Removing SystemD from Linux

Dec 31, 2024 | Linux
Removing SystemD from Linux

Systemd is great for standardization, but it is insanely bloated. Boot times average around 20 seconds when removing it and using a minimal init system will result in a boot time of only a few seconds. This is a guide on switching to OpenRC.

What do I lose?

Systemd has a LOT of functions and can do the following, but often we swap out to alternatives anyways.

  • Bootloader (Grub is the alternative)
  • Timers (cronie is still widely used instead)
  • Networkd (NetworkManager is almost universally used - same goes for resolved for dns resolution)
  • Auto mount (A few distros use this but often /etc/fstab is used instead)
  • journald (This I will miss… it is a fantastic system log tool)
  • logind (Alternative is elogind - You NEED a login daemon because without it you have to run Xorg as ROOT which only a crazy person would do.)
  • timedated ( universal date and time management)
  • udev (device manager and very useful for using rules to manage device without elevation. Ex. Managing backlight on a laptop)

Switch to OpenRC

The switch is very easy

sudo apt install openrc sysvinit-core
sudo reboot

After restart process is complete install the following packages to fill in any gaps missing with systemd no longer on the system:

sudo apt install elogind libpam-elogind orphan-sysvinit-scripts systemctl procps
sudo reboot

Source: https://lecorbeausvault.wordpress.com/2022/02/07/debian-switching-init-system-easily-openrc-sysvinit-runit/

Prevent Systemd from reinstalling

Create /etc/apt/preferences.d/systemd

Package: systemd
Pin: release *
Pin-Priority: -1
 
Package: *systemd*
Pin: release *
Pin-Priority: -1
 
Package: systemd:i386
Pin: release *
Pin-Priority: -1

APT-Mark holds

sudo apt-mark hold libsystemd0

Systemd vs OpenRC Commands

This is a comparison of the different init systems and run commands.

Source: https://wiki.archlinux.org/title/OpenRC#Usage

SystemDSysVinitOpenRCDescription
systemctl list-unitsrc.d listrc-statusList running services status
systemctl –failedrc-status –crashedCheck failed services
systemctl –allrc-update -v showDisplay all available services.
systemctl (start, stop, restart, status) daemon.servicerc.d (start, stop, restart) daemonrc-service daemon (start, stop, restart, status)Change service state.
systemctl (enable, disable) daemon.servicechkconfig daemon (on, off)rc-update (add, del) daemonTurn service on or off.
systemctl daemon-reloadchkconfig daemon –addCreate or modify configuration.

Creating an OpenRC Service/Daemon

Official Manual page: https://github.com/OpenRC/openrc/blob/master/service-script-guide.md

Create a service script here: /etc/init.d/mydaemon

#!/sbin/openrc-run

command="/usr/sbin/mydaemon"
command_args="-c /etc/mydaemon.conf"
command_user="user:group"
description="super essential service"
pidfile="/var/run/mydaemon.pid"

depend() {
  need localmount
  use logger
}

checkconfig() {
  ...
}

start_pre() {
  # Prevent of double check
  if [ "${RC_CMD}" != "restart" ] ; then
    checkconfig || return $?
  fi
}

stop_pre() {
  if [ "${RC_CMD}" = "restart" ] ; then
    checkconfig || return $?
  fi
}

No Video Planned

Let me know below if you would like a video on this topic.

#Systemd