So for someone who used * linux as main OS for 6 years (and now macOS for 10 years), as well as * linux for servers for just as long, what’s the best way to get started with OpenBSD for servers?

Been eying it for a while, but never gotten started.

This gentleman -> https://twitter.com/romanzolotarev is very passionate about OpenBSD and has some handy guides on his site. A good read and interesting to follow.

Looks like great guides! I'll definitely check them out!

Any cloud VPS service that provides ISO upload will allow you to use OpenBSD. Vultr has OpenBSD 6.4 and 6.5 images pre-configured that you can get installed on a VPS (I’m using a $3.50/mo one).

For an even better experience, try it on an old ThinkPad following this guide [0]. You might like how suspend/resume just works, how your brightness and volume hotkeys just work, how the documentation is awesome, and how all the software you need is just one pkg_add away. I’d say that, compared to Linux on the desktop, OpenBSD can be a much more cohesive experience without a desktop environment installed and without endless configuration for basic features.

[0]: https://www.c0ffee.net/blog/openbsd-on-a-laptop/

If you stick to a tried and true linux release, like OpenSuse, you can have this in Linux. I get excellent hardware support, zypper package management, and an excellent KDE environment.

You can certainly get the it-just-works with a big fat desktop environment like KDE, but if you don’t want that (I personally don’t like it that way), OpenBSD with a plain window manager Just Works better than the equivalent with Linux.

Xfce always works fine for me as well. OpenSUSE has yast for some configuration, it works identically via gui or ncurses.

Thanks, I'll check it out!

And related to this, how's the multi threading story? Once upon a time the folklore was that Linux was doing well, FreeBSD was also good, but the other BSDs were lagging.

Nota bene: my info is from 2010 or even earlier.

I’m no expert on the internals, but with an appropriately configured set of resource limits for your user class, OpenBSD is not much slower than Linux for multithreaded tasks like web browsing. I think they disabled hyperthreading by default for security but I don’t have a device with those capabilities anyway. Firefox spawns many threads on all four cores of my desktop machine and performance is plenty good.

Firefox uses processes, not threads for parallelism, doesn't it?

Yes, but I’m not sure if we’re talking about hardware “threads”, the OS concept of a “thread”, or what Firefox calls a “thread”. Maybe someone who knows more about what they’re talking about could clear it up?