What are the best Linux init systems?

Latest Release:August 10, 2014 (v2.1.2)

Programming Language:C

One of the runit project's principles is to keep the code size small. As of version 1.0.0 of runit, the runit.c source contains 330 lines of code; the runsvdir.c source is 274 lines of code, the runsv.c source 509. This minimizes the possibility of bugs introduced by programmer's fault, and makes it more easy for security related people to proofread the source code. The runit core programs have a very small memory footprint and do not allocate memory dynamically. See More

Top Pro

Small and Unix-like

Top Con

Slow

MemorableErlik's Experience

Using it in Void LInix. Runit is easy to understand and conifgure, simple. fast, dependent and portable. See More

Top Pro

Easy to use

Simple scripts linked to the proper directory is all that's needed to bring a service up at boot, and everything is up and running quickly. See More

Top Con

Development stalled

Last patch was back in 2014. See More

GenuineMyesyats's Experience

I use runit on Void Linux. See More

Top Pro

Runs on every POSIX system

PersonableMedusa's Experience

really faster than SysVinit. really simple to config, start/stop services. See More

Top Pro

Supported by several Linux plumbers

Myself included. Development is no longer stalled. See More

marcuswmg's Experience

I use Artix Linux that uses Runit. The OS system runs snappier on my systems over the systemd init Arch Linux I was using before. I am very happy with RUNIT. See More

Top Pro

Init purity - does what an init system must do and nothing more

UNIX philosophy, easy to add new services, easy to manipulate, really fast. See More

Frank Earl's Experience

I'm the current maintainer (yes, the con of it not being supported is not QUITE truth), so I'll be honest and state a bit of bias there. Right now, I'm booting Yocto Embedded Linux distributions using runit thanks to meta-runit. It just simply works. It doesn't expose attack faces on your embedded devices like systemd DOES. It's easier to approach, easier to figure out how to drive it properly. See More

Top Pro

Fast and easy to use

ExceptionalMenhit's Experience

Super easy, works as expected, and fast. See More

Top Pro

Faster boot time than with systemd

Faster on older systems, especially those running on HDDs. See More

Aleksander Svétnik's Experience

It's simplicity is charming. See More

Yoši Yoda's Experience

I use runit with Artix Linux. It's fast and it works. See More

PrinceKael's Experience

So simple to use yet effective. Everything runs fast while also being stable. See More

Check the extensive manual pages! • dinit(8) manpage • dinit-service(5) manpage • dinitcheck(8) manpage • dinitctl(8) manpage See More

Dinit

Top Pro

Well documented

Top Con

Using it as system manager / init

Unfortunately, this is currently supported only on Linux. See More

Specs

License:Apache License 2.0

Latest Release:March 25, 2022 (v0.13.0)

Programming Language:C++

Written with a focus on being secure and correct. See More

Top Pro

Robust

Top Pro

Compact

With a reasonable feature set, but not at the cost of high complexity. See More

Top Pro

Free and Open Source

Distributed under the Apache License version 2.0. See More

Top Pro

Portable

Written in portable C++ code; compiles and runs on a variety of Unix-likes (Linux, various BSDs). See More

Top Pro

Fast startup times

Boots very fast. See More

Every init script needs to reinvent the wheel for every script: argument processing, start/stop/restart/reload/status/whatever processing, finding/clearing/creating PID files, sourcing defaults, building and setting configuration options, so on and so forth. See More

SysVinit

Top Pro

Simple to understand

Top Con

Duplicated implementation for every service

RationalKulullu's Experience

Simple to understand, boots up even with errors and let you fix the issues on a fully booted system. See More

Specs

License:GNU General Public License, version 2

Latest Release:March 28, 2022 (v3.02)

Top Pro

Very stable

Since sysvinit does only one thing (initialize the system) and one thing only, it's very stable and it's impossible for it to fail for any problems unrelated to booting the system. See More

Top Con

Launches a bunch of processes to launch a process

Every init script spawns at least sh/dash/bash, and probably also additional processes such as cat, echo, start-stop-daemon, etc, just to start a single daemon that may not even be needed at the time of boot. This massive overhead results in poor performance, and is a killer for embedded systems. See More

Top Pro

Better boot time and overall performance

It boots up really fast if you use it on a desktop system. See More

Top Con

Can lead to slow boot

Since init starts tasks serially, it has to wait for a certain task to finish in order to start the next one. But when startup processes end up I/O blocked, this leads to considerable delays during boot. See More

Top Pro

Does not stop booting if something fails

It just works, misconfiguration of a third party service wont break booting. See More

Top Con

Fragile

Scripts can be broken easily, specially if your machine state changes constantly (like almost all modern computers). See More

Top Pro

Easy temporary disabling of init scripts

Just rename the script to disable in /etc/init.d, i.e. /etc/init.d/whatever to whatever.disabled to disable the script and rename it back to whatever to enable it again. See More

Top Con

Awkward runtime dependency handling

Comes with a directory tree of symlinks to handle the runtime dependencies with links like S01whatever and K11whatever to start/stop services in a specific runlevel. Writing init scripts that conform to the LSBInit standard of LSB, which does allow to define the dependencies in the script header, doesn't always get you covered. See More

Top Pro

No feature creep

It is an init system nothing more. See More

Top Con

Hard to write sysv-initscripts

As one needs programming skills (opposed to a declarative style). See More

Top Con

Initscripts is not portable

It is virtually impossible to write portable sysvinit-scripts. See More

Top Con

Follows UNIX Philosophy

Yes. This is a CON. Unix Philosophy was a set of guidelines that pretty much made sense in 60 and 70's machines. Trying to follow that instead of the material reality of computing makes software crippled, barely usable and prone to hit dead ends. See More

s6-rc, provides a real Service Manager, a Services Supervisor with Parallel RC and logging, upon demand. The perfect continuation, of Runit. ISC License, is not a barrier, Ibut instead, is so friendly to Open Source and Free Software Licence. See More

s6

Top Pro

The perfect init

Top Con

Not GPL

Operating Systems's Experience

s6-rc, provides a real Service Manager, a Services Supervisor with Parallel RC and logging, upon demand. The perfect continuation, of Runit. See More

Specs

License:ISC License

Latest Release:March 7, 2022 (v2.11.1.0)

Programming Language:C

It depends on libc, has a lot of code. See More

Top Pro

You can use all its components independently

Top Con

Heavy

HilariousHachiman's Experience

Obarun See More

Top Pro

Rock solid

Portable: Linux, BSD, Solaris POSIX. Can be compiled with musl. A lot of features including dependencies service management. Easy to implement with the conjunction of 66 which provide frontend file for service declaration, automatic logger creation,nested supervision tree,user service,instantiated services and many more. Best alternative ever. Work out of the box, PROC was made on Gentoo, Funtoo, Devuan, KISS linux, Adelie, Void, Antix. Default init system and service manager on Obarun and from a long time ago. See More

Top Pro

Runs on every POSIX system

Top Pro

Fastest init

Fastest boot speed. See More

Top Pro

ISC License

One of the main argument that people who are against using systemd is that it does not follow one of UNIX'S core concepts: 'Do one thing and do it well'. Instead, systemd represents a collection of dozens of tightly coupled libraries, with responsibilities that exceed those of a simple init system, since it also tries to handle things like device management, power management, mount points, cron, encryption, syslog, network configuration etc... See More

The GNU Shepherd

Top Pro

It's GNU

systemd

Top Con

UNIX-like isn't the same as the UNIX philosophy

Top Pro

Doesn't cripple your hardware

Instead of assuming your computer is a static machine, systemd is designed with modern computers plug and play design in mind. See More

wolfsnase's Experience

It's not an init system but a trojan horse to replace all system functions Systemd is the the strangler fig pattern applied to an operating system: transform system functionalities by reimplementing them, coexist with the already existing system functionalities for a while and then eliminate them one after another. Its main devs are well known for not caring about bugs they created and a cavalier attitude in general. Comments like "nudging people into the right direction" clearly show that the Systemd devs think they know what's best for the user and that they think they have the entitlement to coerce a whole ecosystem into conformity to Systemd. Server software that has been working well for decades like ISC-DHCPD and BIND is replaced by Systemd's own crappy modules that explode once in a while. Binary logs mean that you can only parse the logs with tools that are aware of the binary format. If you are no longer able to process your logs with the decent tools that are out there, well, bad luck for you. Good luck if your logs get corrupted. Frequent API changes, poor code quality and easter eggs like connecting to Google's DNS by default complete the picture. I'd even switch back to Windows before running Linux with Systemd. See More

Top Con

Too monolithic

It tries to do too much - most people who use systemd aren't even aware of most of the features and don't really use them. It makes can be with complicated to deal with, and it's possible that in a few years this project will be a nightmare to maintain, and the users will feel the effects. See More

Top Pro

Cgroups processes control

Systemd groups all processes by services using Linux's cgroups. Think about memory/cpu/tasks/IO/Net limits and accounting for any service. See More

WittyIstanu's Experience

this garbage is very bloated See More

Top Con

Makes dependent products difficult to port

Software dependent on systemd. Becomes difficult to port to systems that lack systemd. See More

Top Pro

Login management out of the box

Systemd contains a daemon called logind which is used for managing user logins. See More

BraveBabi's Experience

I hate systemd-resolved. Configuration is extremely lacking and it's an absolute pain to disable without disrupting other systemd components. Better to just avoid it. See More

Top Con

Binary logging

A binary log structure means that any tools you want to use to parse it will have to be aware of its format, and know how to deal with the ways it can become corrupted. Otherwise, it's not really possible in the easy sense. See More

Top Pro

GPL Licence

AuthenticAsopus's Experience

A stop job is running... See More

Top Con

It's all or nothing

While it is technically possible to use software without SystemD, it really is true that it is "almost impossible" to use software without it, given that all the hard porting work to other init systems has not been done already for you, or given the fact that you are trying to install unported packages directly from the authors (either from binary, like a DEB file, or from source.) Consider the following: Every major Linux distribution runs SystemD as an only option for init systems. Around %95 of GNU/Linux users use SystemD, give or take. SystemD makes things easier for lazy developers (at a cost, however.) Therefore, most software packages that depend on an init system are developed with inherent and sole SystemD support, in favor of the status quo. While distributions such as Artix-, Gentoo-, and Void Linux have been able to correct packages that depend on SystemD, it is not the easiest to do so. Developers and users wanting to package their own software or build software from source may give up trying to work without SystemD since the software may need to be edited for extra compatibility. See More

Top Pro

Full use of kernel features

No POSIX. See More

Matt Fellenz's Experience

Despite all the flak it gets, it works great and I believe it's a good choice for a Linux system. By doing more than just running scripts, it can do what needs to be done for a modern, dynamic system, namely reacting to hardware changes. Not all Linux systems are static servers. See More

Top Con

Connects to Google DNS servers by default

Top Pro

Free and open source

AffableAnnona's Experience

Best Init ever See More

Top Con

Uses Confirmity as a Philosophy

While it does have many features, SystemD is designed with a pattern of making choices for the user. Since it is not easy for the user to override these decisions, SystemD essentially follows the "knows whats best for the user" philosophy. This may remind the reader of Apple devices, where all the hardware looks the same, all the software looks practically the same, and the only customization options are wallpapers, physical stickers, or phone cases. See More

Top Pro

Easy to manage

ExceptionalMenhit's Experience

Writing unit files as been a massive hassle. Sometimes they don't work as expected, built in logging it a dumpster fire as it stores your logs in a binary format so they're impossible to sort through. If you're logs are big enough See More

Top Con

Overkill as an init system, resulting to unsafe init system

1.2 million code lines... How this monster is controlled with such a huge size, for security leaks and other aspects? How about if, the homed new service fails and your home folder may become unreadable or useless? See More

Top Pro

Default for many popular distributions

Systemd is the default init system for most popular Linux distributions (Arch, Debian, Ubuntu, openSUSE, Fedora, etc.) Therefore there is an insane amount of support behind Systemd. Choosing Systemd means running with the herd, which comes with it's pros and few (or none for some people) cons. See More

Holo Deck's Experience

Systemd is basically one of the main reasons why I switched back to Windows as my main operating system after using 10 years of Linux only. Its just hilarious everytime I update systemd somethink breaks eg I've get dropped to the emergency console for some stupid reason. or a start/stop job is running for a few minutes. See More

Top Con

Aggressive marketing

It's trying to deprive people of freedom of choice. See More

Top Pro

Easy to understand

Mark Penguin's Experience

Easy to understand, default for many distros, it's a shame people hate it for no reason See More

Top Con

Need glibc

Top Pro

Backed by Red Hat

AdventurousBarnumbirr's Experience

Everything just works fine. See More

Top Con

Frequently change APIs

VersatilePapsukkal's Experience

Some configuration that would otherwise work (i.e. autofs) fails on this init for no reason and it's difficult to debug. See More

Top Con

Low-quality code

ReasonableMinthe's Experience

worst init See More

Top Con

The new version does not consider backward compatibility

They just remove the features they think are "incorrect". See More

Oak Bricks's Experience

Its easy to start,stop,enable,and disable serivces See More

Top Con

Makes maintaining a hassle

IncredibleIynx's Experience

Useful tools like journalctl, nspawn, blame, etc. See More

Top Con

Unstable

RespectablePramzimas's Experience

A start job is running... See More

Top Con

Kills background processes after the user logs out by default

LikablePhobos's Experience

5 years See More

Top Con

DDNS is done poorly between DHCP and DNS

Unlike ISC DHCP server/client, systemd-dhcp-client and systemd-dhcp-server cannot do DNSSEC, SVC, and many RRCODE. Stick with Bind9 and isc-dhcp-server instead. See More

PrinceKael's Experience

Buggy, annoying and development suffers from unprecedented scope creep and various other concerns. See More

Top Con

systemd-networkd has poor network event handling for cable disconnect

When you disconnect the LAN cable, nothing happens in systemd-networkd. If you used non-systemd DHCP, you get a new subnet (if it changed). See More

Top Con

systemd-DHCP cannot update subnet after reconnecting LAN from work to home

DHCP client that is builtin the systemd is really simple and rudimentary. Won't work with Verizon/Comcast DHCP ISP servers directly (must use their modem). Other DHCP client can, like ISC dhclient, or dhcpcd. See More

Top Con

Lead developer shows near complete lack of care for standards of quality needed for developing a part of an OS as integral as the init system is

Top Con

Runs only on Linux

The original developers (Canonical) seem to have abandoned this project. At least they're no longer using it in Ubuntu. See More

Upstart

Top Con

Ubuntu abandoned it

Top Pro

Simple .conf file in /etc/init

Top Con

It was just sysvinit or systemd in disguise

It really just offered a barely more intuitive way to create init scripts for the actual init system running behind upstart. See More

Top Pro

Event based startup was fantastic.

Since it is event based, it was simple to have interdependent services emit status messages each other. Service start ordering and shutdown was easily managed in one conf file. The "lazy" start of systemd is BS and is a mess to debug . service unit files have no clue what another service state is. The maintainers add arbitrary timers that add more complexity and more init hangs. The systemd documentation is poor. When a service fails to start (or stop) systemd follows the Microsoft model of not telling the reason why. See More

OpenRC follows the UNIX philosophy of 'do one thing and do it well', while it's true that it has more features than sysvinit, it does not stay away from its primary function with unnecessary added features. See More

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OpenRC

Top Pro

No feature creep

Top Con

No socket activation

OpenRC does not have socket activation yet. It will be added in the future though. See More

ResponsiveEupraxia's Experience

OpenRC works out of the box. I can see where S6 has distinct advantages, I just don't know how to use it well enough to recommend it [yet]. See More

Specs

License:BSD-2-Clause License

Programming Language:C, Shell

Original author(s):Roy Marples

All configuration is done via shell scripts and symlinks. Shell scripts can then use various specialized utilities to ease the development of init scripts. See More

Top Pro

Extremely simple

Top Con

Not widely offered across distrubutions

From Distrowatch, only ten distributions (of which 8 Linux, 1 BSD) officially support OpenRC, and offer it through their standard repos. See More

ProudNemain's Experience

Years of using OpenRC on Gentoo and Debian derivatives. It has very small, readable init scripts, it is rock solid reliable, it is deterministic and always starts my workstations with zfs pools fast and correctly. With systemd zfs mounts sometimes left me with empty directories where a filesystem should be. With systemd I have had episodes of hangs at bootup or shutdown requiring the power-off button to escape. OpenRC has just continued to work properly and administering startup with rc-update / rc-status is straight-forward and clean. OpenRC is deterministic and reliable. See More

Top Pro

Fast

OpenRC builds on top of sysvinit and adds some more useful features (like parallel booting) while still the simplicity that sysvinit is know for. Because of this it generally boots faster than other init systems, especially when parallel booting is enabled. See More

Top Con

Not GPL

Telos's Experience

Fast, efficient, and easy to use. Does what a good init system should, and doesn’t overstep it’s boundaries. See More

Top Pro

UNIX-Like

Does one thing and does it well. See More

's Experience

Fast, Unix-like, easy to understand services, and most importantly simple. See More

Top Pro

Less dependency creep

Using OpenRC does not lock in a distribution by providing specific NON-POSIX extra services which programs then would rely on. See More

Pietro Mele's Experience

Considering adopting an OpenRC based distribution. See More

Top Pro

Portable

It can be ported to other UNIX and UNIX-like operating systems. See More

VersatileMamaQuilla's Experience

Stable, Unix and fast See More

Top Pro

A very balanced compromise

Basically OpenRC doesn't replace SysV init, but rather works with it, providing features that SysV is lacking while taking advantage of its benefits. It's also used by a fair amount of reasonably popular distros and is well supported and developed. See More

EnchantingEkkeko's Experience

Extremely stable for my needs. See More

Top Pro

Very efficient on system resources

Uses multi-core and ram very efficiently. See More

SupportivePhantasos's Experience

5 second boot vs Systemd's 20 or runit's 10 See More

Top Pro

Flexible and extensible

I can add a new startup script for most cases in under five minutes. The ability to quickly insert new applications into the system is a big help. See More

ComposedLulal's Experience

support cgroup See More

Top Pro

Deterministic

It always initializes a system the same way; if OpenRC booted and ran a system properly today, it will boot and run properly tomorrow, and the next day. See More