systemd.target

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 247                                                    SYSTEMD.TARGET(5)