systemd.target(5) - man - phpMan

SYSTEMD.TARGET(5)                          systemd.target                          SYSTEMD.TARGET(5)



NAME
       systemd.target - Target unit configuration

SYNOPSIS
       target.target

DESCRIPTION
       A unit configuration file whose name ends in ".target" encodes information about a target
       unit of systemd, which is used for grouping units and as well-known synchronization points
       during start-up.

       This unit type has no specific options. See systemd.unit(5) for the common options of all
       unit configuration files. The common configuration items are configured in the generic [Unit]
       and [Install] sections. A separate [Target] section does not exist, since no target-specific
       options may be configured.

       Target units do not offer any additional functionality on top of the generic functionality
       provided by units. They exist merely to group units via dependencies (useful as boot
       targets), and to establish standardized names for synchronization points used in dependencies
       between units. Among other things, target units are a more flexible replacement for SysV
       runlevels in the classic SysV init system. (And for compatibility reasons special target
       units such as runlevel3.target exist which are used by the SysV runlevel compatibility code
       in systemd. See systemd.special(7) for details).

AUTOMATIC DEPENDENCIES
   Implicit Dependencies
       There are no implicit dependencies for target units.

   Default Dependencies
       The following dependencies are added unless DefaultDependencies=no is set:

       •   Target units will automatically complement all configured dependencies of type Wants= or
           Requires= with dependencies of type After= unless DefaultDependencies=no is set in the
           specified units. Note that Wants= or Requires= must be defined in the target unit itself
           — if you for example define Wants=some.target in some.service, the automatic ordering
           will not be added.

       •   Target units automatically gain Conflicts= and Before= dependencies against
           shutdown.target.

EXAMPLE
       Example 1. Simple standalone target

           # emergency-net.target

           [Unit]
           Description=Emergency Mode with Networking
           Requires=emergency.target systemd-networkd.service
           After=emergency.target systemd-networkd.service
           AllowIsolate=yes

       When adding dependencies to other units, it's important to check if they set
       DefaultDependencies=. Service units, unless they set DefaultDependencies=no, automatically
       get a dependency on sysinit.target. In this case, both emergency.target and
       systemd-networkd.service have DefaultDependencies=no, so they are suitable for use in this
       target, and do not pull in sysinit.target.

       You can now switch into this emergency mode by running systemctl isolate emergency-net.target
       or by passing the option systemd.unit=emergency-net.target on the kernel command line.

       Other units can have WantedBy=emergency-net.target in the [Install] section. After they are
       enabled using systemctl enable, they will be started before emergency-net.target is started.
       It is also possible to add arbitrary units as dependencies of emergency.target without
       modifying them by using systemctl add-wants.

SEE ALSO
       systemd(1), systemctl(1), systemd.unit(5), systemd.special(7), systemd.directives(7)



systemd 249                                                                        SYSTEMD.TARGET(5)