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. This includes cases where
 468                                 the commands configured in
 469                                 <varname>ExecStop=</varname> were used,
 470                                 where the service doesn't have any
 471                                 <varname>ExecStop=</varname> defined, or
 472                                 where the service exited unexpectedly. This
 473                                 argument takes multiple command lines,
 474                                 following the same scheme as described
 475                                 for <varname>ExecStart</varname>. Use
 476                                 of these settings is
 477                                 optional. Specifier and environment
 478                                 variable substitution is
 479                                 supported.</para></listitem>
 480                         </varlistentry>
 481
 482                         <varlistentry>
 483                                 <term><varname>RestartSec=</varname></term>
 484                                 <listitem><para>Configures the time to
 485                                 sleep before restarting a service (as
 486                                 configured with
 487                                 <varname>Restart=</varname>). Takes a
 488                                 unit-less value in seconds, or a time
 489                                 span value such as "5min
 490                                 20s". Defaults to
 491                                 100ms.</para></listitem>
 492                         </varlistentry>
 493
 494                         <varlistentry>
 495                                 <term><varname>TimeoutStartSec=</varname></term>
 496                                 <listitem><para>Configures the time to
 497                                 wait for start-up. If a
 498                                 daemon service does not signal
 499                                 start-up completion within the
 500                                 configured time, the service will be
 501                                 considered failed and be shut down
 502                                 again.
 503                                 Takes a unit-less value in seconds, or a
 504                                 time span value such as "5min
 505                                 20s". Pass 0 to disable the timeout
 506                                 logic. Defaults to 90s, except when
 507                                 <varname>Type=oneshot</varname> is
 508                                 used in which case the timeout
 509                                 is disabled by default.
 510                                 </para></listitem>
 511                         </varlistentry>
 512
 513                         <varlistentry>
 514                                 <term><varname>TimeoutStopSec=</varname></term>
 515                                 <listitem><para>Configures the time to
 516                                 wait for stop. If a service is asked
 517                                 to stop but does not terminate in the
 518                                 specified time, it will be terminated
 519                                 forcibly via SIGTERM, and after
 520                                 another delay of this time with
 521                                 SIGKILL (See
 522                                 <varname>KillMode=</varname>
 523                                 in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 524                                 Takes a unit-less value in seconds, or a
 525                                 time span value such as "5min
 526                                 20s". Pass 0 to disable the timeout
 527                                 logic. Defaults to 90s.
 528                                 </para></listitem>
 529                         </varlistentry>
 530
 531                         <varlistentry>
 532                                 <term><varname>TimeoutSec=</varname></term>
 533                                 <listitem><para>A shorthand for configuring
 534                                 both <varname>TimeoutStartSec=</varname>
 535                                 and <varname>TimeoutStopSec=</varname>
 536                                 to the specified value.
 537                                 </para></listitem>
 538                         </varlistentry>
 539
 540                         <varlistentry>
 541                                 <term><varname>WatchdogSec=</varname></term>
 542                                 <listitem><para>Configures the
 543                                 watchdog timeout for a service. This
 544                                 is activated when the start-up is
 545                                 completed. The service must call
 546                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 547                                 regularly with "WATCHDOG=1" (i.e. the
 548                                 "keep-alive ping"). If the time
 549                                 between two such calls is larger than
 550                                 the configured time then the service
 551                                 is placed in a failure state. By
 552                                 setting <varname>Restart=</varname> to
 553                                 <option>on-failure</option> or
 554                                 <option>always</option> the service
 555                                 will be automatically restarted. The
 556                                 time configured here will be passed to
 557                                 the executed service process in the
 558                                 <varname>WATCHDOG_USEC=</varname>
 559                                 environment variable. This allows
 560                                 daemons to automatically enable the
 561                                 keep-alive pinging logic if watchdog
 562                                 support is enabled for the service. If
 563                                 this option is used
 564                                 <varname>NotifyAccess=</varname> (see
 565                                 below) should be set to open access to
 566                                 the notification socket provided by
 567                                 systemd. If
 568                                 <varname>NotifyAccess=</varname> is
 569                                 not set, it will be implicitly set to
 570                                 <option>main</option>. Defaults to 0,
 571                                 which disables this
 572                                 feature.</para></listitem>
 573                         </varlistentry>
 574
 575                         <varlistentry>
 576                                 <term><varname>Restart=</varname></term>
 577                                 <listitem><para>Configures whether the
 578                                 main service process shall be
 579                                 restarted when it exits. Takes one of
 580                                 <option>no</option>,
 581                                 <option>on-success</option>,
 582                                 <option>on-failure</option>,
 583                                 <option>on-abort</option> or
 584                                 <option>always</option>. If set to
 585                                 <option>no</option> (the default) the
 586                                 service will not be restarted when it
 587                                 exits. If set to
 588                                 <option>on-success</option> it will be
 589                                 restarted only when it exited cleanly,
 590                                 i.e. terminated with an exit code of
 591                                 0. If set to
 592                                 <option>on-failure</option> it will be
 593                                 restarted only when it exited with an
 594                                 exit code not equaling 0, when
 595                                 terminated by a signal (including on
 596                                 core dump), when an operation (such as
 597                                 service reload) times out or when the
 598                                 configured watchdog timeout is
 599                                 triggered. If set to
 600                                 <option>on-abort</option> it will be
 601                                 restarted only if it exits due to
 602                                 reception of an uncaught signal
 603                                 (including on core dump). If set to
 604                                 <option>always</option> the service
 605                                 will be restarted regardless whether
 606                                 it exited cleanly or not, got
 607                                 terminated abnormally by a signal or
 608                                 hit a timeout.</para></listitem>
 609                         </varlistentry>
 610
 611                         <varlistentry>
 612                                 <term><varname>SuccessExitStatus=</varname></term>
 613                                 <listitem><para>Takes a list of exit
 614                                 status definitions that when returned
 615                                 by the main service process will be
 616                                 considered successful termination, in
 617                                 addition to the normal successful exit
 618                                 code 0 and the signals SIGHUP, SIGINT,
 619                                 SIGTERM and SIGPIPE. Exit status
 620                                 definitions can either be numeric exit
 621                                 codes or termination signal names, and
 622                                 are separated by spaces. Example:
 623                                 "<literal>SuccessExitStatus=1 2 8
 624                                 SIGKILL</literal>", ensures that exit
 625                                 codes 1, 2, 8 and the termination
 626                                 signal SIGKILL are considered clean
 627                                 service terminations. This option may
 628                                 appear more than once in which case
 629                                 the list of successful exit statuses
 630                                 is merged. If the empty string is
 631                                 assigned to this option the list is
 632                                 reset, all prior assignments of this
 633                                 option will have no
 634                                 effect.</para></listitem>
 635                         </varlistentry>
 636
 637                         <varlistentry>
 638                                 <term><varname>RestartPreventExitStatus=</varname></term>
 639                                 <listitem><para>Takes a list of exit
 640                                 status definitions that when returned
 641                                 by the main service process will
 642                                 prevent automatic service restarts
 643                                 regardless of the restart setting
 644                                 configured with
 645                                 <varname>Restart=</varname>. Exit
 646                                 status definitions can either be
 647                                 numeric exit codes or termination
 648                                 signal names, and are separated by
 649                                 spaces. Defaults to the empty list, so
 650                                 that by default no exit status is
 651                                 excluded from the configured restart
 652                                 logic. Example:
 653                                 "<literal>RestartPreventExitStatus=1 6
 654                                 SIGABRT</literal>", ensures that exit
 655                                 codes 1 and 6 and the termination
 656                                 signal SIGABRT will not result in
 657                                 automatic service restarting. This
 658                                 option may appear more than once in
 659                                 which case the list of restart preventing
 660                                 statuses is merged. If the empty
 661                                 string is assigned to this option the
 662                                 list is reset, all prior assignments
 663                                 of this option will have no
 664                                 effect.</para></listitem>
 665                         </varlistentry>
 666
 667                         <varlistentry>
 668                                 <term><varname>PermissionsStartOnly=</varname></term>
 669                                 <listitem><para>Takes a boolean
 670                                 argument. If true, the permission
 671                                 related execution options as
 672                                 configured with
 673                                 <varname>User=</varname> and similar
 674                                 options (see
 675                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 676                                 for more information) are only applied
 677                                 to the process started with
 678                                 <varname>ExecStart=</varname>, and not
 679                                 to the various other
 680                                 <varname>ExecStartPre=</varname>,
 681                                 <varname>ExecStartPost=</varname>,
 682                                 <varname>ExecReload=</varname>,
 683                                 <varname>ExecStop=</varname>,
 684                                 <varname>ExecStopPost=</varname>
 685                                 commands. If false, the setting is
 686                                 applied to all configured commands the
 687                                 same way. Defaults to
 688                                 false.</para></listitem>
 689                         </varlistentry>
 690
 691                         <varlistentry>
 692                                 <term><varname>RootDirectoryStartOnly=</varname></term>
 693                                 <listitem><para>Takes a boolean
 694                                 argument. If true, the root directory
 695                                 as configured with the
 696                                 <varname>RootDirectory=</varname>
 697                                 option (see
 698                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 699                                 for more information) is only applied
 700                                 to the process started with
 701                                 <varname>ExecStart=</varname>, and not
 702                                 to the various other
 703                                 <varname>ExecStartPre=</varname>,
 704                                 <varname>ExecStartPost=</varname>,
 705                                 <varname>ExecReload=</varname>,
 706                                 <varname>ExecStop=</varname>,
 707                                 <varname>ExecStopPost=</varname>
 708                                 commands. If false, the setting is
 709                                 applied to all configured commands the
 710                                 same way. Defaults to
 711                                 false.</para></listitem>
 712                         </varlistentry>
 713
 714                         <varlistentry>
 715                                 <term><varname>NonBlocking=</varname></term>
 716                                 <listitem><para>Set O_NONBLOCK flag
 717                                 for all file descriptors passed via
 718                                 socket-based activation. If true, all
 719                                 file descriptors >= 3 (i.e. all except
 720                                 STDIN/STDOUT/STDERR) will have
 721                                 the O_NONBLOCK flag set and hence are in
 722                                 non-blocking mode. This option is only
 723                                 useful in conjunction with a socket
 724                                 unit, as described in
 725                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
 726                                 to false.</para></listitem>
 727                         </varlistentry>
 728
 729                         <varlistentry>
 730                                 <term><varname>NotifyAccess=</varname></term>
 731                                 <listitem><para>Controls access to the
 732                                 service status notification socket, as
 733                                 accessible via the
 734                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 735                                 call. Takes one of
 736                                 <option>none</option> (the default),
 737                                 <option>main</option> or
 738                                 <option>all</option>. If
 739                                 <option>none</option> no daemon status
 740                                 updates are accepted from the service
 741                                 processes, all status update messages
 742                                 are ignored. If <option>main</option>
 743                                 only service updates sent from the
 744                                 main process of the service are
 745                                 accepted. If <option>all</option> all
 746                                 services updates from all members of
 747                                 the service's control group are
 748                                 accepted. This option should be set to
 749                                 open access to the notification socket
 750                                 when using
 751                                 <varname>Type=notify</varname> or
 752                                 <varname>WatchdogSec=</varname> (see
 753                                 above). If those options are used but
 754                                 <varname>NotifyAccess=</varname> not
 755                                 configured it will be implicitly set
 756                                 to
 757                                 <option>main</option>.</para></listitem>
 758                         </varlistentry>
 759
 760                         <varlistentry>
 761                                 <term><varname>Sockets=</varname></term>
 762                                 <listitem><para>Specifies the name of
 763                                 the socket units this service shall
 764                                 inherit the sockets from when the
 765                                 service is started. Normally it
 766                                 should not be necessary to use this
 767                                 setting as all sockets whose unit
 768                                 shares the same name as the service
 769                                 (ignoring the different suffix of course)
 770                                 are passed to the spawned
 771                                 process.</para>
 772
 773                                 <para>Note that the same socket may be
 774                                 passed to multiple processes at the
 775                                 same time. Also note that a different
 776                                 service may be activated on incoming
 777                                 traffic than inherits the sockets. Or
 778                                 in other words: the
 779                                 <varname>Service=</varname> setting of
 780                                 <filename>.socket</filename> units
 781                                 doesn't have to match the inverse of
 782                                 the <varname>Sockets=</varname>
 783                                 setting of the
 784                                 <filename>.service</filename> it
 785                                 refers to.</para>
 786
 787                                 <para>This option may appear more than
 788                                 once, in which case the list of socket
 789                                 units is merged. If the empty string
 790                                 is assigned to this option the list of
 791                                 sockets is reset, all prior uses of
 792                                 this setting will have no
 793                                 effect.</para></listitem>
 794                         </varlistentry>
 795
 796                         <varlistentry>
 797                                 <term><varname>StartLimitInterval=</varname></term>
 798                                 <term><varname>StartLimitBurst=</varname></term>
 799
 800                                 <listitem><para>Configure service
 801                                 start rate limiting. By default
 802                                 services which are started more often
 803                                 than 5 times within 10s are not
 804                                 permitted to start any more times
 805                                 until the 10s interval ends. With
 806                                 these two options this rate limiting
 807                                 may be modified. Use
 808                                 <varname>StartLimitInterval=</varname>
 809                                 to configure the checking interval
 810                                 (defaults to 10s, set to 0 to disable
 811                                 any kind of rate limiting). Use
 812                                 <varname>StartLimitBurst=</varname> to
 813                                 configure how many starts per interval
 814                                 are allowed (defaults to 5). These
 815                                 configuration options are particularly
 816                                 useful in conjunction with
 817                                 <varname>Restart=</varname>, however
 818                                 apply to all kinds of starts
 819                                 (including manual), not just those
 820                                 triggered by the
 821                                 <varname>Restart=</varname> logic.
 822                                 Note that units which are configured
 823                                 for <varname>Restart=</varname> and
 824                                 which reach the start limit are not
 825                                 attempted to be restarted anymore,
 826                                 however they may still be restarted
 827                                 manually at a later point from which
 828                                 point on the restart logic is again
 829                                 activated. Note that
 830                                 <command>systemctl
 831                                 reset-failed</command> will cause the
 832                                 restart rate counter for a service to
 833                                 be flushed, which is useful if the
 834                                 administrator wants to manually start
 835                                 a service and the start limit
 836                                 interferes with
 837                                 that.</para></listitem>
 838                         </varlistentry>
 839
 840                         <varlistentry>
 841                                 <term><varname>StartLimitAction=</varname></term>
 842
 843                                 <listitem><para>Configure the action
 844                                 to take if the rate limit configured
 845                                 with
 846                                 <varname>StartLimitInterval=</varname>
 847                                 and
 848                                 <varname>StartLimitBurst=</varname> is
 849                                 hit. Takes one of
 850                                 <option>none</option>,
 851                                 <option>reboot</option>,
 852                                 <option>reboot-force</option> or
 853                                 <option>reboot-immediate</option>. If
 854                                 <option>none</option> is set,
 855                                 hitting the rate limit will trigger no
 856                                 action besides that the start will not
 857                                 be
 858                                 permitted. <option>reboot</option>
 859                                 causes a reboot following the normal
 860                                 shutdown procedure (i.e. equivalent to
 861                                 <command>systemctl reboot</command>),
 862                                 <option>reboot-force</option> causes
 863                                 an forced reboot which will terminate
 864                                 all processes forcibly but should
 865                                 cause no dirty file systems on reboot
 866                                 (i.e. equivalent to <command>systemctl
 867                                 reboot -f</command>) and
 868                                 <option>reboot-immediate</option>
 869                                 causes immediate execution of the
 870                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 871                                 system call, which might result in
 872                                 data loss.  Defaults to
 873                                 <option>none</option>.</para></listitem>
 874                         </varlistentry>
 875
 876                 </variablelist>
 877
 878                 <para>Check
 879                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 880                 and
 881                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 882                 for more settings.</para>
 883
 884         </refsect1>
 885
 886         <refsect1>
 887                 <title>Compatibility Options</title>
 888
 889                 <para>The following options are also available in the
 890                 <literal>[Service]</literal> section, but exist purely
 891                 for compatibility reasons and should not be used in
 892                 newly written service files.</para>
 893
 894                 <variablelist class='unit-directives'>
 895                         <varlistentry>
 896                                 <term><varname>SysVStartPriority=</varname></term>
 897                                 <listitem><para>Set the SysV start
 898                                 priority to use to order this service
 899                                 in relation to SysV services lacking
 900                                 LSB headers. This option is only
 901                                 necessary to fix ordering in relation
 902                                 to legacy SysV services, that have no
 903                                 ordering information encoded in the
 904                                 script headers. As such it should only
 905                                 be used as temporary compatibility
 906                                 option, and not be used in new unit
 907                                 files. Almost always it is a better
 908                                 choice to add explicit ordering
 909                                 directives via
 910                                 <varname>After=</varname> or
 911                                 <varname>Before=</varname>,
 912                                 instead. For more details see
 913                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 914                                 used, pass an integer value in the
 915                                 range 0-99.</para></listitem>
 916                         </varlistentry>
 917
 918                         <varlistentry>
 919                                 <term><varname>FsckPassNo=</varname></term>
 920                                 <listitem><para>Set the fsck passno
 921                                 priority to use to order this service
 922                                 in relation to other file system
 923                                 checking services. This option is only
 924                                 necessary to fix ordering in relation
 925                                 to fsck jobs automatically created for
 926                                 all <filename>/etc/fstab</filename>
 927                                 entries with a value in the fs_passno
 928                                 column > 0. As such it should only be
 929                                 used as option for fsck
 930                                 services. Almost always it is a better
 931                                 choice to add explicit ordering
 932                                 directives via
 933                                 <varname>After=</varname> or
 934                                 <varname>Before=</varname>,
 935                                 instead. For more details see
 936                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 937                                 used, pass an integer value in the
 938                                 same range as
 939                                 <filename>/etc/fstab</filename>'s
 940                                 fs_passno column. See
 941                                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 942                                 for details.</para></listitem>
 943                         </varlistentry>
 944
 945                 </variablelist>
 946         </refsect1>
 947
 948         <refsect1>
 949                   <title>See Also</title>
 950                   <para>
 951                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 952                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 953                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 954                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 955                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 956                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 957                   </para>
 958         </refsect1>
 959
 960 </refentry>