I feel like Im dancing around perhaps the most fundamental piece of my operating system everytime I run and install software. Starting services with systemctl and checking logs with journalctl is the extent of my knowledge.
Do you know of good resources or tutorials for learning how systemd works and how to use it to run software on my desktop and servers? Thanks.
Sorry, I couldn’t resist. /j, obviously.
The man pages.
Write a couple of your own toy services as practice. Write a one-shot that fires at a particular time during boot, a normal service that would run a daemon and a mount service that fires after its dependencies are loaded (like, say, a bind mount that sets up a directory under /run/foo after the backing filesystem is mounted - I do this to make fast ext4 storage available in some parts of the VFS tree while using a btrfs filesystem for everything else.) You can also write file watcher services that fire after changes to a file or directory, I use one of those to mirror /boot/ to /.boot/ on another filesystem so it’s captured by my system snapshots.
I’d start by reading the docs so you have some ideas about what services can do, then you’ll find uses that you wouldn’t have thought of before.
The arch wiki is always a good place to check for these sorts of things, whether or not you use arch btw.
Next up: Learn how to create
.service
file, you may be able to use it from the template provided.Then learn about
target
andunit
Find these on Youtube
Then .timer. Then .mount. Then .automount. Then .socket.
It seems even I have many many many things to learn still
see systemd.unit(5), systemd.service(5), systemd.socket(5), systemd.device(5), systemd.mount(5), systemd.automount(5), systemd.swap(5), systemd.target(5), systemd.path(5), systemd.timer(5), systemd.slice(5), systemd.scope(5) systemd.link(5), systemd.netdev(5), systemd.network(5) and honorable mentions podman-systemd.unit .container, .volume, .network(…again), .kube, .image, .build and .pod
- https://systemd.io/
- https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/using_systemd_unit_files_to_customize_and_optimize_your_system/assembly_working-with-systemd-unit-files_working-with-systemd#con_introduction-to-unit-files_assembly_working-with-systemd-unit-files
- https://www.freedesktop.org/software/systemd/man/latest/
- https://tadeubento.com/2023/systemd-hidden-gems-for-a-better-linux/
Systemd does a lot of stuff I guess it is easier to just lean based on what comes up / you need. There isn’t a single path.
Can’t help you, i avoid it like the plague.
“I don’t use systems btw” 🤓☝️