Carlos Fenollosa runs BSD

Maybe you have been reading about the release of OpenBSD 6.5 and wonder: What are the differences between Linux and OpenBSD? And, to some extent, other BSDs?

I've also been there at some point and these are my conclusions.

Mandatory disclaimer: this list is aimed at people who are used to Linux and are curious about OpenBSD. It is written to highlight the most important changes from their perspective, not the absolute most important changes from a technical standpoint. Please bear with me.

The first thing to realize is that, on the surface, the changes are minimal. Both are Unix-like. You get a terminal, X Window System, Firefox, LibreOffice. Most free software can be recompiled, though some proprietary software isn't on OpenBSD. Don't expect any visual changes.

Under the hood, there are some big differences with relatively little practical impact:


Do these make little sense to you? I know, I was there. They're philosophical distinctions which ramifications are not immediately visible. They can't be explained, you need to understand them by usage. That's why the typical recommendation is just try OpenBSD and see. So, what are some of the actual, tangible, practical differences? Not many, really. Some are features and some are undesired side effects. With every decision there is a trade-off. Let's see some of them:

OpenBSD is a simpler system. It's very comfortable for sysadmins. All pieces are glued together following the UNIX philosophy, focusing on simplicity. Not sure what this means? Think rc VS systemd

OpenBSD has excellent man pages with practical examples. Use man. Really.

OpenBSD has different default daemons/servers/defaults than Linux.

apache/nginx      httpd
postfix/sendmail  opensmtpd
ntp               openntpd
bash              ksh

…and so on.

These cover 90% of the use cases, while being robust and simpler to admin. Some Linux-kernel-specific software does not work either. Namely, docker.

The same for drivers: OpenBSD has excellent drivers, but a smaller number of them. This includes compatibility drivers: modern/third-party file systems, for example, are not so well supported.

Because of the focus on security and simplicity, and not on speed or optimizations, software runs a bit slower than on Linux. In my experience and in some benchmarks about 10%-20% slower.1

Battery life on laptops is also affected.2 My x230 can run for 5 hours on Linux, 3:30 on OpenBSD. More modern laptops and bigger batteries are a practical solution for most of the people.

Are you telling me that the positives are intangible and the negatives mean a slower system and less software overall?

At the risk of being technically wrong, but with the goal of empathizing with the Linux user, I'll say yes.

In reality: it means that the intangibles are intangible for you. For other people, these features are what draws them to OpenBSD. For me, the system architecture, philosophy, and administration is 10x better than Linux's.

Let me turn the question around: can you live with these drawbacks if it means you will get a more robust, easier to admin, simpler system?

But wait! My goal with this thread was to pique your interest! Go ahead and spin up a VM or install OpenBSD on an old machine and see for yourself.

Life isn't black or white. Maybe OpenBSD can not be your daily OS, but it can be your travel-laptop OS. That is exactly my case.

Actually, my daily driver is macOS, not Linux, because I need to use MS Office and other software which is Windows or Mac only for work. However, I enjoy using OpenBSD much more. The day I retire I will make the full switch.

Well, did I catch your eye or what? What are you waiting for? It's a fantastic Saturday morning, you have the whole weekend in front of you. Download OpenBSD and learn what all the fuzz's about! Thanks for reading! Here are more references:

OpenBSD's website
Project goals
Download instructions
Official FAQ
My first OpenBSD impressions from 2015

You can find me on Twitter.

29 Apr 2019



  1. Test both Linux and OpenBSD on your hardware. Your millage may vary. –Ed 

  2. ThinkPad X1C5 on OpenBSD 6.5 and Ubuntu 19.04 show similar results: 9 hours from 100% to 5%. –Ed 

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