It is unnecessarily complex to begin with. On top of that, the maintainers are historically not the most open to criticism and try to aggressively push the adoption. So much so that Gnome for example now has very strong dependecies on systemd which makes it very difficult to adopt Gnome on non-systemd systems unless you wanna throw a bunch of patches at it. This hard coupling alone is something that I wouldn't want to rely on, ever.
THIS. Also what problem does it solve that RC scripts can't accomplish? They are much more readable and less complex. What is the benefit of all that added complexity? Even more to the point the business case for it in a professional setting? I've been wondering that for a long time.
Barging in as a Linux guy interested to learn more about the BSDs, so please bear with me.
Something I love with systemd is how I can get very useful stats about a running process, e.g. uptime, cumulated disk & network IOs, current & peak mem usage, etc.
Also the process management (e.g. restart rules & dependency chain) is pretty nice as well.
Is that doable with RC (or other BSD-specific tooling) as well?
It's up to you to say check in your init script if you need to start another service before you.
In terms of uptime or IO and stuff, those metrics are already available. Be that via SNMP or other means. Say you start an nginx in systems, which network and disk usage does it report? Just the main process or all its forks? Same problem in RC.
But that is part of the point. Why in the ever-loving existence should an INIT system provide stats like disk usage? That is NOT what an init system is for.
If you need memory usage or IO usage or uptime, there are so many other tools already integrated into the system that the init system doesn't need to bother.
Init systems should only care about starting, stopping and restarting services. Period. The moment they do more than that, they failed at their core job.
This might came across stronger than meant to, but still holds true.
BSDs are about "keep it simple, keep it single purpose" to a "I can live with that degree". What you get though is outstanding documentation and every component is easily understandable. Prime examples are OpenBSD/FreeBSD PF. That firewall config is just easy to grok, easy to read up on and does 99.999% of what you ever need out of a firewall.
> which network and disk usage does it report? Just the main process or all its forks? Same problem in RC.
Well, the main process and its whole hierarchy, that's what you would expect of an init system monitoring its services, right? And what's nice with systemd is that I can get that from a simple `systemctl status my-service` – of course I could deploy a whole observability stack, but better if I can avoid it.
But there is no need to be defensive, it RC can that's nice, if it can't, then well, too bad.
> there are so many other tools already integrated into the system that the init system doesn't need to bother.
That's what I'd love to hear about, what are the equivalent in the BSDs world.
Best practice would be to pack the service into a jail and then use `ractl` to monitor I/O. Could also then monitor the VNET socket of the jail for network stats.
Or you just grab the PID and get it through that. A bit more manual, but composable.
Spin up a VM, may that be locally or a cloud VM, throw an OpenBSD or a FreeBSD. If you are into mail servers, static http etc then OpenBSD might be your jam. Or try FreeBSD and Jails. Jails are absolutely fantastic.
Ditch the LLMs (not insinuating that you use them, but just in case), try to use the Handbooks and the man pages.
If you ever feel the need that you have so many interdependent services that you need something more complex than RC, then you might have an actual architectural problem to be honest.
>If you ever feel the need that you have so many interdependent services that you need something more complex than RC, then you might have an actual architectural problem to be honest.
It autodiscovers the dependency chain or shit like that? If you got 500+ services that need to be orchestrated you honestly have a very different problem.
I love the simplicity of RC scripts. Easy to understand, easy to debug, it just fucking works.
Simplicity is king, because it's understandable. A behemoth like systemd feels like it requires a PhD.
Systemd also runs 100% against the Unix/Linux philosophy of composability and single purpose.
If you need to make sure that the network stack starts after the usb stack and that starts after the pcie stack and that starts after the … then systemd is considerably easier than SysV init.
You’re handwaving away something that is pretty important. You can say that having 500 services is its own problem but it’s also a reality, even on desktop operating systems.
Addendum to my other reply: it comes down to the "not invented here" problem which always invites weirdly complex solutions to problems that don't exist.
Linux is "just" the kernel and every distro invites new solutions to perceived core problems whereas the BSDs have a whole base system that comes from one source, reducing the chance of a systemd popping up there. Both approaches have their ups and downs.
