eudev/man/systemctl.xml
2011-01-02 18:17:19 +01:00

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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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<refentry id="systemctl">
<refentryinfo>
<title>systemctl</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemctl</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>systemctl</refname>
<refpurpose>Control the systemd system and service manager</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>systemctl</command> may be used to
introspect and control the state of the
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
system and service manager.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--help</option></term>
<term><option>-h</option></term>
<listitem><para>Prints a short help
text and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--version</option></term>
<listitem><para>Prints a short version
string and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--type=</option></term>
<term><option>-t</option></term>
<listitem><para>When listing units,
limit display to certain unit
types. If not specified units of all
types will be shown. The argument
should be a unit type name such as
<option>service</option>,
<option>socket</option> and
similar.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--property=</option></term>
<term><option>-p</option></term>
<listitem><para>When showing
unit/job/manager information, limit
display to certain properties as
specified as argument. If not
specified all set properties are
shown. The argument should be a
property name, such as
<literal>MainPID</literal>. If
specified more than once all
properties with the specified names
are shown.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--all</option></term>
<term><option>-a</option></term>
<listitem><para>When listing units,
show all units, regardless of their
state, including inactive units. When
showing unit/job/manager information,
show all properties regardless whether
they are set or not.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--full</option></term>
<listitem><para>Do not ellipsize unit
names and truncate unit descriptions
in the output of
<command>list-units</command> and
<command>list-jobs</command>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--fail</option></term>
<listitem><para>If the requested
operation conflicts with a pending
unfinished job, fail the command. If
this is not specified the requested
operation will replace the pending job,
if necessary.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--quiet</option></term>
<term><option>-q</option></term>
<listitem><para>Suppress output to
STDOUT in
<command>snapshot</command>,
<command>is-active</command>,
<command>enable</command> and
<command>disable</command>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-block</option></term>
<listitem><para>Do not synchronously wait for
the requested operation to finish. If this is
not specified the job will be verified,
enqueued and <command>systemctl</command> will
wait until it is completed. By passing this
argument it is only verified and
enqueued.</para></listitem> </varlistentry>
<varlistentry>
<term><option>--no-pager</option></term>
<listitem><para>Do not pipe output into a
pager.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--system</option></term>
<listitem><para>Talk to the systemd
system manager. (Default)</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--user</option></term>
<listitem><para>Talk to the systemd
manager of the calling user.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--order</option></term>
<term><option>--require</option></term>
<listitem><para>When used in
conjunction with the
<command>dot</command> command (see
below), selects which dependencies are
shown in the dependency graph. If
<option>--order</option> is passed
only dependencies of type
<varname>After=</varname> or
<varname>Before=</varname> are
shown. If <option>--require</option>
is passed only dependencies of type
<varname>Requires=</varname>,
<varname>RequiresOverridable=</varname>,
<varname>Requisite=</varname>,
<varname>RequisiteOverridable=</varname>,
<varname>Wants=</varname> and
<varname>Conflicts=</varname> are
shown. If neither is passed, shows
dependencies of all these
types.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-wall</option></term>
<listitem><para>Don't send wall
message before
halt, power-off, reboot.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--global</option></term>
<listitem><para>When used with
<command>enable</command> and
<command>disable</command>, operate on the
global user configuration
directory, thus enabling or disabling
a unit file globally for all future
logins of all users.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-reload</option></term>
<listitem><para>When used with
<command>enable</command> and
<command>disable</command>, do not
implicitly reload daemon configuration
after executing the
changes.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-ask-password</option></term>
<listitem><para>When used with
<command>start</command> and related
commands, disables asking for
passwords. Background services may
require input of a password or
passphrase string, for example to
unlock system hard disks or
cryptographic certificates. Unless
this option is specified and the
command is invoked from a terminal
<command>systemctl</command> will
query the user on the terminal for the
necessary secrets. Use this option to
switch this behavior off. In this
case the password must be supplied by
some other means (for example
graphical password agents) or the
service might fail.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--kill-mode=</option></term>
<listitem><para>When used with
<command>kill</command>, choose the
mode how to kill the selected
processes. Must be one of
<option>control-group</option>,
<option>process-group</option> or
<option>process</option> to select
whether to kill the entire control
group, the process group or only the
selected process itself. If omitted
defaults to
<option>control-group</option> if
<option>--kill-who=all</option> is
set, or <option>process</option>
otherwise. You probably never need to
use this switch.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--kill-who=</option></term>
<listitem><para>When used with
<command>kill</command>, choose which
processes to kill. Must be one of
<option>main</option>,
<option>control</option> or
<option>all</option> to select whether
to kill only the main process of the
unit, the control process or all
processes of the unit. If omitted
defaults to
<option>all</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--signal=</option></term>
<term><option>-s</option></term>
<listitem><para>When used with
<command>kill</command>, choose which
signal to send to selected
processes. Must be one of the well
known signal specifiers such as
SIGTERM, SIGINT or SIGSTOP. If
omitted defaults to
<option>SIGTERM</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--force</option></term>
<term><option>-f</option></term>
<listitem><para>When used with
<command>enable</command>, override any
existing conflicting
symlinks.</para></listitem>
<listitem><para>When used with
<command>halt</command>,
<command>poweroff</command>,
<command>reboot</command> or
<command>kexec</command> execute
selected operation without shutting
down all units. However, all processes
will be killed forcibly and all file
systems are unmounted or remounted
read-only. This is hence a drastic but
relatively safe option to request an
immediate reboot.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--defaults</option></term>
<listitem><para>When used with
<command>disable</command>, ensures
that only the symlinks created by
<command>enable</command> are removed,
not all symlinks pointing to the unit
file that shall be
disabled.</para></listitem>
</varlistentry>
</variablelist>
<para>The following commands are understood:</para>
<variablelist>
<varlistentry>
<term><command>list-units</command></term>
<listitem><para>List known units.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>start [NAME...]</command></term>
<listitem><para>Start (activate) one
or more units specified on the command
line.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>stop [NAME...]</command></term>
<listitem><para>Stop (deactivate) one
or more units specified on the command
line.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>reload [NAME...]</command></term>
<listitem><para>Asks all units listed
on the command line to reload their
configuration. Note that this will
reload the service-specific
configuration, not the unit
configuration file of systemd. If you
want systemd to reload the
configuration file of a unit use the
<command>daemon-reload</command>
command. In other words: for the
example case of Apache, this will
reload Apache's
<filename>httpd.conf</filename> in the
web server, not the
<filename>apache.service</filename>
systemd unit file. </para>
<para>This command should not be
confused with the
<command>daemon-reload</command> or
<command>load</command>
commands.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>restart [NAME...]</command></term>
<listitem><para>Restart one or more
units specified on the command
line. If the units are not running yet
they will be
started.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>try-restart [NAME...]</command></term>
<listitem><para>Restart one or more
units specified on the command
line. If the units are not running yet
the operation will
fail. Note that for compatibility
with Red Hat init scripts
<command>condrestart</command> is
equivalent to this command.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>reload-or-restart [NAME...]</command></term>
<listitem><para>Reload one or more
units if they support it. If not,
restart them instead. If the units
are not running yet they will be
started.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>reload-or-try-restart [NAME...]</command></term>
<listitem><para>Reload one or more
units if they support it. If not,
restart them instead. If the units
are not running yet the operation
will fail. Note that for
compatibility with SysV init scripts
<command>force-reload</command> is
equivalent to this command.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>isolate [NAME]</command></term>
<listitem><para>Start the unit
specified on the command line and its
dependencies and stop all others.</para>
<para>This is similar to changing the
runlevel in a traditional init system. The
<command>isolate</command> command will
immediately stop processes that are not
enabled in the new unit, possibly including
the graphical environment or terminal you
are currently using.</para>
<para>Note that this works only on units
where <option>AllowIsolate=</option> is
enabled. See
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>kill [NAME...]</command></term>
<listitem><para>Send a signal to one
or more processes of the unit. Use
<option>--kill-who=</option> to select
which process to kill. Use
<option>--kill-mode=</option> to
select the kill mode and
<option>--signal=</option> to select
the signal to send.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>is-active [NAME...]</command></term>
<listitem><para>Check whether any of
the specified units are active
(i.e. running). Returns an exit code
0 if at least one is active, non-zero
otherwise. Unless
<option>--quiet</option> is specified
this will also print the current unit
state to STDOUT.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>status [NAME...|PID...]</command></term>
<listitem><para>Show terse runtime
status information about one or more
units. This function is intended to
generate human-readable output. If you
are looking for computer-parsable
output, use <command>show</command>
instead. If a PID is passed
information about the unit the process
of the PID belongs to is
shown.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>show [NAME...|JOB...]</command></term>
<listitem><para>Show properties of one
or more units, jobs or the manager
itself. If no argument is specified
properties of the manager will be
shown. If a unit name is specified
properties of the unit is shown, and
if a job id is specified properties of
the job is shown. By default, empty
properties are suppressed. Use
<option>--all</option> to show those
too. To select specific properties to
show use
<option>--property=</option>. This
command is intended to be used
whenever computer-parsable output is
required. Use
<command>status</command> if you are
looking for formatted human-readable
output.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>reset-failed [NAME...]</command></term>
<listitem><para>Reset the
'<literal>failed</literal>' state of the
specified units, or if no unit name is
passed of all units. When a unit fails
in some way (i.e. process exiting with
non-zero error code, terminating
abnormally or timing out) it will
automatically enter the
'<literal>failed</literal>' state and
its exit code and status is recorded
for introspection by the administrator
until the service is restarted or
reset with this
command.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>enable [NAME...]</command></term>
<listitem><para>Enable one or more
unit files, as specified on the
command line. This will create a
number of symlinks as encoded in the
<literal>[Install]</literal> sections
of the unit files. After the symlinks
have been created the systemd
configuration is reloaded (in a way
that is equivalent to
<command>daemon-reload</command>) to
ensure the changes are taken into
account immediately. Note that this
does not have the effect that any of
the units enabled are also started at
the same time. If this is desired a
separate <command>start</command>
command must be invoked for the
unit.</para>
<para>This command will
print the actions executed. This
output may be suppressed by passing
<option>--quiet</option>.</para>
<para>Note that this operation creates
only the suggested symlinks for the
units. While this command is the
recommended way to manipulate the unit
configuration directory, the
administrator is free to make
additional changes manually, by
placing or removing symlinks in the
directory. This is particularly useful
to create configurations that deviate
from the suggested default
installation. In this case the
administrator must make sure to invoke
<command>daemon-reload</command>
manually as necessary, to ensure his
changes are taken into account.</para>
<para>Enabling units should not be
confused with starting (activating)
units, as done by the
<command>start</command>
command. Enabling and starting units
is orthogonal: units may be enabled
without being started and started
without being enabled. Enabling simply
hooks the unit into various suggested
places (for example, so that the unit
is automatically started on boot or
when a particular kind of hardware is
plugged in). Starting actually spawns
the daemon process (in case of service
units), or binds the socket (in case
of socket units), and so
on.</para>
<para>Depending on whether
<option>--system</option>,
<option>--user</option> or
<option>--global</option> is specified
this enables the unit for the system,
for the calling user only
or for all future logins of all
users. Note that in the latter case no
systemd daemon configuration is
reloaded.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><command>disable [NAME...]</command></term>
<listitem><para>Disables one or more
units. This removes all symlinks to
the specified unit files from the unit
configuration directory, and hence
undoes the changes made by
<command>enable</command>. Note
however that this by default removes
all symlinks to the unit files
(i.e. including manual additions), not
just those actually created by
<command>enable</command>. If only the
symlinks that are suggested by default
shall be removed, pass
<option>--defaults</option>. This
implicitly reloads the systemd daemon
configuration after completing the
disabling of the units. Note that this
command does not implicitly stop the
units that is being disabled. If this
is desired an additional
<command>stop</command>command should
be executed afterwards.</para>
<para>This command will print the
actions executed. This output may be
suppressed by passing
<option>--quiet</option>.</para>
</listitem>
<para>This command honors
<option>--system</option>,
<option>--user</option>,
<option>--global</option> in a similar
way as
<command>enable</command>.</para>
</varlistentry>
<varlistentry>
<term><command>is-enabled [NAME...]</command></term>
<listitem><para>Checks whether any of
the specified unit files is enabled
(as with
<command>enable</command>). Returns an
exit code of 0 if at least one is
enabled, non-zero
otherwise.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>load [NAME...]</command></term>
<listitem><para>Load one or more units
specified on the command line. This
will simply load their configuration
from disk, but not start them. To
start them you need to use the
<command>start</command> command which
will implicitly load a unit that has
not been loaded yet. Note that systemd
garbage collects loaded units that are
not active or referenced by an active
unit. This means that units loaded
this way will usually not stay loaded
for long. Also note that this command
cannot be used to reload unit
configuration. Use the
<command>daemon-reload</command>
command for that. All in all, this
command is of little use except for
debugging.</para>
<para>This command should not be
confused with the
<command>daemon-reload</command> or
<command>reload</command>
commands.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>list-jobs</command></term>
<listitem><para>List jobs that are in progress.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>cancel [JOB...]</command></term>
<listitem><para>Cancel one or more
jobs specified on the command line by
their numeric job
IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>monitor</command></term>
<listitem><para>Monitor unit/job
changes. This is mostly useful for
debugging purposes and prints a line
each time systemd loads or unloads a
unit configuration file, or a unit
property changes.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>dump</command></term>
<listitem><para>Dump server
status. This will output a (usually
very long) human readable manager
status dump. Its format is subject to
change without notice and should not
be parsed by
applications.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>dot</command></term>
<listitem><para>Generate textual
dependency graph description in dot
format for further processing with the
GraphViz
<citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
tool. Use a command line like
<command>systemctl dot | dot -Tsvg >
systemd.svg</command> to generate a
graphical dependency tree. Unless
<option>--order</option> or
<option>--require</option> is passed
the generated graph will show both
ordering and requirement
dependencies.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>snapshot [NAME]</command></term>
<listitem><para>Create a snapshot. If
a snapshot name is specified, the new
snapshot will be named after it. If
none is specified an automatic
snapshot name is generated. In either
case, the snapshot name used is
printed to STDOUT, unless
<option>--quiet</option> is
specified.</para>
<para>A snapshot refers to a saved
state of the systemd manager. It is
implemented itself as a unit that is
generated dynamically with this
command and has dependencies on all
units active at the time. At a later
time the user may return to this state
by using the
<command>isolate</command> command on
the snapshot unit.</para></listitem>
<para>Snapshots are only useful for
saving and restoring which units are
running or are stopped, they do not
save/restore any other
state. Snapshots are dynamic and lost
on reboot.</para>
</varlistentry>
<varlistentry>
<term><command>delete [NAME...]</command></term>
<listitem><para>Remove a snapshot
previously created with
<command>snapshot</command>.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>daemon-reload</command></term>
<listitem><para>Reload systemd manager
configuration. This will reload all
unit files and recreate the entire
dependency tree. While the daemon is
reloaded, all sockets systemd listens
on on behalf of user configuration will
stay accessible.</para> <para>This
command should not be confused with
the <command>load</command> or
<command>reload</command>
commands.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>daemon-reexec</command></term>
<listitem><para>Reexecute the systemd
manager. This will serialize the
manager state, reexecute the process
and deserialize the state again. This
command is of little use except for
debugging and package
upgrades. Sometimes it might be
helpful as a heavy-weight
<command>daemon-reload</command>. While
the daemon is reexecuted all sockets
systemd listens on on behalf of user
configuration will stay
accessible.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>show-environment</command></term>
<listitem><para>Dump the systemd
manager environment block. The
environment block will be dumped in
straight-forward form suitable for
sourcing into a shell script. This
environment block will be passed to
all processes the manager
spawns.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>set-environment [NAME=VALUE...]</command></term>
<listitem><para>Set one or more
systemd manager environment variables,
as specified on the command
line.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>unset-environment [NAME...]</command></term>
<listitem><para>Unset one or more
systemd manager environment
variables. If only a variable name is
specified it will be removed
regardless of its value. If a variable
and a value are specified the variable
is only removed if it has the
specified value.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>default</command></term>
<listitem><para>Enter default
mode. This is mostly equivalent to
<command>start
default.target</command>.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>rescue</command></term>
<listitem><para>Enter rescue
mode. This is mostly equivalent to
<command>isolate
rescue.target</command> but also
prints a wall message to all
users.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>emergency</command></term>
<listitem><para>Enter emergency
mode. This is mostly equivalent to
<command>isolate
emergency.target</command> but also
prints a wall message to all
users.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>halt</command></term>
<listitem><para>Shut down and halt the
system. This is mostly equivalent to
<command>start halt.target</command>
but also prints a wall message to all
users. If
combined with <option>--force</option>
shutdown of all running services is
skipped, however all processes are killed
and all file systems are unmounted or
mounted read-only, immediately
followed by the
system halt.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>poweroff</command></term>
<listitem><para>Shut down and
power-off the system. This is mostly
equivalent to <command>start
poweroff.target</command> but also
prints a wall message to all
users. If
combined with <option>--force</option>
shutdown of all running services is
skipped, however all processes are killed
and all file systems are unmounted or
mounted read-only, immediately
followed by the
powering off.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>reboot</command></term>
<listitem><para>Shut down and
reboot the system. This is mostly
equivalent to <command>start
reboot.target</command> but also
prints a wall message to all
users. If
combined with <option>--force</option>
shutdown of all running services is
skipped, however all processes are killed
and all file systems are unmounted or
mounted read-only, immediately
followed by the
reboot.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>kexec</command></term>
<listitem><para>Shut down and reboot
the system via kexec. This is mostly
equivalent to <command>start
kexec.target</command> but also prints
a wall message to all users. If
combined with <option>--force</option>
shutdown of all running services is
skipped, however all processes are killed
and all file systems are unmounted or
mounted read-only, immediately
followed by the
reboot.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>exit</command></term>
<listitem><para>Ask the systemd
manager to quit. This is only
supported for user service managers
(i.e. in conjunction with the
<option>--user</option> option) and
will fail otherwise.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success 0 is returned, a non-zero failure
code otherwise.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>