. To use Nano Server, you now need to run it as a container on another host, such as a Windows Server running on Server Core mode. This is like nesting the server within another server.

Other recent changes in Nano Server are in line with Microsoft’s thrust towards using it for cloud deployments. These include:

Optimization for .NET Core applications.
Non-inclusion of PowerShell Core, .NET Core, and WMI in the container base image, though you can add these packages when building your container.
Availability of the updated Nano container in Docker Hub for redeployment purposes.
Use of Docker for troubleshooting the container.
Support of Nano containers for the Windows IoT Core.

Parallels RAS and Nested Virtualization

Parallels® Remote Application Server (RAS) provides streamlined and secure access to virtual desktops and applications from any device anywhere and at any time. Parallels RAS supports sophisticated setups in Windows Server environments, including the use of Nano Server as a container in another Windows Server. Using Parallels Desktop and its nested virtualization support, you can nest a Hyper-V VM inside other Windows Server VMs within your infrastructure.

Parallels RAS allows the quick and easy setup of a virtual desktop infrastructure (VDI) with improved security and centralized desktop management capabilities. To see how it can be used in your Windows Server environment, download the Parallels RAS trial today.

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