What Arch Linux’s switch to systemd means for users
This is based on a post on reddit, published on 2012-09-11.
systemd is a replacement for UNIX System V-style init; instead of
having /etc/init.d/* or /etc/rc.d/* scripts,
systemd runs in the background to manage them.
This has the advantages that there is proper dependency tracking, easing the life of the administrator and allowing for things to be run in parallel safely. It also uses “targets” instead of “init levels”, which just makes more sense. It also means that a target can be started or stopped on the fly, such as mounting or unmounting a drive, which has in the past only been done at boot up and shut down.
The downside is that it is (allegedly) big, bloated1, and does (arguably) more than it should. Why is there a dedicated systemd-fsck? Why does systemd encapsulate the functionality of syslog? That, and it means somebody is standing on my lawn.
The changes an Arch user needs to worry about is
that everything is being moved out of /etc/rc.conf. Arch
users will still have the choice between systemd and SysV-init, but
rc.conf is becoming the SysV-init configuration file, rather than the
general system configuration file. If you will still be using SysV-init,
basically the only thing in rc.conf will be DAEMONS.2 For now there is compatibility for
the variables that used to be there, but that is going away.