Windows

Breaking down the Windows Server 8 Features on Demand option

Installing Windows Server 8 brings options to server administrators. Rickatron highlights the new Features on Demand installation in this blog post.

For the Windows Server 8 Developer Preview, there are three main installation types: Full, Server Core, and Features on Demand. The Features on Demand option is new compared to Windows Server 2008 R2, and is made to provision a complete installation of Windows Server with the option for additional features available for installation remotely.

During an installation, selecting the new Features on Demand option will provide the basic features while additional roles and features can be added from a remote source. This is primarily a disk space-saving technique, and this option is shown in Figure A:

Figure A

Features on Demand as an installation option.

Features on Demand as an installation option.

The key difference with Features on Demand is that all of the capabilities of the server role can be run on this installation, but they don’t take up unnecessary disk space after the system is installed. Further, this will also reduce the surface area for Windows Updates, ongoing. I had a chance to talk to a distinguished engineer from Microsoft, Jeffrey Snover, about this very topic on a podcast, and the logic is that we can reduce the resources on the server yet increase the reliability. Giving this some thought, it makes perfect sense in the virtualized world and resource constrictive parameters that we deal with today.

On a Windows Server 8 system installed with the Features on Demand option, you can easily see how all of the features are removed with the DISM tool. The DISM is a deployment tool that can modify and report on Windows installations. See the following command:

Dism.exe /online /get-features /format:table

Running this on a default installation shows a number of features “Disabled with Payload Removed” listed for each feature, as shown in Figure B:

Figure B

Listed features

Listed features (click to enlarge)

This shows the feature inventory on a system, and in the case of Features on Demand installations, what is not consuming disk space for the features. A Windows Server 8 Core system takes around 5.5GB of disk space, a Features on Demand installation takes around 7.5GB of disk space, and a Full installation takes around 8.9GB of disk space. While a 1.4GB or so savings may not sound like a bunch, it would be significant across hundreds of virtual machines.

Does the Features on Demand installation option appeal to you? Share your comments below.

About

Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.

6 comments
pgit
pgit

This is a great idea... almost.. almost LINUX-LIKE! ;) Seriously, this is one of those "where has this been all these years" kind of features, long needed. I could never figure out why something like this was not an option. Can it be that difficult to implement? BTW if you go to add a feature will it call for the install media (disk) or can it fetch the stuff on line?

blarman
blarman

I guess I'm just still shocked that a server installation STILL needs over 5 GB? Hello? What is in there that you can't strip out? I'll be impressed when you can get the install down to 1-2GB.

blarman
blarman

It used to want the install media. Hope they've fixed that by now, but if someone could confirm it would be nice.

b4real
b4real

It is a pretty big install.

Gisabun
Gisabun

Well, excluding the virualized servers, will a few GB make a huge dent considering the size of disks now installed in servers? 10 years ago may have been an issue, but not as much now.

blarman
blarman

Microsoft has long been guilty of the "everything-and-the-kitchen-sink" approach to software development. They take the stance that "it might be nice so let's toss it in there". I don't excuse that type of mentality. That's the whole reason why a server install is so huge. Ditto for Office. The price comes not just in disk space, but in all aspects of computing. From a performance perspective, every service or program running takes up CPU overhead and RAM (and swap space). From a security standpoint, each of these is a prospective angle for the latest vulnerability. From a stability standpoint, the more you have running, the harder it is to troubleshoot when things go south. Simple = good. That's a principle I wish more software vendors (including Microsoft, Adobe, etc.) would adhere to.

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