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