man/systemd.service.xml

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   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
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  12   under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2 of the License, or
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  24
  25 <refentry id="systemd.service">
  26         <refentryinfo>
  27                 <title>systemd.service</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>systemd.service</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.service</refname>
  47                 <refpurpose>systemd service configuration files</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename></para>
  52         </refsynopsisdiv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  57                 <para>A unit configuration file whose name ends in
  58                 <filename>.service</filename> encodes information
  59                 about a process controlled and supervised by
  60                 systemd.</para>
  61
  62                 <para>This man page lists the configuration options
  63                 specific to this unit type. See
  64                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  65                 for the common options of all unit configuration
  66                 files. The common configuration items are configured
  67                 in the generic <literal>[Unit]</literal> and
  68                 <literal>[Install]</literal> sections. The service
  69                 specific configuration options are configured in the
  70                 <literal>[Service]</literal> section.</para>
  71
  72                 <para>Additional options are listed in
  73                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  74                 which define the execution environment the commands
  75                 are executed in.</para>
  76
  77                 <para>Unless <varname>DefaultDependencies=</varname>
  78                 is set to <option>false</option>, service units will
  79                 implicitly have dependencies of type
  80                 <varname>Requires=</varname> and
  81                 <varname>After=</varname> on
  82                 <filename>basic.target</filename> as well as
  83                 dependencies of type <varname>Conflicts=</varname> and
  84                 <varname>Before=</varname> on
  85                 <filename>shutdown.target</filename>. These ensure
  86                 that normal service units pull in basic system
  87                 initialization, and are terminated cleanly prior to
  88                 system shutdown. Only services involved with early
  89                 boot or late system shutdown should disable this
  90                 option.</para>
  91
  92                 <para>If a service is requested under a certain name
  93                 but no unit configuration file is found, systemd looks
  94                 for a SysV init script by the same name (with the
  95                 <filename>.service</filename> suffix removed) and
  96                 dynamically creates a service unit from that
  97                 script. This is useful for compatibility with
  98                 SysV.</para>
  99         </refsect1>
 100
 101         <refsect1>
 102                 <title>Options</title>
 103
 104                 <para>Service files must include a
 105                 <literal>[Service]</literal> section, which carries
 106                 information about the service and the process it
 107                 supervises. A number of options that may be used in
 108                 this section are shared with other unit types. These
 109                 options are documented in
 110                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
 111                 options specific to the <literal>[Service]</literal>
 112                 section of service units are the following:</para>
 113
 114                 <variablelist>
 115                         <varlistentry>
 116                                 <term><varname>Type=</varname></term>
 117
 118                                 <listitem><para>Configures the process
 119                                 start-up type for this service
 120                                 unit. One of <option>simple</option>,
 121                                 <option>forking</option>,
 122                                 <option>oneshot</option>,
 123                                 <option>dbus</option>,
 124                                 <option>notify</option>.</para>
 125
 126                                 <para>If set to
 127                                 <option>simple</option> (the default
 128                                 value) it is expected that the process
 129                                 configured with
 130                                 <varname>ExecStart=</varname> is the
 131                                 main process of the service. In this
 132                                 mode, if the process offers
 133                                 functionality to other processes on
 134                                 the system its communication channels
 135                                 should be installed before the daemon
 136                                 is started up (e.g. sockets set up by
 137                                 systemd, via socket activation), as
 138                                 systemd will immediately proceed
 139                                 starting follow-up units.</para>
 140
 141                                 <para>If set to
 142                                 <option>forking</option> it is
 143                                 expected that the process configured
 144                                 with <varname>ExecStart=</varname>
 145                                 will call <function>fork()</function>
 146                                 as part of its start-up. The parent process is
 147                                 expected to exit when start-up is
 148                                 complete and all communication
 149                                 channels set up. The child continues
 150                                 to run as the main daemon
 151                                 process. This is the behaviour of
 152                                 traditional UNIX daemons. If this
 153                                 setting is used, it is recommended to
 154                                 also use the
 155                                 <varname>PIDFile=</varname> option, so
 156                                 that systemd can identify the main
 157                                 process of the daemon. systemd will
 158                                 proceed starting follow-up units as
 159                                 soon as the parent process
 160                                 exits.</para>
 161
 162                                 <para>Behaviour of
 163                                 <option>oneshot</option> is similar
 164                                 to <option>simple</option>, however
 165                                 it is expected that the process has to
 166                                 exit before systemd starts follow-up
 167                                 units. <varname>RemainAfterExit=</varname>
 168                                 is particularly useful for this type
 169                                 of service.</para>
 170
 171                                 <para>Behaviour of
 172                                 <option>dbus</option> is similar to
 173                                 <option>simple</option>, however it is
 174                                 expected that the daemon acquires a
 175                                 name on the D-Bus bus, as configured
 176                                 by
 177                                 <varname>BusName=</varname>. systemd
 178                                 will proceed starting follow-up units
 179                                 after the D-Bus bus name has been
 180                                 acquired. Service units with this
 181                                 option configured implicitly gain
 182                                 dependencies on the
 183                                 <filename>dbus.socket</filename>
 184                                 unit.</para>
 185
 186                                 <para>Behaviour of
 187                                 <option>notify</option> is similar to
 188                                 <option>simple</option>, however it is
 189                                 expected that the daemon sends a
 190                                 notification message via
 191                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 192                                 or an equivalent call when it finished
 193                                 starting up. systemd will proceed
 194                                 starting follow-up units after this
 195                                 notification message has been sent. If
 196                                 this option is used
 197                                 <varname>NotifyAccess=</varname> (see
 198                                 below) should be set to open access to
 199                                 the notification socket provided by
 200                                 systemd. If
 201                                 <varname>NotifyAccess=</varname> is not
 202                                 set, it will implicitly be set to
 203                                 <option>main</option>.</para>
 204                                 </listitem>
 205                         </varlistentry>
 206
 207                         <varlistentry>
 208                                 <term><varname>RemainAfterExit=</varname></term>
 209
 210                                 <listitem><para>Takes a boolean value
 211                                 that specifies whether the service
 212                                 shall be considered active even when
 213                                 all its processes exited. Defaults to
 214                                 <option>no</option>.</para>
 215                                 </listitem>
 216                         </varlistentry>
 217
 218                         <varlistentry>
 219                                 <term><varname>GuessMainPID=</varname></term>
 220
 221                                 <listitem><para>Takes a boolean value
 222                                 that specifies whether systemd should
 223                                 try to guess the main PID of a service
 224                                 should if it cannot be determined
 225                                 reliably. This option is ignored
 226                                 unless <option>Type=forking</option>
 227                                 is set and <option>PIDFile=</option>
 228                                 is unset because for the other types
 229                                 or with an explicitly configured PID
 230                                 file the main PID is always known. The
 231                                 guessing algorithm might come to
 232                                 incorrect conclusions if a daemon
 233                                 consists of more than one process. If
 234                                 the main PID cannot be determined
 235                                 failure detection and automatic
 236                                 restarting of a service will not work
 237                                 reliably. Defaults to
 238                                 <option>yes</option>.</para>
 239                                 </listitem>
 240                         </varlistentry>
 241
 242                         <varlistentry>
 243                                 <term><varname>PIDFile=</varname></term>
 244
 245                                 <listitem><para>Takes an absolute file
 246                                 name pointing to the PID file of this
 247                                 daemon. Use of this option is
 248                                 recommended for services where
 249                                 <varname>Type=</varname> is set to
 250                                 <option>forking</option>. systemd will
 251                                 read the PID of the main process of
 252                                 the daemon after start-up of the
 253                                 service. systemd will not write to the
 254                                 file configured here.</para>
 255                                 </listitem>
 256                         </varlistentry>
 257
 258                         <varlistentry>
 259                                 <term><varname>BusName=</varname></term>
 260
 261                                 <listitem><para>Takes a D-Bus bus
 262                                 name, where this service is reachable
 263                                 as. This option is mandatory for
 264                                 services where
 265                                 <varname>Type=</varname> is set to
 266                                 <option>dbus</option>, but its use
 267                                 is otherwise recommended as well if
 268                                 the process takes a name on the D-Bus
 269                                 bus.</para>
 270                                 </listitem>
 271                         </varlistentry>
 272
 273                         <varlistentry>
 274                                 <term><varname>ExecStart=</varname></term>
 275                                 <listitem><para>Takes a command line
 276                                 that is executed when this service
 277                                 shall be started up. The first token
 278                                 of the command line must be an
 279                                 absolute file name, then followed by
 280                                 arguments for the process. It is
 281                                 mandatory to set this option for all
 282                                 services. This option may not be
 283                                 specified more than once, except when
 284                                 <varname>Type=oneshot</varname> is
 285                                 used in which case more than one
 286                                 <varname>ExecStart=</varname> line is
 287                                 accepted which are then invoked one by
 288                                 one, sequentially in the order they
 289                                 appear in the unit file.</para>
 290
 291                                 <para>Optionally, if the absolute file
 292                                 name is prefixed with
 293                                 <literal>@</literal>, the second token
 294                                 will be passed as
 295                                 <literal>argv[0]</literal> to the
 296                                 executed process, followed by the
 297                                 further arguments specified. If the
 298                                 first token is prefixed with
 299                                 <literal>-</literal> an exit code of
 300                                 the command normally considered a
 301                                 failure (i.e. non-zero exit status or
 302                                 abnormal exit due to signal) is ignored
 303                                 and considered success. If both
 304                                 <literal>-</literal> and
 305                                 <literal>@</literal> are used for the
 306                                 same command the former must precede
 307                                 the latter. Unless
 308                                 <varname>Type=forking</varname> is
 309                                 set, the process started via this
 310                                 command line will be considered the
 311                                 main process of the daemon. The
 312                                 command line accepts % specifiers as
 313                                 described in
 314                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 315
 316                                 <para>On top of that basic environment
 317                                 variable substitution is
 318                                 supported. Use
 319                                 <literal>${FOO}</literal> as part of a
 320                                 word, or as word of its own on the
 321                                 command line, in which case it will be
 322                                 replaced by the value of the
 323                                 environment variable including all
 324                                 whitespace it contains, resulting in a
 325                                 single argument.  Use
 326                                 <literal>$FOO</literal> as a separate
 327                                 word on the command line, in which
 328                                 case it will be replaced by the value
 329                                 of the environment variable split up
 330                                 at whitespace, resulting in no or more
 331                                 arguments. Note that the first
 332                                 argument (i.e. the program to execute)
 333                                 may not be a variable, and must be a
 334                                 literal and absolute path
 335                                 name.</para></listitem>
 336                         </varlistentry>
 337
 338                         <varlistentry>
 339                                 <term><varname>ExecStartPre=</varname></term>
 340                                 <term><varname>ExecStartPost=</varname></term>
 341                                 <listitem><para>Additional commands
 342                                 that are executed before (resp. after)
 343                                 the command in
 344                                 <varname>ExecStart=</varname>. Multiple
 345                                 command lines may be concatenated in a
 346                                 single directive, by separating them
 347                                 by semicolons (these semicolons must
 348                                 be passed as separate words). In that
 349                                 case, the commands are executed one
 350                                 after the other,
 351                                 serially. Alternatively, these
 352                                 directives may be specified more than
 353                                 once with the same effect. However,
 354                                 the latter syntax is not recommended
 355                                 for compatibility with parsers
 356                                 suitable for XDG
 357                                 <filename>.desktop</filename> files.
 358                                 Use of these settings is
 359                                 optional. Specifier and environment
 360                                 variable substitution is
 361                                 supported.</para></listitem>
 362                         </varlistentry>
 363
 364                         <varlistentry>
 365                                 <term><varname>ExecReload=</varname></term>
 366                                 <listitem><para>Commands to execute to
 367                                 trigger a configuration reload in the
 368                                 service. This argument takes multiple
 369                                 command lines, following the same
 370                                 scheme as pointed out for
 371                                 <varname>ExecStartPre=</varname>
 372                                 above. Use of this setting is
 373                                 optional. Specifier and environment
 374                                 variable substitution is supported
 375                                 here following the same scheme as for
 376                                 <varname>ExecStart=</varname>. One
 377                                 special environment variable is set:
 378                                 if known <literal>$MAINPID</literal> is
 379                                 set to the main process of the
 380                                 daemon, and may be used for command
 381                                 lines like the following:
 382                                 <command>/bin/kill -HUP
 383                                 $MAINPID</command>.</para></listitem>
 384                         </varlistentry>
 385
 386                         <varlistentry>
 387                                 <term><varname>ExecStop=</varname></term>
 388                                 <listitem><para>Commands to execute to
 389                                 stop the service started via
 390                                 <varname>ExecStart=</varname>. This
 391                                 argument takes multiple command lines,
 392                                 following the same scheme as pointed
 393                                 out for
 394                                 <varname>ExecStartPre=</varname>
 395                                 above. Use of this setting is
 396                                 optional. All processes remaining for
 397                                 a service after the commands
 398                                 configured in this option are run are
 399                                 terminated according to the
 400                                 <varname>KillMode=</varname> setting
 401                                 (see below). If this option is not
 402                                 specified the process is terminated
 403                                 right-away when service stop is
 404                                 requested. Specifier and environment
 405                                 variable substitution is supported
 406                                 (including
 407                                 <literal>$MAINPID</literal>, see
 408                                 above).</para></listitem>
 409                         </varlistentry>
 410
 411                         <varlistentry>
 412                                 <term><varname>ExecStopPost=</varname></term>
 413                                 <listitem><para>Additional commands
 414                                 that are executed after the service
 415                                 was stopped using the commands
 416                                 configured in
 417                                 <varname>ExecStop=</varname>. This
 418                                 argument takes multiple command lines,
 419                                 following the same scheme as pointed
 420                                 out for
 421                                 <varname>ExecStartPre</varname>. Use
 422                                 of these settings is
 423                                 optional. Specifier and environment
 424                                 variable substitution is
 425                                 supported.</para></listitem>
 426                         </varlistentry>
 427
 428                         <varlistentry>
 429                                 <term><varname>RestartSec=</varname></term>
 430                                 <listitem><para>Configures the time to
 431                                 sleep before restarting a service (as
 432                                 configured with
 433                                 <varname>Restart=</varname>). Takes a
 434                                 unit-less value in seconds, or a time
 435                                 span value such as "5min
 436                                 20s". Defaults to
 437                                 100ms.</para></listitem>
 438                         </varlistentry>
 439
 440                         <varlistentry>
 441                                 <term><varname>TimeoutSec=</varname></term>
 442                                 <listitem><para>Configures the time to
 443                                 wait for start-up and stop. If a
 444                                 daemon service does not signal
 445                                 start-up completion within the
 446                                 configured time the service will be
 447                                 considered failed and be shut down
 448                                 again. If a service is asked to stop
 449                                 but does not terminate in the
 450                                 specified time it will be terminated
 451                                 forcibly via SIGTERM, and after
 452                                 another delay of this time with
 453                                 SIGKILL. (See
 454                                 <varname>KillMode=</varname>
 455                                 below.) Takes a unit-less value in seconds, or a
 456                                 time span value such as "5min
 457                                 20s". Pass 0 to disable the timeout
 458                                 logic. Defaults to
 459                                 90s.</para></listitem>
 460                         </varlistentry>
 461
 462                         <varlistentry>
 463                                 <term><varname>Restart=</varname></term>
 464                                 <listitem><para>Configures whether the
 465                                 main service process shall be
 466                                 restarted when it exits. Takes one of
 467                                 <option>no</option>,
 468                                 <option>on-success</option>,
 469                                 <option>on-failure</option>,
 470                                 <option>on-abort</option> or
 471                                 <option>always</option>. If set to
 472                                 <option>no</option> (the default) the
 473                                 service will not be restarted when it
 474                                 exits. If set to
 475                                 <option>on-success</option> it will be
 476                                 restarted only when it exited cleanly,
 477                                 i.e. terminated with an exit code of
 478                                 0. If set to
 479                                 <option>on-failure</option> it will be
 480                                 restarted only when it exited with an
 481                                 exit code not equalling 0, or when
 482                                 terminated by a signal. If set to
 483                                 <option>on-abort</option> it will be
 484                                 restarted only if it exits due to
 485                                 reception of an uncaught signal. If
 486                                 set to <option>always</option> the
 487                                 service will be restarted regardless
 488                                 whether it exited cleanly or not, or
 489                                 got terminated abnormally by a
 490                                 signal.</para></listitem>
 491                         </varlistentry>
 492
 493                         <varlistentry>
 494                                 <term><varname>PermissionsStartOnly=</varname></term>
 495                                 <listitem><para>Takes a boolean
 496                                 argument. If true, the permission
 497                                 related execution options as
 498                                 configured with
 499                                 <varname>User=</varname> and similar
 500                                 options (see
 501                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 502                                 for more information) are only applied
 503                                 to the process started with
 504                                 <varname>ExecStart=</varname>, and not
 505                                 to the various other
 506                                 <varname>ExecStartPre=</varname>,
 507                                 <varname>ExecStartPost=</varname>,
 508                                 <varname>ExecReload=</varname>,
 509                                 <varname>ExecStop=</varname>,
 510                                 <varname>ExecStopPost=</varname>
 511                                 commands. If false, the setting is
 512                                 applied to all configured commands the
 513                                 same way. Defaults to
 514                                 false.</para></listitem>
 515                         </varlistentry>
 516
 517                         <varlistentry>
 518                                 <term><varname>RootDirectoryStartOnly=</varname></term>
 519                                 <listitem><para>Takes a boolean
 520                                 argument. If true, the root directory
 521                                 as configured with the
 522                                 <varname>RootDirectory=</varname>
 523                                 option (see
 524                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 525                                 for more information) is only applied
 526                                 to the process started with
 527                                 <varname>ExecStart=</varname>, and not
 528                                 to the various other
 529                                 <varname>ExecStartPre=</varname>,
 530                                 <varname>ExecStartPost=</varname>,
 531                                 <varname>ExecReload=</varname>,
 532                                 <varname>ExecStop=</varname>,
 533                                 <varname>ExecStopPost=</varname>
 534                                 commands. If false, the setting is
 535                                 applied to all configured commands the
 536                                 same way. Defaults to
 537                                 false.</para></listitem>
 538                         </varlistentry>
 539
 540                         <varlistentry>
 541                                 <term><varname>SysVStartPriority=</varname></term>
 542                                 <listitem><para>Set the SysV start
 543                                 priority to use to order this service
 544                                 in relation to SysV services lacking
 545                                 LSB headers. This option is only
 546                                 necessary to fix ordering in relation
 547                                 to legacy SysV services, that have no
 548                                 ordering information encoded in the
 549                                 script headers. As such it should only
 550                                 be used as temporary compatibility
 551                                 option, and not be used in new unit
 552                                 files. Almost always it is a better
 553                                 choice to add explicit ordering
 554                                 directives via
 555                                 <varname>After=</varname> or
 556                                 <varname>Before=</varname>,
 557                                 instead. For more details see
 558                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 559                                 used, pass an integer value in the
 560                                 range 0-99.</para></listitem>
 561                         </varlistentry>
 562
 563                         <varlistentry>
 564                                 <term><varname>KillMode=</varname></term>
 565                                 <listitem><para>Specifies how
 566                                 processes of this service shall be
 567                                 killed. One of
 568                                 <option>control-group</option>,
 569                                 <option>process</option>,
 570                                 <option>none</option>.</para>
 571
 572                                 <para>If set to
 573                                 <option>control-group</option> all
 574                                 remaining processes in the control
 575                                 group of this service will be
 576                                 terminated on service stop, after the
 577                                 stop command (as configured with
 578                                 <varname>ExecStop=</varname>) is
 579                                 executed. If set to
 580                                 <option>process</option> only the main
 581                                 process itself is killed. If set to
 582                                 <option>none</option> no process is
 583                                 killed. In this case only the stop
 584                                 command will be executed on service
 585                                 stop, but no process be killed
 586                                 otherwise. Processes remaining alive
 587                                 after stop are left in their control
 588                                 group and the control group continues
 589                                 to exist after stop unless it is
 590                                 empty. Defaults to
 591                                 <option>control-group</option>.</para>
 592
 593                                 <para>Processes will first be
 594                                 terminated via SIGTERM (unless the
 595                                 signal to send is changed via
 596                                 <varname>KillSignal=</varname>). If
 597                                 then after a delay (configured via the
 598                                 <varname>TimeoutSec=</varname> option)
 599                                 processes still remain, the
 600                                 termination request is repeated with
 601                                 the SIGKILL signal (unless this is
 602                                 disabled via the
 603                                 <varname>SendSIGKILL=</varname>
 604                                 option). See
 605                                 <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 606                                 for more
 607                                 information.</para></listitem>
 608                         </varlistentry>
 609
 610                         <varlistentry>
 611                                 <term><varname>KillSignal=</varname></term>
 612                                 <listitem><para>Specifies which signal
 613                                 to use when killing a
 614                                 service. Defaults to SIGTERM.
 615                                 </para></listitem>
 616                         </varlistentry>
 617
 618                         <varlistentry>
 619                                 <term><varname>SendSIGKILL=</varname></term>
 620                                 <listitem><para>Specifies whether to
 621                                 send SIGKILL to remaining processes
 622                                 after a timeout, if the normal
 623                                 shutdown procedure left processes of
 624                                 the service around. Takes a boolean
 625                                 value. Defaults to "yes".
 626                                 </para></listitem>
 627                         </varlistentry>
 628
 629                         <varlistentry>
 630                                 <term><varname>NonBlocking=</varname></term>
 631                                 <listitem><para>Set O_NONBLOCK flag
 632                                 for all file descriptors passed via
 633                                 socket-based activation. If true, all
 634                                 file descriptors >= 3 (i.e. all except
 635                                 STDIN/STDOUT/STDERR) will have
 636                                 the O_NONBLOCK flag set and hence are in
 637                                 non-blocking mode. This option is only
 638                                 useful in conjunction with a socket
 639                                 unit, as described in
 640                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
 641                                 to false.</para></listitem>
 642                         </varlistentry>
 643
 644                         <varlistentry>
 645                                 <term><varname>NotifyAccess=</varname></term>
 646                                 <listitem><para>Controls access to the
 647                                 service status notification socket, as
 648                                 accessible via the
 649                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 650                                 call. Takes one of
 651                                 <option>none</option> (the default),
 652                                 <option>main</option> or
 653                                 <option>all</option>. If
 654                                 <option>none</option> no daemon status
 655                                 updates are accepted from the service
 656                                 processes, all status update messages
 657                                 are ignored. If <option>main</option>
 658                                 only service updates sent from the
 659                                 main process of the service are
 660                                 accepted. If <option>all</option> all
 661                                 services updates from all members of
 662                                 the service's control group are
 663                                 accepted. This option must be set to
 664                                 open access to the notification socket
 665                                 when using
 666                                 <varname>Type=notify</varname> (see above).</para></listitem>
 667                         </varlistentry>
 668
 669                         <varlistentry>
 670                                 <term><varname>Sockets=</varname></term>
 671                                 <listitem><para>Specifies the name of
 672                                 the socket units this service shall
 673                                 inherit the sockets from when the
 674                                 service is started. Normally it
 675                                 should not be necessary to use this
 676                                 setting as all sockets whose unit
 677                                 shares the same name as the service
 678                                 (ignoring the different suffix of course)
 679                                 are passed to the spawned
 680                                 process.</para>
 681
 682                                 <para>Note that the same socket may be
 683                                 passed to multiple processes at the
 684                                 same time. Also note that a different
 685                                 service may be activated on incoming
 686                                 traffic than inherits the sockets. Or
 687                                 in other words: The
 688                                 <varname>Service=</varname> setting of
 689                                 <filename>.socket</filename> units
 690                                 doesn't have to match the inverse of the
 691                                 <varname>Sockets=</varname> setting of
 692                                 the <filename>.service</filename> it
 693                                 refers to.</para></listitem>
 694                         </varlistentry>
 695
 696                         <varlistentry>
 697                                 <term><varname>FsckPassNo=</varname></term>
 698                                 <listitem><para>Set the fsck passno
 699                                 priority to use to order this service
 700                                 in relation to other file system
 701                                 checking services. This option is only
 702                                 necessary to fix ordering in relation
 703                                 to fsck jobs automatically created for
 704                                 all <filename>/etc/fstab</filename>
 705                                 entries with a value in the fs_passno
 706                                 column > 0. As such it should only be
 707                                 used as option for fsck
 708                                 services. Almost always it is a better
 709                                 choice to add explicit ordering
 710                                 directives via
 711                                 <varname>After=</varname> or
 712                                 <varname>Before=</varname>,
 713                                 instead. For more details see
 714                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 715                                 used, pass an integer value in the
 716                                 same range as
 717                                 <filename>/etc/fstab</filename>'s
 718                                 fs_passno column. See
 719                                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 720                                 for details.</para></listitem>
 721                         </varlistentry>
 722
 723                 </variablelist>
 724         </refsect1>
 725
 726         <refsect1>
 727                   <title>See Also</title>
 728                   <para>
 729                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 730                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 731                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 732                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 733                   </para>
 734         </refsect1>
 735
 736 </refentry>