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First encounter with freeBSD

Recently I have Installed FreeBSD on some relatively old hardware Thinkpad X201 :)), here I gather the things that I will learn and had learn through the process

1. Installing FreeBSD

FreeBSD offers a straightforward installation process via its text-based installer.

Key Steps:

  • Download the latest ISO from FreeBSD.org.
  • Boot into the installer and follow the prompts.
  • Partitioning:
  • For ZFS, select Auto (ZFS) for a modern setup.
  • For UFS, choose Manual partitioning for traditional setups.
  • Configure networking (DHCP or static IP).
  • Set the root password and create a user account.

Post-Installation Setup

pkg update && pkg upgrade -y  # Update packages
pkg install sudo bash git     # Install essential tools

2. Basic FreeBSD Commands

FreeBSD uses a mix of traditional Unix commands and its own utilities.

Command Description

freebsd-version Check FreeBSD version
pkg install <package>   Install a package
service <service> start Start a service
ifconfig    Network configuration (legacy)
ipfw    Firewall management
zfs list    List ZFS datasets
bsdinstall  Re-run the installer

3. Managing Services

FreeBSD uses rc.d for service management.

service sshd start      # Start SSH
service nginx enable    # Enable at boot
service nginx restart   # Restart a service
For modern systems, use sysrc:

sysrc nginx_enable=YES  # Enable nginx at boot

4. Networking in FreeBSD

FreeBSD’s networking stack is highly optimized.

Key Config Files: /etc/rc.conf → Network & service settings

/etc/resolv.conf → DNS settings

/etc/hosts → Static host entries

Using PF (Packet Filter) Firewall FreeBSD’s default firewall is PF. Example rules:

# /etc/pf.conf
ext_if = "em0"
block all
pass in on $ext_if proto tcp to port {22, 80, 443}
Enable it with:
sysrc pf_enable=YES
service pf start

5. ZFS: The Ultimate Filesystem

FreeBSD’s integration with ZFS is one of its strongest features.

Basic ZFS Commands:

zpool create mypool mirror /dev/ada0 /dev/ada1  # Create mirrored pool
zfs create mypool/data                         # Create dataset
zfs set compression=lz4 mypool/data            # Enable compression
zfs snapshot mypool/data@backup                # Take snapshot

7. Performance Tuning

FreeBSD is highly tunable. Key optimizations:

Kernel Tweaks (/boot/loader.conf):

kern.ipc.shmseg=1024
kern.maxfiles=200000
Network Tuning (/etc/sysctl.conf):
net.inet.tcp.sendbuf_max=16777216
net.inet.tcp.recvbuf_max=16777216

8. Security Best Practices

Disable root SSH login:

echo "PermitRootLogin no" >> /etc/ssh/sshd_config
service sshd restart
Enable automatic updates:
pkg install cronie
echo "0 3 * * * root /usr/sbin/pkg update -q && /usr/sbin/pkg upgrade -y" >> /etc/crontab