man/systemctl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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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.
  19
  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.</para></listitem>
 475                         </varlistentry>
 476                         <varlistentry>
 477                                 <term><command>start [NAME...]</command></term>
 478
 479                                 <listitem><para>Start (activate) one
 480                                 or more units specified on the command
 481                                 line.</para></listitem>
 482                         </varlistentry>
 483                         <varlistentry>
 484                                 <term><command>stop [NAME...]</command></term>
 485
 486                                 <listitem><para>Stop (deactivate) one
 487                                 or more units specified on the command
 488                                 line.</para></listitem>
 489                         </varlistentry>
 490                         <varlistentry>
 491                                 <term><command>reload [NAME...]</command></term>
 492
 493                                 <listitem><para>Asks all units listed
 494                                 on the command line to reload their
 495                                 configuration. Note that this will
 496                                 reload the service-specific
 497                                 configuration, not the unit
 498                                 configuration file of systemd. If you
 499                                 want systemd to reload the
 500                                 configuration file of a unit use the
 501                                 <command>daemon-reload</command>
 502                                 command. In other words: for the
 503                                 example case of Apache, this will
 504                                 reload Apache's
 505                                 <filename>httpd.conf</filename> in the
 506                                 web server, not the
 507                                 <filename>apache.service</filename>
 508                                 systemd unit file. </para>
 509
 510                                 <para>This command should not be
 511                                 confused with the
 512                                 <command>daemon-reload</command> or
 513                                 <command>load</command>
 514                                 commands.</para></listitem>
 515
 516                         </varlistentry>
 517                         <varlistentry>
 518                                 <term><command>restart [NAME...]</command></term>
 519
 520                                 <listitem><para>Restart one or more
 521                                 units specified on the command
 522                                 line. If the units are not running yet
 523                                 they will be
 524                                 started.</para></listitem>
 525                         </varlistentry>
 526                         <varlistentry>
 527                                 <term><command>try-restart [NAME...]</command></term>
 528
 529                                 <listitem><para>Restart one or more
 530                                 units specified on the command
 531                                 line if the units are running. Do
 532                                 nothing if units are not running.
 533                                 Note that for compatibility
 534                                 with Red Hat init scripts
 535                                 <command>condrestart</command> is
 536                                 equivalent to this command.</para></listitem>
 537                         </varlistentry>
 538                         <varlistentry>
 539                                 <term><command>reload-or-restart [NAME...]</command></term>
 540
 541                                 <listitem><para>Reload one or more
 542                                 units if they support it. If not,
 543                                 restart them instead. If the units
 544                                 are not running yet they will be
 545                                 started.</para></listitem>
 546                         </varlistentry>
 547                         <varlistentry>
 548                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 549
 550                                 <listitem><para>Reload one or more
 551                                 units if they support it. If not,
 552                                 restart them instead. Do nothing if
 553                                 the units are not running. Note that
 554                                 for compatibility with SysV init
 555                                 scripts
 556                                 <command>force-reload</command> is
 557                                 equivalent to this
 558                                 command.</para></listitem>
 559                         </varlistentry>
 560                         <varlistentry>
 561                                 <term><command>isolate [NAME]</command></term>
 562
 563                                 <listitem><para>Start the unit
 564                                 specified on the command line and its
 565                                 dependencies and stop all others.</para>
 566
 567                                 <para>This is similar to changing the
 568                                 runlevel in a traditional init system. The
 569                                 <command>isolate</command> command will
 570                                 immediately stop processes that are not
 571                                 enabled in the new unit, possibly including
 572                                 the graphical environment or terminal you
 573                                 are currently using.</para>
 574
 575                                 <para>Note that this works only on units
 576                                 where <option>AllowIsolate=</option> is
 577                                 enabled. See
 578                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 579                                 for details.</para></listitem>
 580                         </varlistentry>
 581                         <varlistentry>
 582                                 <term><command>kill [NAME...]</command></term>
 583
 584                                 <listitem><para>Send a signal to one
 585                                 or more processes of the unit. Use
 586                                 <option>--kill-who=</option> to select
 587                                 which process to kill. Use
 588                                 <option>--kill-mode=</option> to
 589                                 select the kill mode and
 590                                 <option>--signal=</option> to select
 591                                 the signal to send.</para></listitem>
 592                         </varlistentry>
 593                         <varlistentry>
 594                                 <term><command>is-active [NAME...]</command></term>
 595
 596                                 <listitem><para>Check whether any of
 597                                 the specified units are active
 598                                 (i.e. running). Returns an exit code
 599                                 0 if at least one is active, non-zero
 600                                 otherwise. Unless
 601                                 <option>--quiet</option> is specified
 602                                 this will also print the current unit
 603                                 state to STDOUT.</para></listitem>
 604                         </varlistentry>
 605                         <varlistentry>
 606                                 <term><command>is-failed [NAME...]</command></term>
 607
 608                                 <listitem><para>Check whether any of
 609                                 the specified units are failed.
 610                                 Returns an exit code
 611                                 0 if at least one is failed, non-zero
 612                                 otherwise. Unless
 613                                 <option>--quiet</option> is specified
 614                                 this will also print the current unit
 615                                 state to STDOUT.</para></listitem>
 616                         </varlistentry>
 617                         <varlistentry>
 618                                 <term><command>status [NAME...|PID...]</command></term>
 619
 620                                 <listitem><para>Show terse runtime
 621                                 status information about one or more
 622                                 units, followed by its most recent log
 623                                 data from the journal. This function
 624                                 is intended to generate human-readable
 625                                 output. If you are looking for
 626                                 computer-parsable output, use
 627                                 <command>show</command> instead. If a
 628                                 PID is passed information about the
 629                                 unit the process of the PID belongs to
 630                                 is shown.</para></listitem>
 631                         </varlistentry>
 632                         <varlistentry>
 633                                 <term><command>show [NAME...|JOB...]</command></term>
 634
 635                                 <listitem><para>Show properties of one
 636                                 or more units, jobs or the manager
 637                                 itself. If no argument is specified
 638                                 properties of the manager will be
 639                                 shown. If a unit name is specified
 640                                 properties of the unit is shown, and
 641                                 if a job id is specified properties of
 642                                 the job is shown. By default, empty
 643                                 properties are suppressed. Use
 644                                 <option>--all</option> to show those
 645                                 too. To select specific properties to
 646                                 show use
 647                                 <option>--property=</option>. This
 648                                 command is intended to be used
 649                                 whenever computer-parsable output is
 650                                 required. Use
 651                                 <command>status</command> if you are
 652                                 looking for formatted human-readable
 653                                 output.</para></listitem>
 654                         </varlistentry>
 655                         <varlistentry>
 656                                 <term><command>help [NAME...|PID...]</command></term>
 657
 658                                 <listitem><para>Show manual pages for
 659                                 one or more units, if available. If a
 660                                 PID is passed the manual pages for the
 661                                 unit the process of the PID belongs to
 662                                 is shown.</para></listitem>
 663                         </varlistentry>
 664                         <varlistentry>
 665                                 <term><command>reset-failed [NAME...]</command></term>
 666
 667                                 <listitem><para>Reset the
 668                                 '<literal>failed</literal>' state of the
 669                                 specified units, or if no unit name is
 670                                 passed of all units. When a unit fails
 671                                 in some way (i.e. process exiting with
 672                                 non-zero error code, terminating
 673                                 abnormally or timing out) it will
 674                                 automatically enter the
 675                                 '<literal>failed</literal>' state and
 676                                 its exit code and status is recorded
 677                                 for introspection by the administrator
 678                                 until the service is restarted or
 679                                 reset with this
 680                                 command.</para></listitem>
 681                         </varlistentry>
 682
 683                         <varlistentry>
 684                                 <term><command>list-unit-files</command></term>
 685
 686                                 <listitem><para>List installed unit files.
 687                                 </para></listitem>
 688                         </varlistentry>
 689
 690                         <varlistentry>
 691                                 <term><command>enable [NAME...]</command></term>
 692
 693                                 <listitem><para>Enable one or
 694                                 more unit files or unit file
 695                                 instances, as specified on the
 696                                 command line. This will create a
 697                                 number of symlinks as encoded in
 698                                 the <literal>[Install]</literal>
 699                                 sections of the unit files. After
 700                                 the symlinks have been created the
 701                                 systemd configuration is reloaded
 702                                 (in a way that is equivalent to
 703                                 <command>daemon-reload</command>)
 704                                 to ensure the changes are taken into
 705                                 account immediately. Note that this
 706                                 does not have the effect that any of
 707                                 the units enabled are also started at
 708                                 the same time.  If this is desired
 709                                 a separate <command>start</command>
 710                                 command must be invoked for the unit.
 711                                 Also note that in case of instance
 712                                 enablement, symlinks named same as
 713                                 instances are created in install
 714                                 location, however they all point to
 715                                 the same template unit file.</para>
 716
 717                                 <para>This command will
 718                                 print the actions executed. This
 719                                 output may be suppressed by passing
 720                                 <option>--quiet</option>.</para>
 721
 722                                 <para>Note that this operation creates
 723                                 only the suggested symlinks for the
 724                                 units. While this command is the
 725                                 recommended way to manipulate the unit
 726                                 configuration directory, the
 727                                 administrator is free to make
 728                                 additional changes manually, by
 729                                 placing or removing symlinks in the
 730                                 directory. This is particularly useful
 731                                 to create configurations that deviate
 732                                 from the suggested default
 733                                 installation. In this case the
 734                                 administrator must make sure to invoke
 735                                 <command>daemon-reload</command>
 736                                 manually as necessary, to ensure his
 737                                 changes are taken into account.</para>
 738
 739                                 <para>Enabling units should not be
 740                                 confused with starting (activating)
 741                                 units, as done by the
 742                                 <command>start</command>
 743                                 command. Enabling and starting units
 744                                 is orthogonal: units may be enabled
 745                                 without being started and started
 746                                 without being enabled. Enabling simply
 747                                 hooks the unit into various suggested
 748                                 places (for example, so that the unit
 749                                 is automatically started on boot or
 750                                 when a particular kind of hardware is
 751                                 plugged in). Starting actually spawns
 752                                 the daemon process (in case of service
 753                                 units), or binds the socket (in case
 754                                 of socket units), and so
 755                                 on.</para>
 756
 757                                 <para>Depending on whether
 758                                 <option>--system</option>,
 759                                 <option>--user</option> or
 760                                 <option>--global</option> is specified
 761                                 this enables the unit for the system,
 762                                 for the calling user only
 763                                 or for all future logins of all
 764                                 users. Note that in the latter case no
 765                                 systemd daemon configuration is
 766                                 reloaded.</para>
 767                                 </listitem>
 768                         </varlistentry>
 769
 770                         <varlistentry>
 771                                 <term><command>disable [NAME...]</command></term>
 772
 773                                 <listitem><para>Disables one or more
 774                                 units. This removes all symlinks to
 775                                 the specified unit files from the unit
 776                                 configuration directory, and hence
 777                                 undoes the changes made by
 778                                 <command>enable</command>. Note
 779                                 however that this removes
 780                                 all symlinks to the unit files
 781                                 (i.e. including manual additions), not
 782                                 just those actually created by
 783                                 <command>enable</command>. This call
 784                                 implicitly reloads the systemd daemon
 785                                 configuration after completing the
 786                                 disabling of the units. Note that this
 787                                 command does not implicitly stop the
 788                                 units that are being disabled. If this
 789                                 is desired an additional
 790                                 <command>stop</command> command should
 791                                 be executed afterwards.</para>
 792
 793                                 <para>This command will print the
 794                                 actions executed. This output may be
 795                                 suppressed by passing
 796                                 <option>--quiet</option>.</para>
 797                                 </listitem>
 798
 799                                 <para>This command honors
 800                                 <option>--system</option>,
 801                                 <option>--user</option>,
 802                                 <option>--global</option> in a similar
 803                                 way as
 804                                 <command>enable</command>.</para>
 805                         </varlistentry>
 806
 807                         <varlistentry>
 808                                 <term><command>is-enabled [NAME...]</command></term>
 809
 810                                 <listitem><para>Checks whether any of
 811                                 the specified unit files are enabled
 812                                 (as with
 813                                 <command>enable</command>). Returns an
 814                                 exit code of 0 if at least one is
 815                                 enabled, non-zero otherwise. Prints
 816                                 the current enable status. To suppress
 817                                 this output use
 818                                 <option>--quiet</option>.</para></listitem>
 819                         </varlistentry>
 820
 821                         <varlistentry>
 822                                 <term><command>reenable [NAME...]</command></term>
 823
 824                                 <listitem><para>Reenable one or more
 825                                 unit files, as specified on the
 826                                 command line. This is a combination of
 827                                 <command>disable</command> and
 828                                 <command>enable</command> and is
 829                                 useful to reset the symlinks a unit is
 830                                 enabled with to the defaults
 831                                 configured in the
 832                                 <literal>[Install]</literal> section
 833                                 of the unit file.</para>
 834                                 </listitem>
 835                         </varlistentry>
 836
 837                         <varlistentry>
 838                                 <term><command>preset [NAME...]</command></term>
 839
 840                                 <listitem><para>Reset one or more unit
 841                                 files, as specified on the command
 842                                 line, to the defaults configured in
 843                                 the preset policy files. This has the
 844                                 same effect as
 845                                 <command>disable</command> or
 846                                 <command>enable</command>, depending
 847                                 how the unit is listed in the preset
 848                                 files. For more information on preset
 849                                 policy format see
 850                                 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 851                                 more information on the concept of
 852                                 presets please consult the <ulink
 853                                 url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
 854                                 document.</para>
 855                                 </listitem>
 856                         </varlistentry>
 857
 858                         <varlistentry>
 859                                 <term><command>mask [NAME...]</command></term>
 860
 861                                 <listitem><para>Mask one or more unit
 862                                 files, as specified on the command
 863                                 line. This will link these units to
 864                                 <filename>/dev/null</filename>, making
 865                                 it impossible to start them. This is a stronger version
 866                                 of <command>disable</command>, since
 867                                 it prohibits all kinds of activation
 868                                 of the unit, including manual
 869                                 activation. Use this option with
 870                                 care.</para>
 871                                 </listitem>
 872                         </varlistentry>
 873
 874                         <varlistentry>
 875                                 <term><command>unmask [NAME...]</command></term>
 876
 877                                 <listitem><para>Unmask one or more
 878                                 unit files, as specified on the
 879                                 command line. This will undo the
 880                                 effect of
 881                                 <command>mask</command>.</para>
 882                                 </listitem>
 883                         </varlistentry>
 884
 885                         <varlistentry>
 886                                 <term><command>link [NAME...]</command></term>
 887
 888                                 <listitem><para>Link a unit file that
 889                                 is not in the unit file search paths
 890                                 into the unit file search path. This
 891                                 requires an absolute path to a unit
 892                                 file. The effect of this can be undone
 893                                 with <command>disable</command>. The
 894                                 effect of this command is that a unit
 895                                 file is available for
 896                                 <command>start</command> and other
 897                                 commands although it isn't installed
 898                                 directly in the unit search
 899                                 path.</para>
 900                                 </listitem>
 901                         </varlistentry>
 902
 903                         <varlistentry>
 904                                 <term><command>load [NAME...]</command></term>
 905
 906                                 <listitem><para>Load one or more units
 907                                 specified on the command line. This
 908                                 will simply load their configuration
 909                                 from disk, but not start them. To
 910                                 start them you need to use the
 911                                 <command>start</command> command which
 912                                 will implicitly load a unit that has
 913                                 not been loaded yet. Note that systemd
 914                                 garbage collects loaded units that are
 915                                 not active or referenced by an active
 916                                 unit. This means that units loaded
 917                                 this way will usually not stay loaded
 918                                 for long. Also note that this command
 919                                 cannot be used to reload unit
 920                                 configuration. Use the
 921                                 <command>daemon-reload</command>
 922                                 command for that. All in all, this
 923                                 command is of little use except for
 924                                 debugging.</para>
 925                                 <para>This command should not be
 926                                 confused with the
 927                                 <command>daemon-reload</command> or
 928                                 <command>reload</command>
 929                                 commands.</para></listitem>
 930                         </varlistentry>
 931                         <varlistentry>
 932                                 <term><command>list-jobs</command></term>
 933
 934                                 <listitem><para>List jobs that are in progress.</para></listitem>
 935                         </varlistentry>
 936                         <varlistentry>
 937                                 <term><command>cancel [JOB...]</command></term>
 938
 939                                 <listitem><para>Cancel one or more
 940                                 jobs specified on the command line by
 941                                 their numeric job
 942                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 943                         </varlistentry>
 944                         <varlistentry>
 945                                 <term><command>dump</command></term>
 946
 947                                 <listitem><para>Dump server
 948                                 status. This will output a (usually
 949                                 very long) human readable manager
 950                                 status dump. Its format is subject to
 951                                 change without notice and should not
 952                                 be parsed by
 953                                 applications.</para></listitem>
 954                         </varlistentry>
 955                         <varlistentry>
 956                                 <term><command>list-dependencies [NAME]</command></term>
 957
 958                                 <listitem><para> Shows required and
 959                                 wanted units of the specified unit. If
 960                                 no unit is specified
 961                                 <filename>default.target</filename> is
 962                                 implied. Target units are recursively
 963                                 expanded.  When <option>--all</option>
 964                                 is passed all other units aare
 965                                 recursively expanded as well.</para>
 966                                 </listitem>
 967                         </varlistentry>
 968                         <varlistentry>
 969                                 <term><command>snapshot [NAME]</command></term>
 970
 971                                 <listitem><para>Create a snapshot. If
 972                                 a snapshot name is specified, the new
 973                                 snapshot will be named after it. If
 974                                 none is specified an automatic
 975                                 snapshot name is generated. In either
 976                                 case, the snapshot name used is
 977                                 printed to STDOUT, unless
 978                                 <option>--quiet</option> is
 979                                 specified.</para>
 980
 981                                 <para>A snapshot refers to a saved
 982                                 state of the systemd manager. It is
 983                                 implemented itself as a unit that is
 984                                 generated dynamically with this
 985                                 command and has dependencies on all
 986                                 units active at the time. At a later
 987                                 time the user may return to this state
 988                                 by using the
 989                                 <command>isolate</command> command on
 990                                 the snapshot unit.</para></listitem>
 991
 992                                 <para>Snapshots are only useful for
 993                                 saving and restoring which units are
 994                                 running or are stopped, they do not
 995                                 save/restore any other
 996                                 state. Snapshots are dynamic and lost
 997                                 on reboot.</para>
 998                         </varlistentry>
 999                         <varlistentry>
1000                                 <term><command>delete [NAME...]</command></term>
1001
1002                                 <listitem><para>Remove a snapshot
1003                                 previously created with
1004                                 <command>snapshot</command>.</para></listitem>
1005                         </varlistentry>
1006                         <varlistentry>
1007                                 <term><command>daemon-reload</command></term>
1008
1009                                 <listitem><para>Reload systemd manager
1010                                 configuration. This will reload all
1011                                 unit files and recreate the entire
1012                                 dependency tree. While the daemon is
1013                                 reloaded, all sockets systemd listens
1014                                 on on behalf of user configuration will
1015                                 stay accessible.</para> <para>This
1016                                 command should not be confused with
1017                                 the <command>load</command> or
1018                                 <command>reload</command>
1019                                 commands.</para></listitem>
1020                         </varlistentry>
1021                         <varlistentry>
1022                                 <term><command>daemon-reexec</command></term>
1023
1024                                 <listitem><para>Reexecute the systemd
1025                                 manager. This will serialize the
1026                                 manager state, reexecute the process
1027                                 and deserialize the state again. This
1028                                 command is of little use except for
1029                                 debugging and package
1030                                 upgrades. Sometimes it might be
1031                                 helpful as a heavy-weight
1032                                 <command>daemon-reload</command>. While
1033                                 the daemon is reexecuted all sockets
1034                                 systemd listens on on behalf of user
1035                                 configuration will stay
1036                                 accessible.</para></listitem>
1037                         </varlistentry>
1038                         <varlistentry>
1039                                 <term><command>show-environment</command></term>
1040
1041                                 <listitem><para>Dump the systemd
1042                                 manager environment block. The
1043                                 environment block will be dumped in
1044                                 straight-forward form suitable for
1045                                 sourcing into a shell script. This
1046                                 environment block will be passed to
1047                                 all processes the manager
1048                                 spawns.</para></listitem>
1049                         </varlistentry>
1050                         <varlistentry>
1051                                 <term><command>set-environment [NAME=VALUE...]</command></term>
1052
1053                                 <listitem><para>Set one or more
1054                                 systemd manager environment variables,
1055                                 as specified on the command
1056                                 line.</para></listitem>
1057                         </varlistentry>
1058                         <varlistentry>
1059                                 <term><command>unset-environment [NAME...]</command></term>
1060
1061                                 <listitem><para>Unset one or more
1062                                 systemd manager environment
1063                                 variables. If only a variable name is
1064                                 specified it will be removed
1065                                 regardless of its value. If a variable
1066                                 and a value are specified the variable
1067                                 is only removed if it has the
1068                                 specified value.</para></listitem>
1069                         </varlistentry>
1070                         <varlistentry>
1071                                 <term><command>default</command></term>
1072
1073                                 <listitem><para>Enter default
1074                                 mode. This is mostly equivalent to
1075                                 <command>start
1076                                 default.target</command>.</para></listitem>
1077                         </varlistentry>
1078                         <varlistentry>
1079                                 <term><command>rescue</command></term>
1080
1081                                 <listitem><para>Enter rescue
1082                                 mode. This is mostly equivalent to
1083                                 <command>isolate
1084                                 rescue.target</command> but also
1085                                 prints a wall message to all
1086                                 users.</para></listitem>
1087                         </varlistentry>
1088                         <varlistentry>
1089                                 <term><command>emergency</command></term>
1090
1091                                 <listitem><para>Enter emergency
1092                                 mode. This is mostly equivalent to
1093                                 <command>isolate
1094                                 emergency.target</command> but also
1095                                 prints a wall message to all
1096                                 users.</para></listitem>
1097                         </varlistentry>
1098                         <varlistentry>
1099                                 <term><command>halt</command></term>
1100
1101                                 <listitem><para>Shut down and halt the
1102                                 system. This is mostly equivalent to
1103                                 <command>start halt.target</command>
1104                                 but also prints a wall message to all
1105                                 users.  If combined with
1106                                 <option>--force</option> shutdown of
1107                                 all running services is skipped,
1108                                 however all processes are killed and
1109                                 all file systems are unmounted or
1110                                 mounted read-only, immediately
1111                                 followed by the system halt.  If
1112                                 <option>--force</option> is specified
1113                                 twice the operation is immediately
1114                                 executed without terminating any
1115                                 processes or unmounting any file
1116                                 systems. This may result in data
1117                                 loss.</para></listitem>
1118                         </varlistentry>
1119                         <varlistentry>
1120                                 <term><command>poweroff</command></term>
1121
1122                                 <listitem><para>Shut down and
1123                                 power-off the system. This is mostly
1124                                 equivalent to <command>start
1125                                 poweroff.target</command> but also
1126                                 prints a wall message to all users. If
1127                                 combined with <option>--force</option>
1128                                 shutdown of all running services is
1129                                 skipped, however all processes are
1130                                 killed and all file systems are
1131                                 unmounted or mounted read-only,
1132                                 immediately followed by the powering
1133                                 off. If <option>--force</option> is
1134                                 specified twice the operation is
1135                                 immediately executed without
1136                                 terminating any processes or
1137                                 unmounting any file systems. This may
1138                                 result in data loss.</para></listitem>
1139                         </varlistentry>
1140                         <varlistentry>
1141                                 <term><command>reboot</command></term>
1142
1143                                 <listitem><para>Shut down and reboot
1144                                 the system. This is mostly equivalent
1145                                 to <command>start
1146                                 reboot.target</command> but also
1147                                 prints a wall message to all users. If
1148                                 combined with <option>--force</option>
1149                                 shutdown of all running services is
1150                                 skipped, however all processes are
1151                                 killed and all file systems are
1152                                 unmounted or mounted read-only,
1153                                 immediately followed by the reboot. If
1154                                 <option>--force</option> is specified
1155                                 twice the operation is immediately
1156                                 executed without terminating any
1157                                 processes or unmounting any file
1158                                 systems. This may result in data
1159                                 loss.</para></listitem>
1160                         </varlistentry>
1161                         <varlistentry>
1162                                 <term><command>kexec</command></term>
1163
1164                                 <listitem><para>Shut down and reboot
1165                                 the system via kexec. This is mostly
1166                                 equivalent to <command>start
1167                                 kexec.target</command> but also prints
1168                                 a wall message to all users. If
1169                                 combined with <option>--force</option>
1170                                 shutdown of all running services is
1171                                 skipped, however all processes are killed
1172                                 and all file systems are unmounted or
1173                                 mounted read-only, immediately
1174                                 followed by the
1175                                 reboot.</para></listitem>
1176                         </varlistentry>
1177                         <varlistentry>
1178                                 <term><command>exit</command></term>
1179
1180                                 <listitem><para>Ask the systemd
1181                                 manager to quit. This is only
1182                                 supported for user service managers
1183                                 (i.e. in conjunction with the
1184                                 <option>--user</option> option) and
1185                                 will fail otherwise.</para></listitem>
1186                         </varlistentry>
1187                         <varlistentry>
1188                                 <term><command>suspend</command></term>
1189
1190                                 <listitem><para>Suspend the
1191                                 system. This will trigger activation
1192                                 of the special
1193                                 <filename>suspend.target</filename>
1194                                 target.</para></listitem>
1195                         </varlistentry>
1196                         <varlistentry>
1197                                 <term><command>hibernate</command></term>
1198
1199                                 <listitem><para>Hibernate the
1200                                 system. This will trigger activation
1201                                 of the special
1202                                 <filename>hibernate.target</filename>
1203                                 target.</para></listitem>
1204                         </varlistentry>
1205                         <varlistentry>
1206                                 <term><command>hybrid-sleep</command></term>
1207
1208                                 <listitem><para>Hibernate and suspend
1209                                 the system. This will trigger
1210                                 activation of the special
1211                                 <filename>hybrid-sleep.target</filename>
1212                                 target.</para></listitem>
1213                         </varlistentry>
1214                         <varlistentry>
1215                                 <term><command>switch-root [ROOT] [INIT]</command></term>
1216
1217                                 <listitem><para>Switches to a
1218                                 different root directory and executes
1219                                 a new system manager process below
1220                                 it. This is intended for usage in
1221                                 initial RAM disks ("initrd"), and will
1222                                 transition from the initrd's system
1223                                 manager process (a.k.a "init" process)
1224                                 to the main system manager
1225                                 process. Takes two arguments: the
1226                                 directory to make the new root
1227                                 directory, and the path to the new
1228                                 system manager binary below it to
1229                                 execute as PID 1. If the latter is
1230                                 omitted or the empty string, a
1231                                 systemd binary will automatically be
1232                                 searched for and used as init. If the
1233                                 system manager path is omitted or
1234                                 equal the empty string the state of
1235                                 the initrd's system manager process is
1236                                 passed to the main system manager,
1237                                 which allows later introspection of the
1238                                 state of the services involved in the
1239                                 initrd boot.</para></listitem>
1240                         </varlistentry>
1241                 </variablelist>
1242
1243         </refsect1>
1244
1245         <refsect1>
1246                 <title>Exit status</title>
1247
1248                 <para>On success 0 is returned, a non-zero failure
1249                 code otherwise.</para>
1250         </refsect1>
1251
1252         <refsect1>
1253                 <title>Environment</title>
1254
1255                 <variablelist class='environment-variables'>
1256                         <varlistentry>
1257                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1258                                 <listitem><para>Pager to use when
1259                                 <option>--no-pager</option> is not given;
1260                                 overrides <varname>$PAGER</varname>.  Setting
1261                                 this to an empty string or the value
1262                                 <literal>cat</literal> is equivalent to passing
1263                                 <option>--no-pager</option>.</para></listitem>
1264                         </varlistentry>
1265                 </variablelist>
1266         </refsect1>
1267
1268         <refsect1>
1269                 <title>See Also</title>
1270                 <para>
1271                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1272                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1273                         <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1274                         <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1275                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1276                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1277                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1278                         <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1279                 </para>
1280         </refsect1>
1281
1282 </refentry>