Ask HN: Why are supercomputers all running Linux and not BSD?

I would guess it is because linux has a wider hardware support than bsds. As you're building a supercomputer it makes sense to have the faster hardware, implying they are new technology.

Some will say better hardware support. While Linux has better hardware support, i usually find this to be in the more exotic direction.

I think it's simply down to Linux being where the money is. The big players (IBM, Dell, etc) are all actively promoting Linux, and trained personel is also somewhat easy to find. So Linux is "the beast you know".

As for FreeBSD, it might be a technically better platform, but it is living in Linux' shadow.

Personally i run FreeBSD for the excellent documentation, stability, features like ZFS, but nothing i run couldn't just as easily run on Linux.

A comment I found while looking at linux OS that are run on super computers.

"Originally, the top 500 list was populated entirely by proprietary Unix systems from vendors like Cray research, SGI, etc.

In June 1998, the first Linux system entered the top 500 list. By June 2003, Linux systems passed the 25% mark, accounting for 139 of the top 500. By November of 2003, Linux systems comprised over 56% of the top 500. By November 2006, Linux made up more than 75% of the top 500. You get the idea. Over the years, there were a few attempts by microsoft to get into supercomputing, and there were BSD and Mac systems."

Since time is sold on these supercomputers they probably want to run all the same/similar OS so they can compete selling time on them. Also if one person has success everyone else will copy them.

https://linux.slashdot.org/story/17/11/14/2223227/all-500-of...

Slashdot has a ton of comments discussing bsd vs linux on this subject matter, but I didn't see anything to helpful.

My only thought is large companies like netflix use bsd more for CDN because from what I been told bsd has the best I/O handling. Why they don't use it for the rest of there infrastructure? Maybe linux is better at crunching numbers and bsd is better for network and security? No idea thats my best guess.

Scientific high energy physicist here with regional HPC center on the same floor. My observation is that administrators tend to enterprise distributions such as Scientific linux, Suse linux enterprise server (SLES), together with commercial MPI implementations such as IBM MPI and Intel MPI.

On the other hand, people are used to Linux, in my environment literally everybody has Ubuntu on their notebook and workstation. They know how to run their python analysis scripts there and the only thing they have to change when going to the cluster is the adoption of an environment managament system (such as http://modules.sourceforge.net/).

(However, I have to admit I never got in touch with BSD and don't know the differences in user space)

Because BSDs don't scale in that direction.

Dragonfly's design shows promise, but it's not anywhere near ready for supercomputers yet.