FreeBSD vs Linux: Key Differences

Overview

FreeBSD and Linux share Unix heritage but differ significantly in philosophy, structure, and tooling. Understanding these differences is crucial for effective FreeBSD administration.

Base System vs Distributions

Linux

• Kernel + userland from different projects
• Each distribution packages differently
• Package managers vary (apt, yum, pacman)
• Init systems vary (systemd, OpenRC, runit)

FreeBSD

• Complete operating system developed as one project
• Base system is consistent across all installations
• Single package manager (pkg)
• Single init system (rc.d)

Key Command Differences

File System Locations

# FreeBSD directory structure
/           - Root filesystem
/bin        - Essential user commands
/boot       - Boot loader files
/etc        - System configuration
/home       - User home directories (often symlink to /usr/home)
/lib        - Essential shared libraries
/libexec    - System daemons
/mnt        - Mount points
/root       - Root user home
/sbin       - Essential system binaries
/tmp        - Temporary files
/usr        - User utilities and applications
/usr/local  - Third-party applications (pkg installs here)
/var        - Variable data (logs, mail, etc.)

Service Management

Starting/Stopping Services

# Linux (systemd)
systemctl start nginx
systemctl enable nginx
systemctl status nginx

# FreeBSD
service nginx start
sysrc nginx_enable="YES"
service nginx status

Configuration

# FreeBSD - all startup config in one place
cat /etc/rc.conf

# Enable a service
sysrc sshd_enable="YES"

# View current settings
sysrc -a

Networking Differences

# FreeBSD network configuration
# Static IP in /etc/rc.conf:
ifconfig_em0="inet 192.168.1.100 netmask 255.255.255.0"
defaultrouter="192.168.1.1"

# View interfaces
ifconfig

# Restart networking
service netif restart
service routing restart

User Management

# Add user (interactive)
adduser

# Add user to group
pw groupmod wheel -m username

# FreeBSD uses 'wheel' group for sudo access (like Linux)
# Install sudo:
pkg install sudo
visudo  # uncomment wheel group line

Why Choose FreeBSD?

1. ZFS Native Support - Best-in-class filesystem with snapshots, compression, deduplication
2. Jails - Lightweight containerization predating Docker
3. Stability - Complete system tested together
4. Documentation - Exceptional official handbook
5. Ports Collection - Build software with custom options
6. License - Permissive BSD license
7. Security - Capsicum capability framework, pledge