Linux Handbook¶
A practical reference for running, troubleshooting, and hardening Linux systems — written for people who will actually type these commands on a real machine, not just read about them.
Sections¶
| Section | What it covers |
|---|---|
| Fundamentals | Filesystem hierarchy, permissions, users and groups, the boot process |
| Shell & Bash | Writing scripts that don't silently fail |
| Processes & systemd | Units, targets, journald, service lifecycle |
| Storage, LVM & RAID | Partitions, LVM, software RAID, filesystem choices |
| Linux Networking | The ip command suite, routing, DNS resolution |
| Security & Hardening | SSH, firewalls, least privilege |
| Performance Troubleshooting | CPU, memory, and I/O bottlenecks |
| Web Servers & Databases | Nginx, reverse proxies, common failure modes |
| Docker & Containers | Container networking and isolation |
| Automation & Ansible | Idempotent configuration management |
| Kali Linux & Security Auditing | Lab-only, authorized security testing |
| Advanced Administration | Connection tracking, kernel tuning |
Who this is for¶
You're comfortable with a terminal and you want to go deeper than apt install — whether that's understanding why systemctl restart sometimes doesn't fix a service, or what actually happens when you run ip route add.
Distributions referenced¶
Examples are given for Ubuntu/Debian (apt, systemd, ufw) and RHEL-family (dnf/yum, systemd, firewalld) systems, since those cover the overwhelming majority of production Linux deployments. Differences are called out explicitly where they matter — most of the underlying Linux mechanisms (the kernel, /proc, /sys, systemd itself) are identical either way.