Linux / VPS
SSH, systemd, firewall, processes
- 00 Linux & VPS Basics — Roadmap Twelve chapters that take you from a brand-new VPS to a hardened, monitored, ready-to-run-real-software box. No managed cloud. beginner 6 min →
- 01 Picking a VPS What a VPS actually is, how to size one, and how to provision your first box without locking yourself into anyone's ecosystem. beginner 9 min →
- 02 First Login & SSH Hardening Generate a key, disable password login, lock down sshd, and put fail2ban in front. The single most important hour you will ever spend on a VPS. beginner 13 min →
- 03 The Linux Filesystem Where everything lives, why it lives there, and the permissions model that decides what your processes can touch. beginner 12 min →
- 04 Processes & Signals What a Linux process actually is, how fork and exec build the entire universe, and the signals that decide whether your app shuts down cleanly or dies screaming. beginner 12 min →
- 05 systemd Write a unit file. Restart on crash. Survive reboot. Read the journal. The supervisor that runs everything on a modern Linux box. beginner 14 min →
- 06 Sockets, Ports, and What's Listening Every network service is a socket. Every open port is a socket someone bound. The four tools that tell you exactly what your VPS is exposing. intermediate 11 min →
- 07 Firewall Fundamentals How packets actually flow through the kernel, and how to write nftables rules that allow exactly what you want and reject everything else. intermediate 13 min →
- 08 Users, Groups, and Sudo How Linux identifies who is doing what, why services run as their own users, and how sudo gives you root without making you root. intermediate 11 min →
- 09 Logs & journalctl Where every line of output goes on a modern Linux box, how to query it, how to keep the disk from filling up, and when to ship logs off the host. intermediate 11 min →
- 10 Resource Limits ulimit, cgroups, and the OOM killer — three layers of resource control that decide whether your services share the box politely or fight to the death. advanced 13 min →
- 11 Cron & systemd Timers Two ways to run code on a schedule. Which to pick, how to write each, and how to keep scheduled jobs from silently failing for months. advanced 10 min →
- 12 Production Checklist Every step from this track, in one runbook. Provision a fresh VPS and end the day with a hardened, monitored, ready-to-deploy box. advanced 15 min →