Server Core

Honey, I shrunk the server! Another chapter, another outdated movie reference. Over the past 20 years or so, we have seen nothing but growth from Microsoft operating systems. Growth can be good; new features and enhancements make our lives easier. But growth can also be bad, such as bloated file structures and memory-hogging graphical interfaces. If you were to chronologically graph the Windows and Windows Server operating systems in terms of their footprints based on factors such as disk space consumption and memory requirements, it would show a steady upward slope. Every new release requires just a little more processing power and just a little more hard drive space than the previous version. That was the case until, I'm guesstimating a little bit here, maybe Windows 8 and Server 2012. We saw some surprising steps taken with lowering these threshold numbers, a welcome change, but the change wasn't too dramatic. I mean, what can you glean from the fact that...

Why use Server Core?

Why am I even talking about Server Core? Hasn't it been around since 2008? Yes, that is exactly why I am talking about it. The Server Core variant of the Windows Server operating system has been around for quite some time, but it seems like many admins are scared to trust it. I work with many different companies from many different industries. They all have one big thing in common: they use a lot of Windows Servers, and all of these Windows Servers are running the full GUI (Desktop Experience). Have they heard of Server Core? Sure. Have they tested it out in a lab? Sometimes. Everyone seems to have a slightly different experience level with Core, but it's quite rare to find one in production. Maybe I'm just talking to the wrong people, but I have to assume that there is a majority of us out there, myself included, who need to start using Server Core on a more regular basis.

Why do we need to start using Server Core? Because GUI-less servers...

Interfacing with Server Core

After running through your first installation of Server Core, you will be presented with the following lock screen:

Figure 10.3: Server Core lock screen

Is that really a Command Prompt window that says Press Ctrl-Alt-Del to unlock? Yes, yes it is. This usually gets a few chuckles when an admin sees it for the first time. I know it did for me, anyway. It reminded me a little of when we used to code if/then games on our TI-83 calculators during high school math class. Press Ctrl + Alt + Del, and you will be prompted to change your administrator password for the first time, which is the same task that must always be performed first inside GUI versions of Windows Server. Except, of course, that you do it all from within the Command Prompt window using only your keyboard. Once you are officially logged in to the server, you will find yourself sitting at a traditional C:\Windows\system32\cmd.exe prompt, with a flashing cursor awaiting instructions...

Windows Admin Center for managing Server Core

While Command Prompt from the console, remote PowerShell connections, remote Server Manager administration, and even the RSAT tools running on a Windows 10 workstation are all valid and powerful tools for administering our Server Core instances, they have all now been upstaged by the release of Windows Admin Center. You have already learned what Windows Admin Center can do for centrally managing your entire server infrastructure, but what we need to point out here is that WAC can be used for servers both with and without graphical interfaces.

I have spoken with many Windows Server administrators about the topic of Server Core, and one of the biggest blocks to implementing these more efficient and secure server platforms is an apprehension that, once configured, ongoing administration and maintenance of these servers will be more difficult to handle. Admins who are familiar and comfortable working within the Windows Server Desktop Experience...

The Sconfig utility

Now we will take a step backward and check out a tool that is available inside Server Core, but one that is generally only useful when working on the console of your server. As you have seen, any time that you boot Server Core, you land inside a Command Prompt window from which you can flip over into PowerShell and then use traditional Windows cmdlets to configure your new Server Core instance.

Alternatively, you may employ the Sconfig utility. This is a set of tools, kind of like command-line shortcuts, for implementing the basic items needed to bring your new server online and get it connected to the network. The purpose of Sconfig is to be step 1 after installing the operating system, taking care of the initial configurations on the new server so that you can then jump over to using one of the more robust administrative interfaces, such as Server Manager or Windows Admin Center.

Immediately after spinning up a Server Core instance, you find yourself...

Roles available in Server Core

Server Core is obviously a restricted form of the operating system, and some of the roles inside Windows Server are just not designed to work properly within that limited context. Fortunately for us, most of them are, which enables Server 2019 administrators to deploy most of their critical infrastructure via the more secure Server Core platform. Here is a list of the roles that are currently supported to run on a Windows Server 2019 Server Core instance, and I marked the ones in bold that I see most often used within the businesses I work with:

• Active Directory Certificate Services
• Active Directory Domain Services
• Active Directory Federation Services
• Active Directory Lightweight Directory Services
• Active Directory Rights Management Services
• Device Health Attestation
• DHCP Server
• DNS Server
• File and Storage Services
• Host Guardian Service
• Hyper-V
• Print and Document Services
...

Building a Server Core domain controller

You are now equipped to spin up Server Core instances, configure them with hostnames, IP addresses, and domain memberships, and administer these new servers using various administrative toolsets. One of the most frequent uses of Server Core that I have seen in production environments is as a secondary domain controller. Let's walk through the process of setting one up so that you have exact steps if ever this situation applies to you.

Begin by prepping the new server. You already know all of this, but here is the basic outline of steps that you want to accomplish before thinking about turning this server into a domain controller:

1. Spin up the new server and install Server Core.
2. Use Sconfig or PowerShell from the console to configure a static IP address and a permanent hostname. Remember, once you turn this server into a domain controller, it is not supported to change the name, and not easy to change the IP –...

What happened to Nano Server?

This story about small-footprint Windows Server platforms didn't used to end with Server Core. Anyone who kept tabs on the new features coming out with Server 2016 is aware that there was another installation option for the Server 2016 operating system, called Nano Server. The premise of Nano Server was an even smaller, more secure, more efficient, super-tiny operating system that could run a limited set of roles. Though limited, it was still capable of being installed on a physical or virtual server platform, run as a true server operating system, and could still host traditional workloads on it.

Unfortunately for Nano Server enthusiasts, and especially for anyone who has already done the work of installing and using it, the story behind Nano Server has flipped around completely over the last few years. To cut a long story short, you can no longer use Nano Server for anything that a traditional server can do. You cannot install it on physical...

Summary

I have to be honest with you—writing this chapter has been exactly the kick in the pants that I needed to start thinking about shrinking my own servers. I am in the same boat as many of you: I know what Server Core is and have played around with it but have never taken the steps to really use it in the production environments that I support. Now that tools such as Sconfig and the new Windows Admin Center are available to us, I have officially run out of excuses as to why I shouldn't be deploying new roles onto Server Core boxes. In fact, as I was building out the new DC3 server, I realized just how much faster it is to get a Server Core instance off the ground compared to the full graphical interface. Reboots are faster and using Sconfig to set the IP address, hostname, and domain membership all took me about 2 minutes in total.

While it never hurts to learn something new, using Server Core no longer comes with the requirement that you must be fluent in PowerShell...

Questions

1. True or False—Server Core is the default installation option for Windows Server 2019.
2. True or False—You can utilize PowerShell to change a Server 2019 from Server Core mode to Desktop Experience mode.
3. When sitting at the console of a freshly booted Windows Server 2019 Server Core instance, what application do you see on the screen?
4. What cmdlet can be used to view the current networking configuration on a Server Core?
5. Which PowerShell cmdlet can be used to configure the hostname of a Server Core?
6. Name some of the management tools that can be used to remotely interface with a Server Core.
7. What is the name of the utility built into Server Core that can be launched to provide quick task links for configuring IP addresses, hostnames, and domain membership?