Advanced Linux System Administration

Every lab is a real AlmaLinux 10 server with SELinux enforcing, and when the work needs a second or third machine you get them. The first four sections deepen what an administrator does every day: finding answers on the machine itself, scripting repeatable work in Bash, special permissions and password ageing, SELinux port labels, booleans and denials, package history, systemd timers, cron and at, process priority, tuning profiles and boot targets. The last section is the services themselves: you build an authoritative, a caching and a secondary DNS server, publish sites with Apache and Nginx over HTTPS with your own certificate authority, share files with Samba, lock down MariaDB access and run Postfix for local mail.

There are no video lectures and no reading-only lessons. Each lab states the task, checks what you actually did on the servers, and shows a worked solution when you ask for one.

What you'll learn

• Find answers with man pages and local documentation, and switch users safely with su and sudo
• Shape your shell with history, aliases and startup files, and write Bash scripts that take input and loop
• Use setuid, setgid and the sticky bit deliberately, and enforce password ageing and account expiry
• Label ports and set booleans for SELinux, and diagnose a denial from the audit log
• Read and undo package history, and schedule work with systemd timers, cron and at
• Set process priority, choose a tuning profile, read performance figures, and change the boot target
• Troubleshoot a network service on one machine from the socket to the firewall
• Run BIND as an authoritative, caching and secondary DNS server with signed zone transfers
• Serve name-based virtual hosts with Apache and put Nginx in front of a private application
• Issue certificates from a training CA, serve HTTPS, and rotate a certificate without downtime
• Share a team directory with Samba, grant least-privilege access in MariaDB, and manage the Postfix queue

Prerequisites

The Linux System Administration labs, or the same ground from experience: the shell, users and permissions, systemd, firewalld, SSH and storage.

Nothing to install. The servers, the terminal and, for the web labs, a browser desktop are in your browser.

Who it's for

Administrators who run services rather than only servers, anyone preparing for a hands-on Enterprise Linux certification, and DevOps engineers who want to understand the machines under their containers.

FAQ

Do I need the first Linux course? Not formally, but these labs assume its habits. If the shell, permissions and systemd are new to you, start there; it is free.

How many times can I launch a lab? Ten launches per lab, one at a time.

Do the labs use more than one machine? The services labs do: a client and one or two servers, already connected.

Do I have to go in order? No. Each lab stands on its own, though the services section builds from DNS to web to the rest.