The BSDs — FreeBSD, OpenBSD and NetBSD
Someone tells you the company's firewall "runs pf on OpenBSD" and the storage box "runs FreeBSD with ZFS". These are not Linux distributions at all. They are a separate branch of the Unix family tree, and a few habits change when you log in to one.
The rule
A BSD is one whole system from one project, not a Linux distro.
The BSDs descend from the Berkeley Software Distribution of Unix. The big difference from Linux: each BSD project develops the kernel and the core tools together as one coherent system, with one set of manual pages. A Linux distro, by contrast, assembles a kernel from one project and tools from many others.
The three best known each have a clear personality:
- FreeBSD: performance and features. It has first-class ZFS storage and jails, an early and lightweight form of isolated environment. Netflix's content-delivery servers are a well-known FreeBSD deployment.
- OpenBSD: security and correctness first, with a small default install. It gave the world OpenSSH, which almost every server uses, and the pf packet filter firewall.
- NetBSD: portability. It runs on a huge range of hardware, old and odd. Its package system, pkgsrc, is also used on other systems.
Things that feel different when you log in:
pkg install nginx # FreeBSD packages
pkg_add nginx # OpenBSD packages
service nginx start # rc scripts instead of systemctl
cat /etc/rc.conf # where services are enabled on FreeBSDThere is no systemd on the BSDs. Services are enabled in /etc/rc.conf and controlled with service. The default shell and some command flags differ from the GNU versions on Linux, so check man rather than assuming.
The shortcut
Match the BSD to the job it is famous for:
- Big storage or network appliance: FreeBSD (ZFS, jails, speed).
- Minimal, hardened firewall or router: OpenBSD (pf, secure defaults).
- Unusual or old hardware: NetBSD (portability).
State the need
A small box that only filters traffic and must be as hard to break into as possible.
The trap is assuming Linux commands and flags behave the same. Many tools share a name but not every option.
Drills
Answer fast — trust the rule.
Which project created OpenSSH?
What is FreeBSD's built-in way to run isolated environments?
Is FreeBSD a Linux distribution?
How do you install nginx on FreeBSD?
Remember
- A BSD is one whole system from one project, not a Linux distro.
- Shortcut: FreeBSD for storage and speed, OpenBSD for security, NetBSD for odd hardware.
- Trap: assuming systemd, apt or GNU command flags are there.