Init/Replacing udev

From ArchWiki
< Init
Revision as of 18:37, 10 March 2015 by Nous (talk | contribs) (→‎Replacing the systemd package: Remote system reboot trigger)
Jump to navigation Jump to search


eudev is a fork of udev started by the Gentoo project, with the goal of isolation from the init system. It is primarily designed and tested with OpenRC, but is agnostic to any other init systems.

Installation

Install eudevAUR from the Arch User Repository. Alternatively, eudev-gitAUR and eudev-openrcAUR are available, each with differing dependencies.

Warning: This package will remove systemd as it replaces udev. Therefore, you should install an alternative init system and have it boot successfully under that init system prior to installing eudev.

Replacing the systemd package

Tango-view-fullscreen.pngThis article or section needs expansion.Tango-view-fullscreen.png

Reason: Find a statisfactory solution for tmpfiles, cf. openrc-systemdcompatAUR and tmpfiles-configAUR (Discuss in Talk:Init/Replacing udev#)

The systemd packages include several components besides the init system and systemd-udev:

  • systemd libraries linked against software such as Xorg. See #libsystemd.
  • systemd-tmpfiles to create temporary files on system startup
  • systemd-sysusers to allocate system users and groups in pacman .install files

If you have removed systemd without booting to the new init, a reboot is not possible in regular ways. Enable SysRq keys:

# sysctl kernel.sysrq=1

and press Alt-SysRq-S, Alt-SysRq-U and Alt-SysRq-B in succession. This syncs all mounted file systems, remounts all disk as read-only, and reboots the system, respectively. If latter is not possible, press Alt-SysRq-O to poweroff). In case the system is a remote box, you must sync and remount read-only its filesystems before triggering an immediate reboot (edit your filesystems accordingly):

# sync; mount -f /home -o remount,ro ; sync; mount -f / -o remount,ro
# echo b >| /proc/sysrq-trigger

libsystemd

This package will also remove libsystemd as it replaces a part of it. The missing libraries are available from:

  • libsystemd-standaloneAUR — a package group with libraries separated into a package each.
  • eudev-systemdcompatAUR — a package that guts the official libsystemd package and installs the missing libraries.

You also probably want systemd-dummyAUR to satisfy the missing systemd dependency.

Alternatively, you may rebuild packages linked to libsystemd using ABS, or install nosystemd variants from the AUR.

Troubleshooting

Fails to start

Check the init script for eudev (aliased to udev, so /etc/openrc/init.d/udev on an OpenRC setup for example) and ensure the command points to /usr/bin/udev.

netctl

netctl is not compatible due to dependency on systemd libs, instead, use netcfgAUR, avaliable in the AUR.

See also