About these notes

Working notes on Linux systems administration. Not tutorials, not official documentation — just things I've had to figure out and don't want to look up for the fourth time. Mostly Debian-based but a lot of it applies anywhere.

No comment section. No newsletter. No tracking. If something here is wrong, it's wrong for me too and I'll fix it eventually.

Articles

• 2026-03-28 fail2ban status check commands Quick reference for checking jail status, viewing banned IPs, and managing bans via the CLI.
• 2026-01-15 Linux filesystem hierarchy notes What goes where and why — /etc, /var, /usr/local, /opt, /proc, /run and the rest.
• 2025-11-30 Bash scripting reference: things I always forget Variables, quoting, conditionals, loops, functions, string manipulation, error handling patterns.
• 2025-09-14 nftables on Debian: a working configuration Switched from iptables. Notes on tables, chains, the inet family, and a real server ruleset.
• 2025-08-05 systemd service unit basics Unit file structure, [Service] options, systemctl commands, and reading logs with journalctl.
• 2025-07-22 OpenSSH hardening checklist sshd_config settings I apply to every new server, with reasons.
• 2025-06-18 Debian package management cheatsheet apt and dpkg commands that matter, sources management, held packages, cleanup.