8.2.1 Targets vs. Runlevels
With SysV init the system was booted into a so called “Runlevel”. A runlevel denes
how the system is started and what services are available in the running system. Run-
levels are numbered, the most commonly known ones are 0 (shutting down the system),
3 (multiuser with network) and 5 (multiuser with network and displaymanager).
systemd introduces a new concept by using so-called “target units”. However, it re-
mains fully compatible to the runlevel concept. Target units are named rather than
numbered and serve specic purposes. For example, the targets local-fs.target
and swap.target mount local lesystems and swap spaces.
The target graphical.target provides a multiuser system with network and dis-
playmanager capabilities and is equivalent to runlevel 5. Complex targets, such as
graphical.target act as “meta” targets by combining a subset of other targets.
Since systemd makes it easy to create custom targets by combining existing targets,
it offers great exibility.
The following list shows a list of the most important systemd target units. For a full
list refer to man 7 systemd.special.
Selected systemd Target Units
default.target
The target that is booted by default. Not a “real” target, but rather a symlink to an-
other target like graphic.target. Can be permanently changed via YaST (see
Section 8.1.3.2, “Enabling/Disabling Services with YaST” (page 140)). To change
it for a session, use the Kernel command line option
systemd.unit=<my_target>.target at the boot prompt.
emergency.target
Starts an emergency shell on the console. Only use it at the boot prompt as
systemd.unit=emergency.target.
graphical.target
Starts a system with network, multi-user support and a displaymanager.
halt.target
Shuts down the system.
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