man/systemctl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
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  18   Lesser General Public License for more details.
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  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="systemctl">
  25
  26         <refentryinfo>
  27                 <title>systemctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemctl</refname>
  47                 <refpurpose>Control the systemd system and service manager</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>systemctl</command> may be used to
  60                 introspect and control the state of the
  61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  62                 system and service manager.</para>
  63         </refsect1>
  64
  65         <refsect1>
  66                 <title>Options</title>
  67
  68                 <para>The following options are understood:</para>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><option>-h</option></term>
  73                                 <term><option>--help</option></term>
  74
  75                                 <listitem><para>Prints a short help
  76                                 text and exits.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>--version</option></term>
  81
  82                                 <listitem><para>Prints a short version
  83                                 string and exits.</para></listitem>
  84                         </varlistentry>
  85
  86                         <varlistentry>
  87                                 <term><option>-t</option></term>
  88                                 <term><option>--type=</option></term>
  89
  90                                 <listitem><para>The argument should
  91                                 be a unit type name such as
  92                                 <option>service</option> and
  93                                 <option>socket</option>,
  94                                 or a unit load state such as
  95                                 <option>loaded</option> and
  96                                 <option>masked</option>.
  97                                 </para>
  98
  99                                 <para>If the argument is a unit type,
 100                                 when listing units, limit display to
 101                                 certain unit types. If not specified
 102                                 units of all types will be shown.</para>
 103
 104                                 <para>If the argument is a unit load state,
 105                                 when listing units, limit display to
 106                                 certain unit types. If not specified
 107                                 units of in all load states will be
 108                                 shown.</para>
 109
 110                                 <para>As a special case, if the argument
 111                                 is <option>help</option>, a list of
 112                                 allowed values will be printed and the
 113                                 program will exit.</para>
 114                                 </listitem>
 115                         </varlistentry>
 116
 117                         <varlistentry>
 118                                 <term><option>-p</option></term>
 119                                 <term><option>--property=</option></term>
 120
 121                                 <listitem><para>When showing
 122                                 unit/job/manager properties, limit
 123                                 display to certain properties as
 124                                 specified as argument. If not
 125                                 specified all set properties are
 126                                 shown. The argument should be a
 127                                 property name, such as
 128                                 <literal>MainPID</literal>. If
 129                                 specified more than once all
 130                                 properties with the specified names
 131                                 are shown.</para></listitem>
 132                         </varlistentry>
 133
 134                         <varlistentry>
 135                                 <term><option>-a</option></term>
 136                                 <term><option>--all</option></term>
 137
 138                                 <listitem><para>When listing units,
 139                                 show all units, regardless of their
 140                                 state, including inactive units. When
 141                                 showing unit/job/manager properties,
 142                                 show all properties regardless whether
 143                                 they are set or not.</para></listitem>
 144                         </varlistentry>
 145
 146                         <varlistentry>
 147                                 <term><option>--failed</option></term>
 148
 149                                 <listitem><para>When listing units,
 150                                 show only failed units. Do not confuse
 151                                 with
 152                                 <option>--fail</option>.</para></listitem>
 153                         </varlistentry>
 154
 155                         <varlistentry>
 156                                 <term><option>--full</option></term>
 157
 158                                 <listitem><para>Do not ellipsize unit
 159                                 names, cgroup members, and truncate unit descriptions
 160                                 in the output of
 161                                 <command>list-units</command> and
 162                                 <command>list-jobs</command>.</para></listitem>
 163                         </varlistentry>
 164
 165                         <varlistentry>
 166                                 <term><option>--fail</option></term>
 167
 168                                 <listitem><para>If the requested
 169                                 operation conflicts with a pending
 170                                 unfinished job, fail the command. If
 171                                 this is not specified the requested
 172                                 operation will replace the pending job,
 173                                 if necessary. Do not confuse
 174                                 with
 175                                 <option>--failed</option>.</para></listitem>
 176                         </varlistentry>
 177
 178                         <varlistentry>
 179                                 <term><option>--ignore-dependencies</option></term>
 180
 181                                 <listitem><para>When enqueuing a new
 182                                 job ignore all its dependencies and
 183                                 execute it immediately. If passed no
 184                                 required units of the unit passed will
 185                                 be pulled in, and no ordering
 186                                 dependencies will be honored. This is
 187                                 mostly a debugging and rescue tool for
 188                                 the administrator and should not be
 189                                 used by
 190                                 applications.</para></listitem>
 191                         </varlistentry>
 192
 193                         <varlistentry>
 194                                 <term><option>-i</option></term>
 195                                 <term><option>--ignore-inhibitors</option></term>
 196
 197                                 <listitem><para>When system shutdown
 198                                 or a sleep state is requested, ignore
 199                                 inhibitor locks. Applications can
 200                                 establish inhibitor locks to avoid
 201                                 that certain important operations
 202                                 (such as CD burning or suchlike) are
 203                                 interrupted by system shutdown or a
 204                                 sleep state. Any user may take these
 205                                 locks and privileged users may
 206                                 override these locks. If any locks are
 207                                 taken, shutdown and sleep state
 208                                 requests will normally fail
 209                                 (regardless if privileged or not) and
 210                                 list of active locks is
 211                                 printed. However if
 212                                 <option>--ignore-inhibitors</option>
 213                                 is specified the locks are ignored and
 214                                 not printed, and the operation
 215                                 attempted anyway, possibly requiring
 216                                 additional
 217                                 privileges.</para></listitem>
 218                         </varlistentry>
 219
 220                         <varlistentry>
 221                                 <term><option>-q</option></term>
 222                                 <term><option>--quiet</option></term>
 223
 224                                 <listitem><para>Suppress output to
 225                                 STDOUT in
 226                                 <command>snapshot</command>,
 227                                 <command>is-active</command>,
 228                                 <command>is-failed</command>,
 229                                 <command>enable</command> and
 230                                 <command>disable</command>.</para></listitem>
 231                         </varlistentry>
 232
 233                         <varlistentry>
 234                                 <term><option>--no-block</option></term>
 235
 236                                 <listitem><para>Do not synchronously wait for
 237                                 the requested operation to finish. If this is
 238                                 not specified the job will be verified,
 239                                 enqueued and <command>systemctl</command> will
 240                                 wait until it is completed. By passing this
 241                                 argument it is only verified and
 242                                 enqueued.</para></listitem>
 243                         </varlistentry>
 244
 245                         <varlistentry>
 246                                 <term><option>--no-legend</option></term>
 247
 248                                 <listitem><para>Do not print a legend, i.e.
 249                                 the column headers and the footer with hints.
 250                                 </para></listitem>
 251                         </varlistentry>
 252
 253                         <varlistentry>
 254                                 <term><option>--no-pager</option></term>
 255
 256                                 <listitem><para>Do not pipe output into a
 257                                 pager.</para></listitem>
 258                         </varlistentry>
 259
 260                         <varlistentry>
 261                                 <term><option>--system</option></term>
 262
 263                                 <listitem><para>Talk to the systemd
 264                                 system manager. (Default)</para></listitem>
 265                         </varlistentry>
 266
 267                         <varlistentry>
 268                                 <term><option>--user</option></term>
 269
 270                                 <listitem><para>Talk to the systemd
 271                                 manager of the calling user.</para></listitem>
 272                         </varlistentry>
 273
 274                         <varlistentry>
 275                                 <term><option>--no-wall</option></term>
 276
 277                                 <listitem><para>Don't send wall
 278                                 message before
 279                                 halt, power-off, reboot.</para></listitem>
 280                         </varlistentry>
 281
 282                         <varlistentry>
 283                                 <term><option>--global</option></term>
 284
 285                                 <listitem><para>When used with
 286                                 <command>enable</command> and
 287                                 <command>disable</command>, operate on the
 288                                 global user configuration
 289                                 directory, thus enabling or disabling
 290                                 a unit file globally for all future
 291                                 logins of all users.</para></listitem>
 292                         </varlistentry>
 293
 294                         <varlistentry>
 295                                 <term><option>--no-reload</option></term>
 296
 297                                 <listitem><para>When used with
 298                                 <command>enable</command> and
 299                                 <command>disable</command>, do not
 300                                 implicitly reload daemon configuration
 301                                 after executing the
 302                                 changes.</para></listitem>
 303                         </varlistentry>
 304
 305                         <varlistentry>
 306                                 <term><option>--no-ask-password</option></term>
 307
 308                                 <listitem><para>When used with
 309                                 <command>start</command> and related
 310                                 commands, disables asking for
 311                                 passwords. Background services may
 312                                 require input of a password or
 313                                 passphrase string, for example to
 314                                 unlock system hard disks or
 315                                 cryptographic certificates. Unless
 316                                 this option is specified and the
 317                                 command is invoked from a terminal
 318                                 <command>systemctl</command> will
 319                                 query the user on the terminal for the
 320                                 necessary secrets. Use this option to
 321                                 switch this behavior off. In this case
 322                                 the password must be supplied by some
 323                                 other means (for example graphical
 324                                 password agents) or the service might
 325                                 fail. This also disables querying the
 326                                 user for authentication for privileged
 327                                 operations.</para></listitem>
 328                         </varlistentry>
 329
 330                         <varlistentry>
 331                                 <term><option>--kill-who=</option></term>
 332
 333                                 <listitem><para>When used with
 334                                 <command>kill</command>, choose which
 335                                 processes to kill. Must be one of
 336                                 <option>main</option>,
 337                                 <option>control</option> or
 338                                 <option>all</option> to select whether
 339                                 to kill only the main process of the
 340                                 unit, the control process or all
 341                                 processes of the unit. If omitted
 342                                 defaults to
 343                                 <option>all</option>.</para></listitem>
 344                         </varlistentry>
 345
 346                         <varlistentry>
 347                                 <term><option>-s</option></term>
 348                                 <term><option>--signal=</option></term>
 349
 350                                 <listitem><para>When used with
 351                                 <command>kill</command>, choose which
 352                                 signal to send to selected
 353                                 processes. Must be one of the well
 354                                 known signal specifiers such as
 355                                 SIGTERM, SIGINT or SIGSTOP. If
 356                                 omitted defaults to
 357                                 <option>SIGTERM</option>.</para></listitem>
 358                         </varlistentry>
 359
 360                         <varlistentry>
 361                                 <term><option>-f</option></term>
 362                                 <term><option>--force</option></term>
 363
 364                                 <listitem><para>When used with
 365                                 <command>enable</command>, overwrite any
 366                                 existing conflicting
 367                                 symlinks.</para></listitem>
 368
 369                                 <listitem><para>When used with
 370                                 <command>halt</command>,
 371                                 <command>poweroff</command>,
 372                                 <command>reboot</command> or
 373                                 <command>kexec</command> execute the
 374                                 selected operation without shutting
 375                                 down all units. However, all processes
 376                                 will be killed forcibly and all file
 377                                 systems are unmounted or remounted
 378                                 read-only. This is hence a drastic but
 379                                 relatively safe option to request an
 380                                 immediate reboot. If
 381                                 <option>--force</option> is specified
 382                                 twice for these operations, they will
 383                                 be executed immediately without
 384                                 terminating any processes or umounting
 385                                 any file systems. Warning: specifying
 386                                 <option>--force</option> twice with
 387                                 any of these operations might result
 388                                 in data loss.</para></listitem>
 389                         </varlistentry>
 390
 391                         <varlistentry>
 392                                 <term><option>--root=</option></term>
 393
 394                                 <listitem><para>When used with
 395                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and
 396                                 related commands), use alternative
 397                                 root path when looking for unit
 398                                 files.</para></listitem>
 399                         </varlistentry>
 400
 401                         <varlistentry>
 402                                 <term><option>--runtime</option></term>
 403
 404                                 <listitem><para>When used with
 405                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and related commands), make
 406                                 changes only temporarily, so that they
 407                                 are dropped on the next reboot. This
 408                                 will have the effect that changes are
 409                                 not made in subdirectories of
 410                                 <filename>/etc</filename> but in
 411                                 <filename>/run</filename>, with
 412                                 identical immediate effects, however,
 413                                 since the latter is lost on reboot,
 414                                 the changes are lost
 415                                 too.</para></listitem>
 416                         </varlistentry>
 417
 418                         <varlistentry>
 419                                 <term><option>-H</option></term>
 420                                 <term><option>--host</option></term>
 421
 422                                 <listitem><para>Execute operation
 423                                 remotely. Specify a hostname, or
 424                                 username and hostname separated by @,
 425                                 to connect to. This will use SSH to
 426                                 talk to the remote systemd
 427                                 instance.</para></listitem>
 428                         </varlistentry>
 429
 430                         <varlistentry>
 431                                 <term><option>-P</option></term>
 432                                 <term><option>--privileged</option></term>
 433
 434                                 <listitem><para>Acquire privileges via
 435                                 PolicyKit before executing the
 436                                 operation.</para></listitem>
 437                         </varlistentry>
 438
 439                         <varlistentry>
 440                                 <term><option>-n</option></term>
 441                                 <term><option>--lines=</option></term>
 442
 443                                 <listitem><para>When used with
 444                                 <command>status</command> controls the
 445                                 number of journal lines to show,
 446                                 counting from the most recent
 447                                 ones. Takes a positive integer
 448                                 argument. Defaults to
 449                                 10.</para></listitem>
 450                         </varlistentry>
 451
 452                         <varlistentry>
 453                                 <term><option>-o</option></term>
 454                                 <term><option>--output=</option></term>
 455
 456                                 <listitem><para>When used with
 457                                 <command>status</command> controls the
 458                                 formatting of the journal entries that
 459                                 are shown. For the available choices
 460                                 see
 461                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Defaults
 462                                 to
 463                                 <literal>short</literal>.</para></listitem>
 464                         </varlistentry>
 465
 466                 </variablelist>
 467
 468                 <para>The following commands are understood:</para>
 469
 470                 <variablelist>
 471                         <varlistentry>
 472                                 <term><command>list-units</command></term>
 473
 474                                 <listitem><para>List known units (subject to limitations
 475                                 specified with <option>-t</option>).</para>
 476
 477                                 <para>This is the default command.</para></listitem>
 478                         </varlistentry>
 479                         <varlistentry>
 480                                 <term><command>start [NAME...]</command></term>
 481
 482                                 <listitem><para>Start (activate) one
 483                                 or more units specified on the command
 484                                 line.</para></listitem>
 485                         </varlistentry>
 486                         <varlistentry>
 487                                 <term><command>stop [NAME...]</command></term>
 488
 489                                 <listitem><para>Stop (deactivate) one
 490                                 or more units specified on the command
 491                                 line.</para></listitem>
 492                         </varlistentry>
 493                         <varlistentry>
 494                                 <term><command>reload [NAME...]</command></term>
 495
 496                                 <listitem><para>Asks all units listed
 497                                 on the command line to reload their
 498                                 configuration. Note that this will
 499                                 reload the service-specific
 500                                 configuration, not the unit
 501                                 configuration file of systemd. If you
 502                                 want systemd to reload the
 503                                 configuration file of a unit use the
 504                                 <command>daemon-reload</command>
 505                                 command. In other words: for the
 506                                 example case of Apache, this will
 507                                 reload Apache's
 508                                 <filename>httpd.conf</filename> in the
 509                                 web server, not the
 510                                 <filename>apache.service</filename>
 511                                 systemd unit file. </para>
 512
 513                                 <para>This command should not be
 514                                 confused with the
 515                                 <command>daemon-reload</command> or
 516                                 <command>load</command>
 517                                 commands.</para></listitem>
 518
 519                         </varlistentry>
 520                         <varlistentry>
 521                                 <term><command>restart [NAME...]</command></term>
 522
 523                                 <listitem><para>Restart one or more
 524                                 units specified on the command
 525                                 line. If the units are not running yet
 526                                 they will be
 527                                 started.</para></listitem>
 528                         </varlistentry>
 529                         <varlistentry>
 530                                 <term><command>try-restart [NAME...]</command></term>
 531
 532                                 <listitem><para>Restart one or more
 533                                 units specified on the command
 534                                 line if the units are running. Do
 535                                 nothing if units are not running.
 536                                 Note that for compatibility
 537                                 with Red Hat init scripts
 538                                 <command>condrestart</command> is
 539                                 equivalent to this command.</para></listitem>
 540                         </varlistentry>
 541                         <varlistentry>
 542                                 <term><command>reload-or-restart [NAME...]</command></term>
 543
 544                                 <listitem><para>Reload one or more
 545                                 units if they support it. If not,
 546                                 restart them instead. If the units
 547                                 are not running yet they will be
 548                                 started.</para></listitem>
 549                         </varlistentry>
 550                         <varlistentry>
 551                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 552
 553                                 <listitem><para>Reload one or more
 554                                 units if they support it. If not,
 555                                 restart them instead. Do nothing if
 556                                 the units are not running. Note that
 557                                 for compatibility with SysV init
 558                                 scripts
 559                                 <command>force-reload</command> is
 560                                 equivalent to this
 561                                 command.</para></listitem>
 562                         </varlistentry>
 563                         <varlistentry>
 564                                 <term><command>isolate [NAME]</command></term>
 565
 566                                 <listitem><para>Start the unit
 567                                 specified on the command line and its
 568                                 dependencies and stop all others.</para>
 569
 570                                 <para>This is similar to changing the
 571                                 runlevel in a traditional init system. The
 572                                 <command>isolate</command> command will
 573                                 immediately stop processes that are not
 574                                 enabled in the new unit, possibly including
 575                                 the graphical environment or terminal you
 576                                 are currently using.</para>
 577
 578                                 <para>Note that this works only on units
 579                                 where <option>AllowIsolate=</option> is
 580                                 enabled. See
 581                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 582                                 for details.</para></listitem>
 583                         </varlistentry>
 584                         <varlistentry>
 585                                 <term><command>kill [NAME...]</command></term>
 586
 587                                 <listitem><para>Send a signal to one
 588                                 or more processes of the unit. Use
 589                                 <option>--kill-who=</option> to select
 590                                 which process to kill. Use
 591                                 <option>--kill-mode=</option> to
 592                                 select the kill mode and
 593                                 <option>--signal=</option> to select
 594                                 the signal to send.</para></listitem>
 595                         </varlistentry>
 596                         <varlistentry>
 597                                 <term><command>is-active [NAME...]</command></term>
 598
 599                                 <listitem><para>Check whether any of
 600                                 the specified units are active
 601                                 (i.e. running). Returns an exit code
 602                                 0 if at least one is active, non-zero
 603                                 otherwise. Unless
 604                                 <option>--quiet</option> is specified
 605                                 this will also print the current unit
 606                                 state to STDOUT.</para></listitem>
 607                         </varlistentry>
 608                         <varlistentry>
 609                                 <term><command>is-failed [NAME...]</command></term>
 610
 611                                 <listitem><para>Check whether any of
 612                                 the specified units are failed.
 613                                 Returns an exit code
 614                                 0 if at least one is failed, non-zero
 615                                 otherwise. Unless
 616                                 <option>--quiet</option> is specified
 617                                 this will also print the current unit
 618                                 state to STDOUT.</para></listitem>
 619                         </varlistentry>
 620                         <varlistentry>
 621                                 <term><command>status [NAME...|PID...]</command></term>
 622
 623                                 <listitem><para>Show terse runtime
 624                                 status information about one or more
 625                                 units, followed by most recent log
 626                                 data from the journal. If no units are
 627                                 specified, show all units (subject to
 628                                 limitations specified with
 629                                 <option>-t</option>). If a PID is
 630                                 passed show information about the unit
 631                                 the process belongs to.</para>
 632
 633                                 <para>This function is intended to
 634                                 generate human-readable output. If you
 635                                 are looking for computer-parsable
 636                                 output, use <command>show</command>
 637                                 instead.</para></listitem>
 638                         </varlistentry>
 639                         <varlistentry>
 640                                 <term><command>show [NAME...|JOB...]</command></term>
 641
 642                                 <listitem><para>Show properties of one
 643                                 or more units, jobs or the manager
 644                                 itself. If no argument is specified
 645                                 properties of the manager will be
 646                                 shown. If a unit name is specified
 647                                 properties of the unit is shown, and
 648                                 if a job id is specified properties of
 649                                 the job is shown. By default, empty
 650                                 properties are suppressed. Use
 651                                 <option>--all</option> to show those
 652                                 too. To select specific properties to
 653                                 show use
 654                                 <option>--property=</option>. This
 655                                 command is intended to be used
 656                                 whenever computer-parsable output is
 657                                 required. Use
 658                                 <command>status</command> if you are
 659                                 looking for formatted human-readable
 660                                 output.</para></listitem>
 661                         </varlistentry>
 662                         <varlistentry>
 663                                 <term><command>help [NAME...|PID...]</command></term>
 664
 665                                 <listitem><para>Show manual pages for
 666                                 one or more units, if available. If a
 667                                 PID is passed the manual pages for the
 668                                 unit the process of the PID belongs to
 669                                 is shown.</para></listitem>
 670                         </varlistentry>
 671                         <varlistentry>
 672                                 <term><command>reset-failed [NAME...]</command></term>
 673
 674                                 <listitem><para>Reset the
 675                                 '<literal>failed</literal>' state of the
 676                                 specified units, or if no unit name is
 677                                 passed of all units. When a unit fails
 678                                 in some way (i.e. process exiting with
 679                                 non-zero error code, terminating
 680                                 abnormally or timing out) it will
 681                                 automatically enter the
 682                                 '<literal>failed</literal>' state and
 683                                 its exit code and status is recorded
 684                                 for introspection by the administrator
 685                                 until the service is restarted or
 686                                 reset with this
 687                                 command.</para></listitem>
 688                         </varlistentry>
 689
 690                         <varlistentry>
 691                                 <term><command>list-unit-files</command></term>
 692
 693                                 <listitem><para>List installed unit files.
 694                                 </para></listitem>
 695                         </varlistentry>
 696
 697                         <varlistentry>
 698                                 <term><command>enable [NAME...]</command></term>
 699
 700                                 <listitem><para>Enable one or
 701                                 more unit files or unit file
 702                                 instances, as specified on the
 703                                 command line. This will create a
 704                                 number of symlinks as encoded in
 705                                 the <literal>[Install]</literal>
 706                                 sections of the unit files. After
 707                                 the symlinks have been created the
 708                                 systemd configuration is reloaded
 709                                 (in a way that is equivalent to
 710                                 <command>daemon-reload</command>)
 711                                 to ensure the changes are taken into
 712                                 account immediately. Note that this
 713                                 does not have the effect that any of
 714                                 the units enabled are also started at
 715                                 the same time.  If this is desired
 716                                 a separate <command>start</command>
 717                                 command must be invoked for the unit.
 718                                 Also note that in case of instance
 719                                 enablement, symlinks named same as
 720                                 instances are created in install
 721                                 location, however they all point to
 722                                 the same template unit file.</para>
 723
 724                                 <para>This command will
 725                                 print the actions executed. This
 726                                 output may be suppressed by passing
 727                                 <option>--quiet</option>.</para>
 728
 729                                 <para>Note that this operation creates
 730                                 only the suggested symlinks for the
 731                                 units. While this command is the
 732                                 recommended way to manipulate the unit
 733                                 configuration directory, the
 734                                 administrator is free to make
 735                                 additional changes manually, by
 736                                 placing or removing symlinks in the
 737                                 directory. This is particularly useful
 738                                 to create configurations that deviate
 739                                 from the suggested default
 740                                 installation. In this case the
 741                                 administrator must make sure to invoke
 742                                 <command>daemon-reload</command>
 743                                 manually as necessary, to ensure his
 744                                 changes are taken into account.</para>
 745
 746                                 <para>Enabling units should not be
 747                                 confused with starting (activating)
 748                                 units, as done by the
 749                                 <command>start</command>
 750                                 command. Enabling and starting units
 751                                 is orthogonal: units may be enabled
 752                                 without being started and started
 753                                 without being enabled. Enabling simply
 754                                 hooks the unit into various suggested
 755                                 places (for example, so that the unit
 756                                 is automatically started on boot or
 757                                 when a particular kind of hardware is
 758                                 plugged in). Starting actually spawns
 759                                 the daemon process (in case of service
 760                                 units), or binds the socket (in case
 761                                 of socket units), and so
 762                                 on.</para>
 763
 764                                 <para>Depending on whether
 765                                 <option>--system</option>,
 766                                 <option>--user</option> or
 767                                 <option>--global</option> is specified
 768                                 this enables the unit for the system,
 769                                 for the calling user only
 770                                 or for all future logins of all
 771                                 users. Note that in the latter case no
 772                                 systemd daemon configuration is
 773                                 reloaded.</para>
 774                                 </listitem>
 775                         </varlistentry>
 776
 777                         <varlistentry>
 778                                 <term><command>disable [NAME...]</command></term>
 779
 780                                 <listitem><para>Disables one or more
 781                                 units. This removes all symlinks to
 782                                 the specified unit files from the unit
 783                                 configuration directory, and hence
 784                                 undoes the changes made by
 785                                 <command>enable</command>. Note
 786                                 however that this removes
 787                                 all symlinks to the unit files
 788                                 (i.e. including manual additions), not
 789                                 just those actually created by
 790                                 <command>enable</command>. This call
 791                                 implicitly reloads the systemd daemon
 792                                 configuration after completing the
 793                                 disabling of the units. Note that this
 794                                 command does not implicitly stop the
 795                                 units that are being disabled. If this
 796                                 is desired an additional
 797                                 <command>stop</command> command should
 798                                 be executed afterwards.</para>
 799
 800                                 <para>This command will print the
 801                                 actions executed. This output may be
 802                                 suppressed by passing
 803                                 <option>--quiet</option>.</para>
 804                                 </listitem>
 805
 806                                 <para>This command honors
 807                                 <option>--system</option>,
 808                                 <option>--user</option>,
 809                                 <option>--global</option> in a similar
 810                                 way as
 811                                 <command>enable</command>.</para>
 812                         </varlistentry>
 813
 814                         <varlistentry>
 815                                 <term><command>is-enabled [NAME...]</command></term>
 816
 817                                 <listitem><para>Checks whether any of
 818                                 the specified unit files are enabled
 819                                 (as with
 820                                 <command>enable</command>). Returns an
 821                                 exit code of 0 if at least one is
 822                                 enabled, non-zero otherwise. Prints
 823                                 the current enable status. To suppress
 824                                 this output use
 825                                 <option>--quiet</option>.</para></listitem>
 826                         </varlistentry>
 827
 828                         <varlistentry>
 829                                 <term><command>reenable [NAME...]</command></term>
 830
 831                                 <listitem><para>Reenable one or more
 832                                 unit files, as specified on the
 833                                 command line. This is a combination of
 834                                 <command>disable</command> and
 835                                 <command>enable</command> and is
 836                                 useful to reset the symlinks a unit is
 837                                 enabled with to the defaults
 838                                 configured in the
 839                                 <literal>[Install]</literal> section
 840                                 of the unit file.</para>
 841                                 </listitem>
 842                         </varlistentry>
 843
 844                         <varlistentry>
 845                                 <term><command>preset [NAME...]</command></term>
 846
 847                                 <listitem><para>Reset one or more unit
 848                                 files, as specified on the command
 849                                 line, to the defaults configured in
 850                                 the preset policy files. This has the
 851                                 same effect as
 852                                 <command>disable</command> or
 853                                 <command>enable</command>, depending
 854                                 how the unit is listed in the preset
 855                                 files. For more information on preset
 856                                 policy format see
 857                                 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 858                                 more information on the concept of
 859                                 presets please consult the <ulink
 860                                 url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
 861                                 document.</para>
 862                                 </listitem>
 863                         </varlistentry>
 864
 865                         <varlistentry>
 866                                 <term><command>mask [NAME...]</command></term>
 867
 868                                 <listitem><para>Mask one or more unit
 869                                 files, as specified on the command
 870                                 line. This will link these units to
 871                                 <filename>/dev/null</filename>, making
 872                                 it impossible to start them. This is a stronger version
 873                                 of <command>disable</command>, since
 874                                 it prohibits all kinds of activation
 875                                 of the unit, including manual
 876                                 activation. Use this option with
 877                                 care.</para>
 878                                 </listitem>
 879                         </varlistentry>
 880
 881                         <varlistentry>
 882                                 <term><command>unmask [NAME...]</command></term>
 883
 884                                 <listitem><para>Unmask one or more
 885                                 unit files, as specified on the
 886                                 command line. This will undo the
 887                                 effect of
 888                                 <command>mask</command>.</para>
 889                                 </listitem>
 890                         </varlistentry>
 891
 892                         <varlistentry>
 893                                 <term><command>link [NAME...]</command></term>
 894
 895                                 <listitem><para>Link a unit file that
 896                                 is not in the unit file search paths
 897                                 into the unit file search path. This
 898                                 requires an absolute path to a unit
 899                                 file. The effect of this can be undone
 900                                 with <command>disable</command>. The
 901                                 effect of this command is that a unit
 902                                 file is available for
 903                                 <command>start</command> and other
 904                                 commands although it isn't installed
 905                                 directly in the unit search
 906                                 path.</para>
 907                                 </listitem>
 908                         </varlistentry>
 909
 910                         <varlistentry>
 911                                 <term><command>load [NAME...]</command></term>
 912
 913                                 <listitem><para>Load one or more units
 914                                 specified on the command line. This
 915                                 will simply load their configuration
 916                                 from disk, but not start them. To
 917                                 start them you need to use the
 918                                 <command>start</command> command which
 919                                 will implicitly load a unit that has
 920                                 not been loaded yet. Note that systemd
 921                                 garbage collects loaded units that are
 922                                 not active or referenced by an active
 923                                 unit. This means that units loaded
 924                                 this way will usually not stay loaded
 925                                 for long. Also note that this command
 926                                 cannot be used to reload unit
 927                                 configuration. Use the
 928                                 <command>daemon-reload</command>
 929                                 command for that. All in all, this
 930                                 command is of little use except for
 931                                 debugging.</para>
 932                                 <para>This command should not be
 933                                 confused with the
 934                                 <command>daemon-reload</command> or
 935                                 <command>reload</command>
 936                                 commands.</para></listitem>
 937                         </varlistentry>
 938                         <varlistentry>
 939                                 <term><command>list-jobs</command></term>
 940
 941                                 <listitem><para>List jobs that are in progress.</para></listitem>
 942                         </varlistentry>
 943                         <varlistentry>
 944                                 <term><command>cancel [JOB...]</command></term>
 945
 946                                 <listitem><para>Cancel one or more
 947                                 jobs specified on the command line by
 948                                 their numeric job
 949                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 950                         </varlistentry>
 951                         <varlistentry>
 952                                 <term><command>dump</command></term>
 953
 954                                 <listitem><para>Dump server
 955                                 status. This will output a (usually
 956                                 very long) human readable manager
 957                                 status dump. Its format is subject to
 958                                 change without notice and should not
 959                                 be parsed by
 960                                 applications.</para></listitem>
 961                         </varlistentry>
 962                         <varlistentry>
 963                                 <term><command>list-dependencies [NAME]</command></term>
 964
 965                                 <listitem><para> Shows required and
 966                                 wanted units of the specified unit. If
 967                                 no unit is specified
 968                                 <filename>default.target</filename> is
 969                                 implied. Target units are recursively
 970                                 expanded.  When <option>--all</option>
 971                                 is passed all other units aare
 972                                 recursively expanded as well.</para>
 973                                 </listitem>
 974                         </varlistentry>
 975                         <varlistentry>
 976                                 <term><command>snapshot [NAME]</command></term>
 977
 978                                 <listitem><para>Create a snapshot. If
 979                                 a snapshot name is specified, the new
 980                                 snapshot will be named after it. If
 981                                 none is specified an automatic
 982                                 snapshot name is generated. In either
 983                                 case, the snapshot name used is
 984                                 printed to STDOUT, unless
 985                                 <option>--quiet</option> is
 986                                 specified.</para>
 987
 988                                 <para>A snapshot refers to a saved
 989                                 state of the systemd manager. It is
 990                                 implemented itself as a unit that is
 991                                 generated dynamically with this
 992                                 command and has dependencies on all
 993                                 units active at the time. At a later
 994                                 time the user may return to this state
 995                                 by using the
 996                                 <command>isolate</command> command on
 997                                 the snapshot unit.</para></listitem>
 998
 999                                 <para>Snapshots are only useful for
1000                                 saving and restoring which units are
1001                                 running or are stopped, they do not
1002                                 save/restore any other
1003                                 state. Snapshots are dynamic and lost
1004                                 on reboot.</para>
1005                         </varlistentry>
1006                         <varlistentry>
1007                                 <term><command>delete [NAME...]</command></term>
1008
1009                                 <listitem><para>Remove a snapshot
1010                                 previously created with
1011                                 <command>snapshot</command>.</para></listitem>
1012                         </varlistentry>
1013                         <varlistentry>
1014                                 <term><command>daemon-reload</command></term>
1015
1016                                 <listitem><para>Reload systemd manager
1017                                 configuration. This will reload all
1018                                 unit files and recreate the entire
1019                                 dependency tree. While the daemon is
1020                                 reloaded, all sockets systemd listens
1021                                 on on behalf of user configuration will
1022                                 stay accessible.</para> <para>This
1023                                 command should not be confused with
1024                                 the <command>load</command> or
1025                                 <command>reload</command>
1026                                 commands.</para></listitem>
1027                         </varlistentry>
1028                         <varlistentry>
1029                                 <term><command>daemon-reexec</command></term>
1030
1031                                 <listitem><para>Reexecute the systemd
1032                                 manager. This will serialize the
1033                                 manager state, reexecute the process
1034                                 and deserialize the state again. This
1035                                 command is of little use except for
1036                                 debugging and package
1037                                 upgrades. Sometimes it might be
1038                                 helpful as a heavy-weight
1039                                 <command>daemon-reload</command>. While
1040                                 the daemon is reexecuted all sockets
1041                                 systemd listens on on behalf of user
1042                                 configuration will stay
1043                                 accessible.</para></listitem>
1044                         </varlistentry>
1045                         <varlistentry>
1046                                 <term><command>show-environment</command></term>
1047
1048                                 <listitem><para>Dump the systemd
1049                                 manager environment block. The
1050                                 environment block will be dumped in
1051                                 straight-forward form suitable for
1052                                 sourcing into a shell script. This
1053                                 environment block will be passed to
1054                                 all processes the manager
1055                                 spawns.</para></listitem>
1056                         </varlistentry>
1057                         <varlistentry>
1058                                 <term><command>set-environment [NAME=VALUE...]</command></term>
1059
1060                                 <listitem><para>Set one or more
1061                                 systemd manager environment variables,
1062                                 as specified on the command
1063                                 line.</para></listitem>
1064                         </varlistentry>
1065                         <varlistentry>
1066                                 <term><command>unset-environment [NAME...]</command></term>
1067
1068                                 <listitem><para>Unset one or more
1069                                 systemd manager environment
1070                                 variables. If only a variable name is
1071                                 specified it will be removed
1072                                 regardless of its value. If a variable
1073                                 and a value are specified the variable
1074                                 is only removed if it has the
1075                                 specified value.</para></listitem>
1076                         </varlistentry>
1077                         <varlistentry>
1078                                 <term><command>default</command></term>
1079
1080                                 <listitem><para>Enter default
1081                                 mode. This is mostly equivalent to
1082                                 <command>start
1083                                 default.target</command>.</para></listitem>
1084                         </varlistentry>
1085                         <varlistentry>
1086                                 <term><command>rescue</command></term>
1087
1088                                 <listitem><para>Enter rescue
1089                                 mode. This is mostly equivalent to
1090                                 <command>isolate
1091                                 rescue.target</command> but also
1092                                 prints a wall message to all
1093                                 users.</para></listitem>
1094                         </varlistentry>
1095                         <varlistentry>
1096                                 <term><command>emergency</command></term>
1097
1098                                 <listitem><para>Enter emergency
1099                                 mode. This is mostly equivalent to
1100                                 <command>isolate
1101                                 emergency.target</command> but also
1102                                 prints a wall message to all
1103                                 users.</para></listitem>
1104                         </varlistentry>
1105                         <varlistentry>
1106                                 <term><command>halt</command></term>
1107
1108                                 <listitem><para>Shut down and halt the
1109                                 system. This is mostly equivalent to
1110                                 <command>start halt.target</command>
1111                                 but also prints a wall message to all
1112                                 users.  If combined with
1113                                 <option>--force</option> shutdown of
1114                                 all running services is skipped,
1115                                 however all processes are killed and
1116                                 all file systems are unmounted or
1117                                 mounted read-only, immediately
1118                                 followed by the system halt.  If
1119                                 <option>--force</option> is specified
1120                                 twice the operation is immediately
1121                                 executed without terminating any
1122                                 processes or unmounting any file
1123                                 systems. This may result in data
1124                                 loss.</para></listitem>
1125                         </varlistentry>
1126                         <varlistentry>
1127                                 <term><command>poweroff</command></term>
1128
1129                                 <listitem><para>Shut down and
1130                                 power-off the system. This is mostly
1131                                 equivalent to <command>start
1132                                 poweroff.target</command> but also
1133                                 prints a wall message to all users. If
1134                                 combined with <option>--force</option>
1135                                 shutdown of all running services is
1136                                 skipped, however all processes are
1137                                 killed and all file systems are
1138                                 unmounted or mounted read-only,
1139                                 immediately followed by the powering
1140                                 off. If <option>--force</option> is
1141                                 specified twice the operation is
1142                                 immediately executed without
1143                                 terminating any processes or
1144                                 unmounting any file systems. This may
1145                                 result in data loss.</para></listitem>
1146                         </varlistentry>
1147                         <varlistentry>
1148                                 <term><command>reboot</command></term>
1149
1150                                 <listitem><para>Shut down and reboot
1151                                 the system. This is mostly equivalent
1152                                 to <command>start
1153                                 reboot.target</command> but also
1154                                 prints a wall message to all users. If
1155                                 combined with <option>--force</option>
1156                                 shutdown of all running services is
1157                                 skipped, however all processes are
1158                                 killed and all file systems are
1159                                 unmounted or mounted read-only,
1160                                 immediately followed by the reboot. If
1161                                 <option>--force</option> is specified
1162                                 twice the operation is immediately
1163                                 executed without terminating any
1164                                 processes or unmounting any file
1165                                 systems. This may result in data
1166                                 loss.</para></listitem>
1167                         </varlistentry>
1168                         <varlistentry>
1169                                 <term><command>kexec</command></term>
1170
1171                                 <listitem><para>Shut down and reboot
1172                                 the system via kexec. This is mostly
1173                                 equivalent to <command>start
1174                                 kexec.target</command> but also prints
1175                                 a wall message to all users. If
1176                                 combined with <option>--force</option>
1177                                 shutdown of all running services is
1178                                 skipped, however all processes are killed
1179                                 and all file systems are unmounted or
1180                                 mounted read-only, immediately
1181                                 followed by the
1182                                 reboot.</para></listitem>
1183                         </varlistentry>
1184                         <varlistentry>
1185                                 <term><command>exit</command></term>
1186
1187                                 <listitem><para>Ask the systemd
1188                                 manager to quit. This is only
1189                                 supported for user service managers
1190                                 (i.e. in conjunction with the
1191                                 <option>--user</option> option) and
1192                                 will fail otherwise.</para></listitem>
1193                         </varlistentry>
1194                         <varlistentry>
1195                                 <term><command>suspend</command></term>
1196
1197                                 <listitem><para>Suspend the
1198                                 system. This will trigger activation
1199                                 of the special
1200                                 <filename>suspend.target</filename>
1201                                 target.</para></listitem>
1202                         </varlistentry>
1203                         <varlistentry>
1204                                 <term><command>hibernate</command></term>
1205
1206                                 <listitem><para>Hibernate the
1207                                 system. This will trigger activation
1208                                 of the special
1209                                 <filename>hibernate.target</filename>
1210                                 target.</para></listitem>
1211                         </varlistentry>
1212                         <varlistentry>
1213                                 <term><command>hybrid-sleep</command></term>
1214
1215                                 <listitem><para>Hibernate and suspend
1216                                 the system. This will trigger
1217                                 activation of the special
1218                                 <filename>hybrid-sleep.target</filename>
1219                                 target.</para></listitem>
1220                         </varlistentry>
1221                         <varlistentry>
1222                                 <term><command>switch-root [ROOT] [INIT]</command></term>
1223
1224                                 <listitem><para>Switches to a
1225                                 different root directory and executes
1226                                 a new system manager process below
1227                                 it. This is intended for usage in
1228                                 initial RAM disks ("initrd"), and will
1229                                 transition from the initrd's system
1230                                 manager process (a.k.a "init" process)
1231                                 to the main system manager
1232                                 process. Takes two arguments: the
1233                                 directory to make the new root
1234                                 directory, and the path to the new
1235                                 system manager binary below it to
1236                                 execute as PID 1. If the latter is
1237                                 omitted or the empty string, a
1238                                 systemd binary will automatically be
1239                                 searched for and used as init. If the
1240                                 system manager path is omitted or
1241                                 equal the empty string the state of
1242                                 the initrd's system manager process is
1243                                 passed to the main system manager,
1244                                 which allows later introspection of the
1245                                 state of the services involved in the
1246                                 initrd boot.</para></listitem>
1247                         </varlistentry>
1248                 </variablelist>
1249
1250         </refsect1>
1251
1252         <refsect1>
1253                 <title>Exit status</title>
1254
1255                 <para>On success 0 is returned, a non-zero failure
1256                 code otherwise.</para>
1257         </refsect1>
1258
1259         <refsect1>
1260                 <title>Environment</title>
1261
1262                 <variablelist class='environment-variables'>
1263                         <varlistentry>
1264                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1265                                 <listitem><para>Pager to use when
1266                                 <option>--no-pager</option> is not given;
1267                                 overrides <varname>$PAGER</varname>.  Setting
1268                                 this to an empty string or the value
1269                                 <literal>cat</literal> is equivalent to passing
1270                                 <option>--no-pager</option>.</para></listitem>
1271                         </varlistentry>
1272                 </variablelist>
1273         </refsect1>
1274
1275         <refsect1>
1276                 <title>See Also</title>
1277                 <para>
1278                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1279                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1280                         <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1281                         <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1282                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1283                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1284                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1285                         <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1286                 </para>
1287         </refsect1>
1288
1289 </refentry>