Linux & SysAdmin¶
A structured path from "what is Linux?" to running and securing production servers. Work through the stages in order if you're new, or jump straight to a topic. Every guide targets AlmaLinux 9 / RHEL 9 with Debian/Ubuntu notes inline.
Stage 1 — Foundations¶
Start here if Linux is new to you.
- What is Linux? — kernel vs OS, open source, where it runs
- Linux Distributions — RHEL, Debian, SUSE, Arch, Alpine, and how to choose
- Installing Linux — VMs, cloud, ISOs, partitioning, first boot
- Filesystem Hierarchy — what lives in
/etc,/var,/usr… - Shell Basics — essential commands, pipes, redirection, history
Stage 2 — Core Administration¶
The daily toolkit of a Linux administrator.
- User & Permission Management
- Package Management —
dnf/apt, repos, EPEL - Process Management —
ps,top, signals, jobs - systemd Service Management
- Storage & Filesystems — partitions, LVM,
fstab - Logs & journald
Stage 3 — Networking¶
- Networking Basics —
ip, DNS, nmcli, troubleshooting - SSH — keys, config, tunnels, file transfer
- Firewalls — firewalld, ufw, nftables
Stage 4 — Web Server Stack¶
Serve websites and applications.
- Nginx
- Apache
- PHP & PHP-FPM — LAMP vs LEMP
- Virtual Hosts — multiple sites on one server
- HTTPS with Let's Encrypt