From the design of root and sudo through package management, boot and GRUB, systemd, logs, scheduled jobs, storage and backups. Thirty lessons that take you to the point where you can be trusted with a server. You build one practice environment you are allowed to break, then delete users, carve up partitions and make the machine refuse to boot — all of it in there. Every piece of command output was produced by actually running it.
The 30 lessons are grouped into eight chapters. Working through them in order is the best way, but you are welcome to read only the parts you are responsible for. Note: administration commands cannot run inside the browser. Use the practice container you build in lesson 1, or a virtual machine you are happy to throw away. Never try them on a production server.
What root actually is, when to use su and when to use sudo, and how to design users and groups. This is the doorway to administration, and where accidents happen most. By the end you are done with "it worked when I set 777" and "just use root for now".
apt and dnf, packages and repositories, and the distribution formats that are neither deb nor rpm. Not just installing things, but where they came from and what they leave behind when removed.
What happens, in what order, between pressing the power button and seeing a login prompt. Configuring GRUB, and recovering a server that will no longer boot from GRUB itself.
On Linux today, working with services means working with systemd. The thinking behind it, driving systemctl, writing your own unit files, and start-up ordering and targets.
You get to grips with the two tiers of journald and rsyslog, put the logs you need where you need them, and stop logrotate letting the disk fill up. Incident response starts with the logs.
The cron syntax, and why a job only fails under cron. One-off scheduling with at, and when to use a systemd timer instead. This kills off "but it works when I type it".
From how a disk appears through partitions, filesystems, mounting, swap and LVM. You get to the point of adding capacity without taking anything down when you run out.
Checking and repairing filesystems, backup and restore, and designing all of it as an ongoing routine. You finish by actually breaking something and recovering it, closing out all 30 lessons.
Once you have finished all 30 lessons, carry the same operational thinking into containers with Docker. If the commands themselves still feel shaky, go back to Linux for Beginners. Membership unlocks every course.