|
NAME | SYNOPSIS | DESCRIPTION | AUTOMATIC DEPENDENCIES | EXAMPLE | SEE ALSO | COLOPHON |
|
SYSTEMD.TARGET(5) systemd.target SYSTEMD.TARGET(5)
systemd.target - Target unit configuration
target.target
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).
Unless DefaultDependencies= is set to no in either of related units
or an explicit ordering dependency is already defined, target units
will implicitly complement all configured dependencies of type Wants=
or Requires= with dependencies of type After=. 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 implicit
ordering will not be added.
All target units automatically gain Conflicts= dependency against
shutdown.target unless DefaultDependencies= is set to no.
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.
systemd(1), systemctl(1), systemd.unit(5), systemd.special(7),
systemd.directives(7)
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2018-02-02. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2018-02-02.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
systemd 234 SYSTEMD.TARGET(5)
Pages that refer to this page: systemctl(1), systemd(1), systemd.unit(5), bootup(7), systemd.directives(7), systemd.index(7), systemd.special(7), lvm2-activation-generator(8), runlevel(8), systemd-sysv-generator(8)
|
HTML rendering created 2018-02-02 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.
|
|