man/systemd.service.xml

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   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
  11   systemd is free software; you can redistribute it and/or modify it
  12   under the terms of the GNU Lesser General Public License as published by
  13   the Free Software Foundation; either version 2.1 of the License, or
  14   (at your option) any later version.
  15
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  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   Lesser General Public License for more details.
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  21   You should have received a copy of the GNU Lesser General Public License
  22   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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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>Service unit configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename><replaceable>service</replaceable>.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, and in
  76                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  77                 which define the way the processes of the service are
  78                 terminated, and in
  79                 <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  80                 which configure control group settings for the
  81                 processes of the service.</para>
  82
  83                 <para>Unless <varname>DefaultDependencies=</varname>
  84                 is set to <option>false</option>, service units will
  85                 implicitly have dependencies of type
  86                 <varname>Requires=</varname> and
  87                 <varname>After=</varname> on
  88                 <filename>basic.target</filename> as well as
  89                 dependencies of type <varname>Conflicts=</varname> and
  90                 <varname>Before=</varname> on
  91                 <filename>shutdown.target</filename>. These ensure
  92                 that normal service units pull in basic system
  93                 initialization, and are terminated cleanly prior to
  94                 system shutdown. Only services involved with early
  95                 boot or late system shutdown should disable this
  96                 option.</para>
  97
  98                 <para>If a service is requested under a certain name
  99                 but no unit configuration file is found, systemd looks
 100                 for a SysV init script by the same name (with the
 101                 <filename>.service</filename> suffix removed) and
 102                 dynamically creates a service unit from that
 103                 script. This is useful for compatibility with
 104                 SysV. Note that this compatibility is quite
 105                 comprehensive but not 100%. For details about the
 106                 incompatibilities see the <ulink
 107                 url="http://www.freedesktop.org/wiki/Software/systemd/Incompatibilities">Incompatibilities
 108                 with SysV</ulink> document.
 109                 </para>
 110         </refsect1>
 111
 112         <refsect1>
 113                 <title>Options</title>
 114
 115                 <para>Service files must include a
 116                 <literal>[Service]</literal> section, which carries
 117                 information about the service and the process it
 118                 supervises. A number of options that may be used in
 119                 this section are shared with other unit types. These
 120                 options are documented in
 121                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 122                 and
 123                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
 124                 options specific to the <literal>[Service]</literal>
 125                 section of service units are the following:</para>
 126
 127                 <variablelist class='unit-directives'>
 128                         <varlistentry>
 129                                 <term><varname>Type=</varname></term>
 130
 131                                 <listitem><para>Configures the process
 132                                 start-up type for this service
 133                                 unit. One of <option>simple</option>,
 134                                 <option>forking</option>,
 135                                 <option>oneshot</option>,
 136                                 <option>dbus</option>,
 137                                 <option>notify</option> or
 138                                 <option>idle</option>.</para>
 139
 140                                 <para>If set to
 141                                 <option>simple</option> (the default
 142                                 value if <varname>BusName=</varname>
 143                                 is not specified) it is expected that
 144                                 the process configured with
 145                                 <varname>ExecStart=</varname> is the
 146                                 main process of the service. In this
 147                                 mode, if the process offers
 148                                 functionality to other processes on
 149                                 the system its communication channels
 150                                 should be installed before the daemon
 151                                 is started up (e.g. sockets set up by
 152                                 systemd, via socket activation), as
 153                                 systemd will immediately proceed
 154                                 starting follow-up units.</para>
 155
 156                                 <para>If set to
 157                                 <option>forking</option> it is
 158                                 expected that the process configured
 159                                 with <varname>ExecStart=</varname>
 160                                 will call <function>fork()</function>
 161                                 as part of its start-up. The parent process is
 162                                 expected to exit when start-up is
 163                                 complete and all communication
 164                                 channels set up. The child continues
 165                                 to run as the main daemon
 166                                 process. This is the behavior of
 167                                 traditional UNIX daemons. If this
 168                                 setting is used, it is recommended to
 169                                 also use the
 170                                 <varname>PIDFile=</varname> option, so
 171                                 that systemd can identify the main
 172                                 process of the daemon. systemd will
 173                                 proceed starting follow-up units as
 174                                 soon as the parent process
 175                                 exits.</para>
 176
 177                                 <para>Behavior of
 178                                 <option>oneshot</option> is similar
 179                                 to <option>simple</option>, however
 180                                 it is expected that the process has to
 181                                 exit before systemd starts follow-up
 182                                 units. <varname>RemainAfterExit=</varname>
 183                                 is particularly useful for this type
 184                                 of service.</para>
 185
 186                                 <para>Behavior of
 187                                 <option>dbus</option> is similar to
 188                                 <option>simple</option>, however it is
 189                                 expected that the daemon acquires a
 190                                 name on the D-Bus bus, as configured
 191                                 by
 192                                 <varname>BusName=</varname>. systemd
 193                                 will proceed starting follow-up units
 194                                 after the D-Bus bus name has been
 195                                 acquired. Service units with this
 196                                 option configured implicitly gain
 197                                 dependencies on the
 198                                 <filename>dbus.socket</filename>
 199                                 unit. This type is the default if
 200                                 <varname>BusName=</varname> is
 201                                 specified.</para>
 202
 203                                 <para>Behavior of
 204                                 <option>notify</option> is similar to
 205                                 <option>simple</option>, however it is
 206                                 expected that the daemon sends a
 207                                 notification message via
 208                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 209                                 or an equivalent call when it finished
 210                                 starting up. systemd will proceed
 211                                 starting follow-up units after this
 212                                 notification message has been sent. If
 213                                 this option is used
 214                                 <varname>NotifyAccess=</varname> (see
 215                                 below) should be set to open access to
 216                                 the notification socket provided by
 217                                 systemd. If
 218                                 <varname>NotifyAccess=</varname> is
 219                                 not set, it will be implicitly set to
 220                                 <option>main</option>.</para>
 221
 222                                 <para>Behavior of
 223                                 <option>idle</option> is very similar
 224                                 to <option>simple</option>, however
 225                                 actual execution of the service
 226                                 binary is delayed until all jobs are
 227                                 dispatched. This may be used to avoid
 228                                 interleaving of output of shell
 229                                 services with the status output on the
 230                                 console.</para>
 231                                 </listitem>
 232                         </varlistentry>
 233
 234                         <varlistentry>
 235                                 <term><varname>RemainAfterExit=</varname></term>
 236
 237                                 <listitem><para>Takes a boolean value
 238                                 that specifies whether the service
 239                                 shall be considered active even when
 240                                 all its processes exited. Defaults to
 241                                 <option>no</option>.</para>
 242                                 </listitem>
 243                         </varlistentry>
 244
 245                         <varlistentry>
 246                                 <term><varname>GuessMainPID=</varname></term>
 247
 248                                 <listitem><para>Takes a boolean value
 249                                 that specifies whether systemd should
 250                                 try to guess the main PID of a service
 251                                 if it cannot be determined
 252                                 reliably. This option is ignored
 253                                 unless <option>Type=forking</option>
 254                                 is set and <option>PIDFile=</option>
 255                                 is unset because for the other types
 256                                 or with an explicitly configured PID
 257                                 file the main PID is always known. The
 258                                 guessing algorithm might come to
 259                                 incorrect conclusions if a daemon
 260                                 consists of more than one process. If
 261                                 the main PID cannot be determined
 262                                 failure detection and automatic
 263                                 restarting of a service will not work
 264                                 reliably. Defaults to
 265                                 <option>yes</option>.</para>
 266                                 </listitem>
 267                         </varlistentry>
 268
 269                         <varlistentry>
 270                                 <term><varname>PIDFile=</varname></term>
 271
 272                                 <listitem><para>Takes an absolute file
 273                                 name pointing to the PID file of this
 274                                 daemon. Use of this option is
 275                                 recommended for services where
 276                                 <varname>Type=</varname> is set to
 277                                 <option>forking</option>. systemd will
 278                                 read the PID of the main process of
 279                                 the daemon after start-up of the
 280                                 service. systemd will not write to the
 281                                 file configured here.</para>
 282                                 </listitem>
 283                         </varlistentry>
 284
 285                         <varlistentry>
 286                                 <term><varname>BusName=</varname></term>
 287
 288                                 <listitem><para>Takes a D-Bus bus
 289                                 name, that this service is reachable
 290                                 as. This option is mandatory for
 291                                 services where
 292                                 <varname>Type=</varname> is set to
 293                                 <option>dbus</option>, but its use
 294                                 is otherwise recommended as well if
 295                                 the process takes a name on the D-Bus
 296                                 bus.</para>
 297                                 </listitem>
 298                         </varlistentry>
 299
 300                         <varlistentry>
 301                                 <term><varname>ExecStart=</varname></term>
 302                                 <listitem><para>Commands with their
 303                                 arguments that are executed when this
 304                                 service is started. The first
 305                                 argument must be an absolute path
 306                                 name.</para>
 307
 308                                 <para>When <varname>Type</varname> is
 309                                 not <option>oneshot</option>, only one
 310                                 command may be given. When
 311                                 <varname>Type=oneshot</varname> is
 312                                 used, more than one command may be
 313                                 specified. Multiple command lines may
 314                                 be concatenated in a single directive,
 315                                 by separating them with semicolons
 316                                 (these semicolons must be passed as
 317                                 separate words). Alternatively, this
 318                                 directive may be specified more than
 319                                 once with the same effect. However,
 320                                 the latter syntax is not recommended
 321                                 for compatibility with parsers
 322                                 suitable for XDG
 323                                 <filename>.desktop</filename> files.
 324                                 Lone semicolons may be escaped as
 325                                 <literal>\;</literal>. If the empty
 326                                 string is assigned to this option the
 327                                 list of commands to start is reset,
 328                                 prior assignments of this option will
 329                                 have no effect.</para>
 330
 331                                 <para>If more than one command is
 332                                 specified, the commands are invoked
 333                                 one by one sequentially in the order
 334                                 they appear in the unit file. If one
 335                                 of the commands fails (and is not
 336                                 prefixed with <literal>-</literal>),
 337                                 other lines are not executed and the
 338                                 unit is considered failed.</para>
 339
 340                                 <para>Unless
 341                                 <varname>Type=forking</varname> is
 342                                 set, the process started via this
 343                                 command line will be considered the
 344                                 main process of the daemon.</para>
 345
 346                                 <para>The command line accepts
 347                                 <literal>%</literal> specifiers as
 348                                 described in
 349                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note
 350                                 that the first argument of the command
 351                                 line (i.e. the program to execute) may
 352                                 not include specifiers.</para>
 353
 354                                 <para>Basic environment variable
 355                                 substitution is supported. Use
 356                                 <literal>${FOO}</literal> as part of a
 357                                 word, or as a word of its own on the
 358                                 command line, in which case it will be
 359                                 replaced by the value of the
 360                                 environment variable including all
 361                                 whitespace it contains, resulting in a
 362                                 single argument.  Use
 363                                 <literal>$FOO</literal> as a separate
 364                                 word on the command line, in which
 365                                 case it will be replaced by the value
 366                                 of the environment variable split up
 367                                 at whitespace, resulting in zero or
 368                                 more arguments. Note that the first
 369                                 argument (i.e. the program to execute)
 370                                 may not be a variable, since it must
 371                                 be a literal and absolute path
 372                                 name.</para>
 373
 374                                 <para>Optionally, if the absolute file
 375                                 name is prefixed with
 376                                 <literal>@</literal>, the second token
 377                                 will be passed as
 378                                 <literal>argv[0]</literal> to the
 379                                 executed process, followed by the
 380                                 further arguments specified. If the
 381                                 absolute filename is prefixed with
 382                                 <literal>-</literal> an exit code of
 383                                 the command normally considered a
 384                                 failure (i.e. non-zero exit status or
 385                                 abnormal exit due to signal) is ignored
 386                                 and considered success. If both
 387                                 <literal>-</literal> and
 388                                 <literal>@</literal> are used they
 389                                 can appear in either order.</para>
 390
 391                                 <para>Note that this setting does not
 392                                 directly support shell command
 393                                 lines. If shell command lines are to
 394                                 be used they need to be passed
 395                                 explicitly to a shell implementation
 396                                 of some kind. Example:</para>
 397                                 <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'
 398                                 </programlisting>
 399
 400                                 <para>For services run by a user
 401                                 instance of systemd the special
 402                                 environment variable
 403                                 <varname>$MANAGERPID</varname> is set
 404                                 to the PID of the systemd
 405                                 instance.</para>
 406                                 </listitem>
 407                         </varlistentry>
 408
 409                         <varlistentry>
 410                                 <term><varname>ExecStartPre=</varname></term>
 411                                 <term><varname>ExecStartPost=</varname></term>
 412                                 <listitem><para>Additional commands
 413                                 that are executed before or after
 414                                 the command in
 415                                 <varname>ExecStart=</varname>, respectively.
 416                                 Syntax is the same as for
 417                                 <varname>ExecStart=</varname>, except
 418                                 that multiple command lines are allowed
 419                                 and the commands are executed one
 420                                 after the other, serially.</para>
 421
 422                                 <para>If any of those commands (not
 423                                 prefixed with <literal>-</literal>)
 424                                 fail, the rest are not executed and
 425                                 the unit is considered failed.</para>
 426                                 </listitem>
 427                         </varlistentry>
 428
 429                         <varlistentry>
 430                                 <term><varname>ExecReload=</varname></term>
 431                                 <listitem><para>Commands to execute to
 432                                 trigger a configuration reload in the
 433                                 service. This argument takes multiple
 434                                 command lines, following the same
 435                                 scheme as described for
 436                                 <varname>ExecStart=</varname>
 437                                 above. Use of this setting is
 438                                 optional. Specifier and environment
 439                                 variable substitution is supported
 440                                 here following the same scheme as for
 441                                 <varname>ExecStart=</varname>.</para>
 442
 443                                 <para>One additional special
 444                                 environment variables is set: if known
 445                                 <varname>$MAINPID</varname> is set to
 446                                 the main process of the daemon, and
 447                                 may be used for command lines like the
 448                                 following:</para>
 449
 450                                 <programlisting>/bin/kill -HUP $MAINPID</programlisting>
 451                                 </listitem>
 452                         </varlistentry>
 453
 454                         <varlistentry>
 455                                 <term><varname>ExecStop=</varname></term>
 456                                 <listitem><para>Commands to execute to
 457                                 stop the service started via
 458                                 <varname>ExecStart=</varname>. This
 459                                 argument takes multiple command lines,
 460                                 following the same scheme as described
 461                                 for <varname>ExecStart=</varname>
 462                                 above. Use of this setting is
 463                                 optional. All processes remaining for
 464                                 a service after the commands
 465                                 configured in this option are run are
 466                                 terminated according to the
 467                                 <varname>KillMode=</varname> setting
 468                                 (see
 469                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
 470                                 this option is not specified the
 471                                 process is terminated right-away when
 472                                 service stop is requested. Specifier
 473                                 and environment variable substitution
 474                                 is supported (including
 475                                 <varname>$MAINPID</varname>, see
 476                                 above).</para></listitem>
 477                         </varlistentry>
 478
 479                         <varlistentry>
 480                                 <term><varname>ExecStopPost=</varname></term>
 481                                 <listitem><para>Additional commands
 482                                 that are executed after the service
 483                                 was stopped. This includes cases where
 484                                 the commands configured in
 485                                 <varname>ExecStop=</varname> were used,
 486                                 where the service doesn't have any
 487                                 <varname>ExecStop=</varname> defined, or
 488                                 where the service exited unexpectedly. This
 489                                 argument takes multiple command lines,
 490                                 following the same scheme as described
 491                                 for <varname>ExecStart</varname>. Use
 492                                 of these settings is
 493                                 optional. Specifier and environment
 494                                 variable substitution is
 495                                 supported.</para></listitem>
 496                         </varlistentry>
 497
 498                         <varlistentry>
 499                                 <term><varname>RestartSec=</varname></term>
 500                                 <listitem><para>Configures the time to
 501                                 sleep before restarting a service (as
 502                                 configured with
 503                                 <varname>Restart=</varname>). Takes a
 504                                 unit-less value in seconds, or a time
 505                                 span value such as "5min
 506                                 20s". Defaults to
 507                                 100ms.</para></listitem>
 508                         </varlistentry>
 509
 510                         <varlistentry>
 511                                 <term><varname>TimeoutStartSec=</varname></term>
 512                                 <listitem><para>Configures the time to
 513                                 wait for start-up. If a
 514                                 daemon service does not signal
 515                                 start-up completion within the
 516                                 configured time, the service will be
 517                                 considered failed and be shut down
 518                                 again.
 519                                 Takes a unit-less value in seconds, or a
 520                                 time span value such as "5min
 521                                 20s". Pass 0 to disable the timeout
 522                                 logic. Defaults to 90s, except when
 523                                 <varname>Type=oneshot</varname> is
 524                                 used in which case the timeout
 525                                 is disabled by default.
 526                                 </para></listitem>
 527                         </varlistentry>
 528
 529                         <varlistentry>
 530                                 <term><varname>TimeoutStopSec=</varname></term>
 531                                 <listitem><para>Configures the time to
 532                                 wait for stop. If a service is asked
 533                                 to stop but does not terminate in the
 534                                 specified time, it will be terminated
 535                                 forcibly via <constant>SIGTERM</constant>, and after
 536                                 another delay of this time with
 537                                 <constant>SIGKILL</constant> (See
 538                                 <varname>KillMode=</varname>
 539                                 in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 540                                 Takes a unit-less value in seconds, or a
 541                                 time span value such as "5min
 542                                 20s". Pass 0 to disable the timeout
 543                                 logic. Defaults to 90s.
 544                                 </para></listitem>
 545                         </varlistentry>
 546
 547                         <varlistentry>
 548                                 <term><varname>TimeoutSec=</varname></term>
 549                                 <listitem><para>A shorthand for configuring
 550                                 both <varname>TimeoutStartSec=</varname>
 551                                 and <varname>TimeoutStopSec=</varname>
 552                                 to the specified value.
 553                                 </para></listitem>
 554                         </varlistentry>
 555
 556                         <varlistentry>
 557                                 <term><varname>WatchdogSec=</varname></term>
 558                                 <listitem><para>Configures the
 559                                 watchdog timeout for a service. The
 560                                 watchdog is activated when the start-up is
 561                                 completed. The service must call
 562                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 563                                 regularly with "WATCHDOG=1" (i.e. the
 564                                 "keep-alive ping"). If the time
 565                                 between two such calls is larger than
 566                                 the configured time then the service
 567                                 is placed in a failure state. By
 568                                 setting <varname>Restart=</varname> to
 569                                 <option>on-failure</option> or
 570                                 <option>always</option> the service
 571                                 will be automatically restarted. The
 572                                 time configured here will be passed to
 573                                 the executed service process in the
 574                                 <varname>WATCHDOG_USEC=</varname>
 575                                 environment variable. This allows
 576                                 daemons to automatically enable the
 577                                 keep-alive pinging logic if watchdog
 578                                 support is enabled for the service. If
 579                                 this option is used
 580                                 <varname>NotifyAccess=</varname> (see
 581                                 below) should be set to open access to
 582                                 the notification socket provided by
 583                                 systemd. If
 584                                 <varname>NotifyAccess=</varname> is
 585                                 not set, it will be implicitly set to
 586                                 <option>main</option>. Defaults to 0,
 587                                 which disables this
 588                                 feature.</para></listitem>
 589                         </varlistentry>
 590
 591                         <varlistentry>
 592                                 <term><varname>Restart=</varname></term>
 593                                 <listitem><para>Configures whether the
 594                                 service shall be restarted when the
 595                                 service process exits, is killed,
 596                                 or a timeout is reached. The service
 597                                 process may be the main service
 598                                 process, but also one of the processes
 599                                 specified with
 600                                 <varname>ExecStartPre=</varname>,
 601                                 <varname>ExecStartPost=</varname>,
 602                                 <varname>ExecStopPre=</varname>,
 603                                 <varname>ExecStopPost=</varname>, or
 604                                 <varname>ExecReload=</varname>.
 605                                 When the death of the process is a
 606                                 result of systemd operation (e.g. service
 607                                 stop or restart), the service will not be
 608                                 restarted. Timeouts include missing
 609                                 the watchdog "keep-alive ping"
 610                                 deadline and a service start, reload,
 611                                 and stop operation timeouts.</para>
 612
 613                                 <para>Takes one of
 614                                 <option>no</option>,
 615                                 <option>on-success</option>,
 616                                 <option>on-failure</option>,
 617                                 <option>on-abort</option>, or
 618                                 <option>always</option>. If set to
 619                                 <option>no</option> (the default) the
 620                                 service will not be restarted. If set to
 621                                 <option>on-success</option> it will be
 622                                 restarted only when the service process
 623                                 exits cleanly.
 624                                 In this context, a clean exit means
 625                                 an exit code of 0, or one of the signals
 626                                 <constant>SIGHUP</constant>, <constant>SIGINT</constant>, <constant>SIGTERM</constant>, or <constant>SIGPIPE</constant>, and
 627                                 additionally, exit statuses and signals
 628                                 specified in <varname>SuccessExitStatus=</varname>.
 629                                 If set to <option>on-failure</option>
 630                                 the service will be restarted when the
 631                                 process exits with an nonzero exit code,
 632                                 is terminated by a signal (including on
 633                                 core dump), when an operation (such as
 634                                 service reload) times out, and when the
 635                                 configured watchdog timeout is triggered.
 636                                 If set to
 637                                 <option>on-abort</option> the service
 638                                 will be restarted only if the service
 639                                 process exits due to an uncaught
 640                                 signal not specified as a clean exit
 641                                 status.
 642                                 If set to
 643                                 <option>always</option> the service
 644                                 will be restarted regardless whether
 645                                 it exited cleanly or not, got
 646                                 terminated abnormally by a signal or
 647                                 hit a timeout.</para>
 648
 649                                 <para>In addition to the above settings,
 650                                 the service will not be restarted if the
 651                                 exit code or signal is specified in
 652                                 <varname>RestartPreventExitStatus=</varname>
 653                                 (see below).</para></listitem>
 654                         </varlistentry>
 655
 656                         <varlistentry>
 657                                 <term><varname>SuccessExitStatus=</varname></term>
 658                                 <listitem><para>Takes a list of exit
 659                                 status definitions that when returned
 660                                 by the main service process will be
 661                                 considered successful termination, in
 662                                 addition to the normal successful exit
 663                                 code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
 664                                 <constant>SIGTERM</constant> and <constant>SIGPIPE</constant>. Exit status
 665                                 definitions can either be numeric exit
 666                                 codes or termination signal names,
 667                                 separated by spaces. Example:
 668                                 <literal>SuccessExitStatus=1 2 8
 669                                 <constant>SIGKILL</constant></literal>, ensures that exit
 670                                 codes 1, 2, 8 and the termination
 671                                 signal <constant>SIGKILL</constant> are considered clean
 672                                 service terminations. This option may
 673                                 appear more than once in which case
 674                                 the list of successful exit statuses
 675                                 is merged. If the empty string is
 676                                 assigned to this option the list is
 677                                 reset, all prior assignments of this
 678                                 option will have no
 679                                 effect.</para></listitem>
 680                         </varlistentry>
 681
 682                         <varlistentry>
 683                                 <term><varname>RestartPreventExitStatus=</varname></term>
 684                                 <listitem><para>Takes a list of exit
 685                                 status definitions that when returned
 686                                 by the main service process will
 687                                 prevent automatic service restarts
 688                                 regardless of the restart setting
 689                                 configured with
 690                                 <varname>Restart=</varname>. Exit
 691                                 status definitions can either be
 692                                 numeric exit codes or termination
 693                                 signal names, and are separated by
 694                                 spaces. Defaults to the empty list, so
 695                                 that by default no exit status is
 696                                 excluded from the configured restart
 697                                 logic. Example:
 698                                 <literal>RestartPreventExitStatus=1 6
 699                                 SIGABRT</literal>, ensures that exit
 700                                 codes 1 and 6 and the termination
 701                                 signal SIGABRT will not result in
 702                                 automatic service restarting. This
 703                                 option may appear more than once in
 704                                 which case the list of restart preventing
 705                                 statuses is merged. If the empty
 706                                 string is assigned to this option the
 707                                 list is reset, all prior assignments
 708                                 of this option will have no
 709                                 effect.</para></listitem>
 710                         </varlistentry>
 711
 712                         <varlistentry>
 713                                 <term><varname>PermissionsStartOnly=</varname></term>
 714                                 <listitem><para>Takes a boolean
 715                                 argument. If true, the permission
 716                                 related execution options as
 717                                 configured with
 718                                 <varname>User=</varname> and similar
 719                                 options (see
 720                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 721                                 for more information) are only applied
 722                                 to the process started with
 723                                 <varname>ExecStart=</varname>, and not
 724                                 to the various other
 725                                 <varname>ExecStartPre=</varname>,
 726                                 <varname>ExecStartPost=</varname>,
 727                                 <varname>ExecReload=</varname>,
 728                                 <varname>ExecStop=</varname>,
 729                                 <varname>ExecStopPost=</varname>
 730                                 commands. If false, the setting is
 731                                 applied to all configured commands the
 732                                 same way. Defaults to
 733                                 false.</para></listitem>
 734                         </varlistentry>
 735
 736                         <varlistentry>
 737                                 <term><varname>RootDirectoryStartOnly=</varname></term>
 738                                 <listitem><para>Takes a boolean
 739                                 argument. If true, the root directory
 740                                 as configured with the
 741                                 <varname>RootDirectory=</varname>
 742                                 option (see
 743                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 744                                 for more information) is only applied
 745                                 to the process started with
 746                                 <varname>ExecStart=</varname>, and not
 747                                 to the various other
 748                                 <varname>ExecStartPre=</varname>,
 749                                 <varname>ExecStartPost=</varname>,
 750                                 <varname>ExecReload=</varname>,
 751                                 <varname>ExecStop=</varname>,
 752                                 <varname>ExecStopPost=</varname>
 753                                 commands. If false, the setting is
 754                                 applied to all configured commands the
 755                                 same way. Defaults to
 756                                 false.</para></listitem>
 757                         </varlistentry>
 758
 759                         <varlistentry>
 760                                 <term><varname>NonBlocking=</varname></term>
 761                                 <listitem><para>Set O_NONBLOCK flag
 762                                 for all file descriptors passed via
 763                                 socket-based activation. If true, all
 764                                 file descriptors >= 3 (i.e. all except
 765                                 STDIN/STDOUT/STDERR) will have
 766                                 the O_NONBLOCK flag set and hence are in
 767                                 non-blocking mode. This option is only
 768                                 useful in conjunction with a socket
 769                                 unit, as described in
 770                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
 771                                 to false.</para></listitem>
 772                         </varlistentry>
 773
 774                         <varlistentry>
 775                                 <term><varname>NotifyAccess=</varname></term>
 776                                 <listitem><para>Controls access to the
 777                                 service status notification socket, as
 778                                 accessible via the
 779                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 780                                 call. Takes one of
 781                                 <option>none</option> (the default),
 782                                 <option>main</option> or
 783                                 <option>all</option>. If
 784                                 <option>none</option> no daemon status
 785                                 updates are accepted from the service
 786                                 processes, all status update messages
 787                                 are ignored. If <option>main</option>
 788                                 only service updates sent from the
 789                                 main process of the service are
 790                                 accepted. If <option>all</option> all
 791                                 services updates from all members of
 792                                 the service's control group are
 793                                 accepted. This option should be set to
 794                                 open access to the notification socket
 795                                 when using
 796                                 <varname>Type=notify</varname> or
 797                                 <varname>WatchdogSec=</varname> (see
 798                                 above). If those options are used but
 799                                 <varname>NotifyAccess=</varname> not
 800                                 configured it will be implicitly set
 801                                 to
 802                                 <option>main</option>.</para></listitem>
 803                         </varlistentry>
 804
 805                         <varlistentry>
 806                                 <term><varname>Sockets=</varname></term>
 807                                 <listitem><para>Specifies the name of
 808                                 the socket units this service shall
 809                                 inherit the sockets from when the
 810                                 service is started. Normally it
 811                                 should not be necessary to use this
 812                                 setting as all sockets whose unit
 813                                 shares the same name as the service
 814                                 (ignoring the different suffix of course)
 815                                 are passed to the spawned
 816                                 process.</para>
 817
 818                                 <para>Note that the same socket may be
 819                                 passed to multiple processes at the
 820                                 same time. Also note that a different
 821                                 service may be activated on incoming
 822                                 traffic than inherits the sockets. Or
 823                                 in other words: the
 824                                 <varname>Service=</varname> setting of
 825                                 <filename>.socket</filename> units
 826                                 doesn't have to match the inverse of
 827                                 the <varname>Sockets=</varname>
 828                                 setting of the
 829                                 <filename>.service</filename> it
 830                                 refers to.</para>
 831
 832                                 <para>This option may appear more than
 833                                 once, in which case the list of socket
 834                                 units is merged. If the empty string
 835                                 is assigned to this option the list of
 836                                 sockets is reset, all prior uses of
 837                                 this setting will have no
 838                                 effect.</para></listitem>
 839                         </varlistentry>
 840
 841                         <varlistentry>
 842                                 <term><varname>StartLimitInterval=</varname></term>
 843                                 <term><varname>StartLimitBurst=</varname></term>
 844
 845                                 <listitem><para>Configure service
 846                                 start rate limiting. By default
 847                                 services which are started more often
 848                                 than 5 times within 10s are not
 849                                 permitted to start any more times
 850                                 until the 10s interval ends. With
 851                                 these two options this rate limiting
 852                                 may be modified. Use
 853                                 <varname>StartLimitInterval=</varname>
 854                                 to configure the checking interval
 855                                 (defaults to 10s, set to 0 to disable
 856                                 any kind of rate limiting). Use
 857                                 <varname>StartLimitBurst=</varname> to
 858                                 configure how many starts per interval
 859                                 are allowed (defaults to 5). These
 860                                 configuration options are particularly
 861                                 useful in conjunction with
 862                                 <varname>Restart=</varname>, however
 863                                 apply to all kinds of starts
 864                                 (including manual), not just those
 865                                 triggered by the
 866                                 <varname>Restart=</varname> logic.
 867                                 Note that units which are configured
 868                                 for <varname>Restart=</varname> and
 869                                 which reach the start limit are not
 870                                 attempted to be restarted anymore,
 871                                 however they may still be restarted
 872                                 manually at a later point from which
 873                                 point on the restart logic is again
 874                                 activated. Note that
 875                                 <command>systemctl
 876                                 reset-failed</command> will cause the
 877                                 restart rate counter for a service to
 878                                 be flushed, which is useful if the
 879                                 administrator wants to manually start
 880                                 a service and the start limit
 881                                 interferes with
 882                                 that.</para></listitem>
 883                         </varlistentry>
 884
 885                         <varlistentry>
 886                                 <term><varname>StartLimitAction=</varname></term>
 887
 888                                 <listitem><para>Configure the action
 889                                 to take if the rate limit configured
 890                                 with
 891                                 <varname>StartLimitInterval=</varname>
 892                                 and
 893                                 <varname>StartLimitBurst=</varname> is
 894                                 hit. Takes one of
 895                                 <option>none</option>,
 896                                 <option>reboot</option>,
 897                                 <option>reboot-force</option> or
 898                                 <option>reboot-immediate</option>. If
 899                                 <option>none</option> is set,
 900                                 hitting the rate limit will trigger no
 901                                 action besides that the start will not
 902                                 be
 903                                 permitted. <option>reboot</option>
 904                                 causes a reboot following the normal
 905                                 shutdown procedure (i.e. equivalent to
 906                                 <command>systemctl reboot</command>),
 907                                 <option>reboot-force</option> causes
 908                                 an forced reboot which will terminate
 909                                 all processes forcibly but should
 910                                 cause no dirty file systems on reboot
 911                                 (i.e. equivalent to <command>systemctl
 912                                 reboot -f</command>) and
 913                                 <option>reboot-immediate</option>
 914                                 causes immediate execution of the
 915                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 916                                 system call, which might result in
 917                                 data loss.  Defaults to
 918                                 <option>none</option>.</para></listitem>
 919                         </varlistentry>
 920
 921                 </variablelist>
 922
 923                 <para>Check
 924                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 925                 and
 926                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 927                 for more settings.</para>
 928
 929         </refsect1>
 930
 931         <refsect1>
 932                 <title>Compatibility Options</title>
 933
 934                 <para>The following options are also available in the
 935                 <literal>[Service]</literal> section, but exist purely
 936                 for compatibility reasons and should not be used in
 937                 newly written service files.</para>
 938
 939                 <variablelist class='unit-directives'>
 940                         <varlistentry>
 941                                 <term><varname>SysVStartPriority=</varname></term>
 942                                 <listitem><para>Set the SysV start
 943                                 priority to use to order this service
 944                                 in relation to SysV services lacking
 945                                 LSB headers. This option is only
 946                                 necessary to fix ordering in relation
 947                                 to legacy SysV services, that have no
 948                                 ordering information encoded in the
 949                                 script headers. As such it should only
 950                                 be used as temporary compatibility
 951                                 option, and not be used in new unit
 952                                 files. Almost always it is a better
 953                                 choice to add explicit ordering
 954                                 directives via
 955                                 <varname>After=</varname> or
 956                                 <varname>Before=</varname>,
 957                                 instead. For more details see
 958                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 959                                 used, pass an integer value in the
 960                                 range 0-99.</para></listitem>
 961                         </varlistentry>
 962
 963                         <varlistentry>
 964                                 <term><varname>FsckPassNo=</varname></term>
 965                                 <listitem><para>Set the fsck passno
 966                                 priority to use to order this service
 967                                 in relation to other file system
 968                                 checking services. This option is only
 969                                 necessary to fix ordering in relation
 970                                 to fsck jobs automatically created for
 971                                 all <filename>/etc/fstab</filename>
 972                                 entries with a value in the fs_passno
 973                                 column > 0. As such it should only be
 974                                 used as option for fsck
 975                                 services. Almost always it is a better
 976                                 choice to add explicit ordering
 977                                 directives via
 978                                 <varname>After=</varname> or
 979                                 <varname>Before=</varname>,
 980                                 instead. For more details see
 981                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 982                                 used, pass an integer value in the
 983                                 same range as
 984                                 <filename>/etc/fstab</filename>'s
 985                                 fs_passno column. See
 986                                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 987                                 for details.</para></listitem>
 988                         </varlistentry>
 989
 990                 </variablelist>
 991         </refsect1>
 992
 993         <refsect1>
 994                   <title>See Also</title>
 995                   <para>
 996                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 997                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 998                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 999                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1000                           <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1001                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1002                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1003                   </para>
1004         </refsect1>
1005
1006 </refentry>