this post was submitted on 27 Aug 2023
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Ive been runing Debian 12 (kde) since bookworm was released and am loving it.

I have recently discovered Devuan which seems to be Debian without systemd - what is the benefit of removing this init system?

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[–] Synthead 170 points 1 year ago* (last edited 1 year ago) (9 children)

It's mostly opinionated. systemd is written in C, uses a consistent config, is documented well, has a lot of good developers behind it, is very fast and light, and does what it's doing very well. Since systemd also is split up into multiple parts, it still follows the "do one thing, do it right" philosophy.

There are some people that believe that systemd "took over" the init systems and configuration demons of their distro, and does "too much." It really does quite a lot: it can replace GRUB (by choice), handle networking config, all the init stuff of course, and much more.

However, I have lived through the fragmented and one-off scripts that glued distros together. Some distros used completely custom scripts for init and networking, so you had to learn "the distro" instead of "learn Linux." They were often slower, had worse error handling, had their own bugs, were written in various scripting languages like tcl, Perl, Bash, POSIX shell, etc. It was a mess.

The somewhat common agreed-upon init system was System V, which is ancient. It used runlevels, nested configuration (remember /etc/rc.d?), and generally, it was mostly used because it was battle tested and did the job. However, it is arguably esoteric by modern standards, and the init philosophy was revised to more modern needs with systemd.

You can probably tell my bias, here. If you have to ask, then you probably don't have a "stance" on systemd, and in my opinion, I would stick with systemd. There were dozens of custom scripts running everywhere and constantly changing, and systemd is such an excellent purpose-built replacement. There's a reason why a lot of distros switched to it!

If you want to experience what other init systems were like, I encourage you to experiment with distros like the one you mentioned. You might even play with virtual machines of old Linux versions to see how we did things a while back. Of course, you probably wouldn't want to run an old version of Linux for daily use.

It should also be mentioned that init systems are fairly integral to distros. For example, if you install Apache httpd, you might get a few systemd .service files. Most distros won't include init files for various init systems. You can write them yourself, but that's quite a lot of work, and lots of packages need specific options when starting them as a service. For this reason, if you decide you want to use a different init system, a distro like the one you mentioned would be the best route.

Great question, and good luck! 👍

[–] [email protected] 17 points 1 year ago (1 children)
[–] [email protected] 11 points 1 year ago

Targets are just a more flexible, granular run level. Plus it can actually handle dependencies.

[–] [email protected] 13 points 1 year ago (1 children)

I was reading about Slackware today and it seems their init system still uses system V and lots of scripts.

So I'd definitely recommend that OS to anyone curious about the old style of init system.

[–] cspiegel 12 points 1 year ago (1 children)

Slackware uses the sysvinit program, but doesn't have System V-style scripts. Which is somewhat confusing, but sysvinit is a basic init program that will just do whatever /etc/inittab tells it, so you can write your startup scripts to work however you want.

Slackware uses what people tend to call a BSD-style init, but it's nothing like the modern BSDs, nor the older BSDs, not really. If you use Slackware, you'll learn how Slackware's init system works, but that's about it.

[–] [email protected] 5 points 1 year ago* (last edited 1 year ago) (1 children)

Ah my mistake. I'm just generally curious about what distros use an alternative to systemd (not that I have any issues with systemd myself but I like variety).

So I googled what init system Slackware uses and read this page.

http://slackware.com/config/init.php (no https)

They mention several scripts on that page and that's why I thought they use scripts.

But I haven't actually used the Slackware yet. Suppose I should though since I'm interested.

[–] cspiegel 4 points 1 year ago (1 children)

No, you're right that it has scripts, they're just not the scripts used by SysV-style init systems. They have different names, are in different locations, and are executed differently.

I used Slackware for several years back in the 90s, and from that experience I'd recommend against learning it. I mean, with VMs today it's simple to try new distributions, so go for it, but I'd put it waaaaay down the list of distributions/operating systems to try. If you have anything else you're interested, put it first. Slackware is standard Linux so there's nothing really special you'd find when using it, and it's just a painful experience in general. I think some people will argue that it helps you "really learn Linux", but I don't think so. It just helps you learn Slackware's idiosyncrasies, and learning pretty much any other distribution would be more beneficial than that.

Slackware has advanced from when I used it in the 90s, but only barely (they have a network-based package manager now, I guess, although it proudly avoids dependency resolution!)

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[–] [email protected] 13 points 1 year ago (1 children)

Some distros used completely custom scripts for init and networking, so you had to learn “the distro” instead of “learn Linux.”

I never really noticed init scripts differing much between distros, but I also didn't play around with many. If the systemD scripts are the same across every system, then this is the first positive thing that I've heard about systemD, so thanks for that.

[–] [email protected] 10 points 1 year ago* (last edited 1 year ago) (1 children)

Init scripts were different, I can confirm. And it was pretty bad if you were doing your job and had to change something on a Debian ~~massive~~ machine, then moved to a red hat one.

[–] [email protected] 3 points 1 year ago

Ah ok, most of my experience has been on debian or derivations in the past decade. It seems weird that the init scripts would need to be different on various systems, I thought they had been pretty well standardized, with variables in the /etc/default/ entries pointing to specific folders or startup options. Ah well.

[–] nomadjoanne 9 points 1 year ago (2 children)

Great answer. I do use systemd boot on one of my systems as well. It isn't exactly systemd itself is it? Simply a boot loader packaged as part of the general systemd boot suite, right?

[–] [email protected] 7 points 1 year ago

Systemd-the-init does depend on some core services and thise need to be used together: Init, logging and IPC. Anything running systemd-init will have journald for logging and IIRC DBus for communication. That's because you need to control a system managing services, so you need to communicate with it and you need to document whatbthe managed services do, so you need logging. And you do want tested and stable code here (reusing something that was widely used in Linux before systemd started) and you do not want that code in the init process either. So systemd-the-init has very simple code tomlog and journald then has thencode needed to stream logs out to disk or to interact with other logging systems.

Everything else is optional and in separate binaries written in a layered architecuture: Each layer uses services provided by the lower layer and offers services to layers higher up in the stack. So lots of services depend on systemd-the-init to start other processes instead of reimplementing that over and over again (thus gaining unified config files for everything that gets started and all the bells and whistles systemd-the-init has already or will pick up later).

Or if you prefer a more negative spin: "Systemd is on huge entangled mess of interdependent binaries" :-)

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[–] [email protected] 57 points 1 year ago* (last edited 1 year ago) (7 children)

Back when systemd was a hot topic I jumped on the bandwagon of using systemd-less distros just because people were telling me how bad it was. To this day I still use openrc but the reality is that systemd works very well and is easy to understand and use. The average user gains no benefit to using another init besides having a better understanding of how the system works.

[–] [email protected] 7 points 1 year ago (1 children)

Well and a faster boot time but it's definitely a learning curve and not really worth it unless you want to try a Distro that ships something else by default (E.g. Alpine).

[–] [email protected] 15 points 1 year ago (2 children)

Faster by how much. My PC boots almost instantly now.

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[–] [email protected] 44 points 1 year ago (3 children)

Short version: some people (I'm one of them) object to systemd on grounds that are 75% philosophical and 25% the kind of tech detail that's more of a matter of taste than anything else. The older sysV init is a smaller program, which means that it has a smaller absolute number of bugs than systemd but also does less on its own. Some of us regard "does less" as a feature rather than a bug.

If systemd works for you and you don't know or care about the philosophical side of the argument, there is probably no benefit for you in switching.

[–] [email protected] 10 points 1 year ago

If systemd works for you and you don’t know or care about the philosophical side of the argument, there is probably no benefit for you in switching.

Exactly this. There are few techincal problems with systemd, but those are so miniscule. I say this as an OpenRC+openrc-init user.

[–] [email protected] 3 points 1 year ago* (last edited 1 year ago) (1 children)

I'm more bothered by the very concept of an integrated supervision suite (running as PID 1 and managing services in runtime). And with the feature creep (not-invented-here syndrome despite being mostly worse on all metrics), the following heavy binding of applications to it's services and that it can't coexist, because of that, with any other init/service manager in a repo without an uncount number of wrapper scripts (some distros tried).

taking a breath Which is why we must have specialized not-systemd distros instead of Choose-your-iso-with-bootloader-X-and-Desktop-Y distros, like Artix does (a not-systemd distro).

The attitude of the devs to technical issues and even security holes is another issue. Systemd is really bad software in that regard.

[–] [email protected] 4 points 1 year ago* (last edited 1 year ago) (1 children)

I basically lump everything you've listed under "philosophy"—poorly chosen design goals and no one at the project doing anything about dev behaviour are not technical flaws per se, as the software is functioning as intended and expected.

systemd and init+OpenRC can exist together in the same repository, though—it just means that the repository also needs to contain both init scripts and service files, both of which are trivially small.

As a Gentoo user since 2005, I've been able to watch the entire debacle as it's progressed, and the various efforts required to keep udev and friends working separately from systemd. (Currently, there are 7 Gentoo packages on the "absolutely requires systemd" list—6 optional daemons that I don't perceive as being very useful, although maybe it's just me, and one library that I've never heard of in any other context. So what's being done to keep it from taking over is working.)

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[–] [email protected] 3 points 1 year ago (1 children)

And the init system systemd replaced was also serial.

[–] [email protected] 4 points 1 year ago* (last edited 1 year ago)

Which means that you trade some speed for making it easier to understand what's going on at any point during init. (Also, OpenRC does have a parallel mode, although it isn't commonly used.) "Serial" isn't inherantly evil, it's just another tradeoff.

[–] [email protected] 42 points 1 year ago (2 children)

Systemd is huge. It's a complex project that covers not just the init system, but also process management, networking, mounts, sessions, many other things. Many people think its monolithic design run counter with the Unix philosophy and wish to use distros without systemd.

[–] [email protected] 48 points 1 year ago

Just to avoid misunderstandings: it's not a monotolithic blob, it is thought so because its first project was a system daemon that manages system services. It is described as "a software suite that provides an array of system components for Linux operating systems.", it is highly modular and offer many optional components that each have their own purpose.

[–] [email protected] 7 points 1 year ago

You're conflating a monorepo and with software monolith.

The development style of systemd is the same as most BSDs, and nobody in their right mind would argue those are counter to the Unix philosophy.

[–] TCB13 36 points 1 year ago* (last edited 1 year ago) (8 children)

Devuan is the outlet of a bunch of people that don't want Linux to evolve, become better and have more flexibility because it violates the UNIX philosophy and/or it is backed by big corp. Systemd was made to tackle a bunch of issues with poorly integrated tools and old architectures that aren't as good as they used to be. If you look at other operating systems, even Apple has a better service manager (launchd).

Systemd is incredibly versatile and most people are unaware of its full potential. Apart from the obvious - start services - it can also run most of a base system with features such as networking (IPv4+IPV6, PBR), NTP, Timers (cron replacement), secure DNS resolutions, isolate processes, setup basic firewalls, port forwarding, centralize logging (in an easy way to query and read), monitor and restart services, detect hardware changes and react to them, mount filesystems, listen for connections in sockets and launch programs to handle incoming data, become your bootloader and... even run full fledged containers both privileged and non-privileged containers. Read this for more details: https://tadeubento.com/2023/systemd-hidden-gems-for-a-better-linux/

The question isn't "what is the benefit of removing this init system", it is "what I'll be missing if I remove it". Although it is possible to do all the above without Systemd, you'll end up with a lot of small integration pains and dozens of processes and different tools all wasting resources.

[–] [email protected] 12 points 1 year ago (2 children)

What worries me about the "systemd does everything as a tightly integrated package" is the too-big-to-fail aspect. I'd be worried that we're seeing a lot of configurations that can't be pulled apart piecemeal-- for example, if you need a feature not available in systemd, or you need to deactivate a systemd component due to an unfixed vulnerability. It feels like there's value in supporting a non-systemd init in the same way there's value for individual packages to support an architecture beyond x86-64-- you get some extra checks that you aren't making assumptions that only work for a specific happy path.

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[–] t0m5k1 35 points 1 year ago

If you're a new user you'd be better off moving on from here and not paying much attention. It's a hot topic full of opinions that everyone will want to force on you.

If you really want to swap out the init system there are some things you need to know.

First, do you need a desktop environment(DE)/window manager(WM)? If so you'll need to find a DE/WM that is not going to demand you use the mainstream init choice which currently is SystemD. If you want to use Gnome from your chosen distro repo's then chances are it will pull SystemD with it.

If you want Gnome but not SystemD you're gonna be building that beast from source every update and for the most part you'll need to go direct to Gnome for any issue/bug you fall over and this too will be painful.

Simpler WMs will be more forgiving and will only rely on either xorg or wayland and will happily run on any init.

There will be other packages out there that also demand you use SystemD, so you'll have to find them and decide if you need them or if there are alternatives that don't have a hard dependency on SystemD.

All the current usable inits are written in C or C+ (except for GNU Shepherd, this is written in guile).

The benefit of swapping out the init system is mainly down to choice, necessity but again this all boils down to what the installation is for and what will it be doing.

For a good run down of the features of the init systems refer to these 2 urls: https://wiki.gentoo.org/wiki/Comparison_of_init_systems https://wiki.archlinux.org/title/Init

All of the init's (except for epoch) provide parallel service startup so if boot time is a focus test each to find the fastest for your platform, Not all of them provide per-service config.

For example one can cobble together: minirc, busybox, syslogng, crond, iptables, lighttpd.

And the end result would be a relatively secure webserver with a small footprint, you could further extend this with nginx to sit in front of lighttpd to provide waf and cache features.

The biggest bug bear with SystemD is that it writes to binary log files and even though it can be configured to generate plain text, if it falls over in a bad way you will still only get a binary log file and if you're in a situation where your only access is say busybox for emergencies. In this instance your only option is to boot from another systemd distro and mount the broken install and run:

$ journalctl --file /var/log/journal/system.journal

Other than that many take issue with SystemD trying replace parts of the system that many say don't really need replacing like sudo, fstab, resolv.conf, etc but again these statements get full of opinion and don't help us truly way up the differences and some of the SystemD alternatives misbehave or become hard dependencies other projects which makes it harder to disable parts and swap out to your chosen package.

I've tried to be more objective with this response and keep as much of my personal opinion out of this, But here is mine:

I don't really like it but to make it easier to get support for my OS I put up with it, I daily drive arch and so must accept it. I could rip it out or run artix, I've gone down this path and got fed up with jumping hurdles to get what I wanted so went back to Arch and now I disable parts of it I don't need/want, have it generate text log files, use openresolv and other choices.

[–] [email protected] 30 points 1 year ago

5 minutes of fame when Debian said "if you want other init systems, maintain them", soon-to-be-Devan folks slammed the door and effectively ruined the chance of multi-init debian by fracturing efforts into their fork instead. But hey, all the news were abuzz about them.

[–] nomme 13 points 1 year ago* (last edited 1 year ago)

what is the benefit of removing this init system?

I don't know anything about Devuan, but the init system is replaced, not removed. You need an init system. Devuan probably has something more barebone than systemd.

[–] [email protected] 12 points 1 year ago* (last edited 1 year ago)

You should embrace systemd. It's actually good. Replaces all startup scripts, logs to a common log, even has scheduled systemd jobs just like cron but better, since they can have proper dependencies. Want to run something right after network stack is up and working? Easy with systemd, more difficult with cron and more hacky.

[–] [email protected] 9 points 1 year ago
[–] [email protected] 9 points 1 year ago

I don't personally like SystemD, but Devuan sucks. They advertise "init freedom", but in reality all of the scripts by default are just sysV init scripts that runit and openrc can't control.

[–] [email protected] 8 points 1 year ago* (last edited 1 year ago)

For a desktop user I don't see any significant benefits to replace systemd. But also no-systemd distros works fine. I was impressed during my try on Alpine Linux, that uses openrc instead. The text printing during OS startup is so short that the terminal didn't scroll. The bluetooth worked flawlessly. But it is a small community distro, and Alpine is limited by other things than the init system. The init system is a problem for people that have to deal with services.

On political aspects, IMO FOSS works easier with small and focused components that can survive with spare time developers. I can't make critisicms on technical aspect, I'm not a good programmer, I just notice systemd seems to works fine. Red hat has man-power and capable of large contributions to Linux distros so they leads the innovations. All big distros switched to systemd, now its hard to avoid.

I would like to support smaller FOSS-friendly systems but I use Arch because I need recent versions and the anti-systemd arch-forks are harder to use. I'm a weak guy.

In short, as an user you should be fine by keeping normal Debian. If for political reasons you want a no systemd distro, the easiest is to use MX Linux with the default init.

[–] [email protected] 6 points 1 year ago (1 children)

SystemD replaced a variety of Linux init systems across different distros almost 10 years ago now but it is still resented by a significant and vocal section of the Linux community.

Devuan is a fork of the Debian Linux distribution that uses sysvinit, runit or OpenRC instead of systemd.

Realistically, at this point, non-SystemD distros are of niche interest. Devuan is one of the distros available in that niche

[–] [email protected] 7 points 1 year ago (5 children)

SystemD replaced a variety of Linux init systems across different distros almost 10 years ago now but it is still resented by a significant and vocal section of the Linux community.

No, it is not. It is always the same few people that repeat the same slogans that failed to convince anyone ten years ago. But that does not really matter: In open source the system that can captures developer mind share wins. Systemd did, nothing else came even close.

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[–] [email protected] 5 points 1 year ago* (last edited 1 year ago) (1 children)

Uhm, it's Systemd.

I think this guy has a few points.

[–] [email protected] 4 points 1 year ago (1 children)

never seen this before, heard of the others but s6 is new to me. very interesting

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