man/systemd.service.xml

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   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
  11   systemd is free software; you can redistribute it and/or modify it
  12   under the terms of the GNU Lesser General Public License as published by
  13   the Free Software Foundation; either version 2.1 of the License, or
  14   (at your option) any later version.
  15
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  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   Lesser General Public License for more details.
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  21   You should have received a copy of the GNU Lesser General Public License
  22   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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  24
  25 <refentry id="systemd.service">
  26         <refentryinfo>
  27                 <title>systemd.service</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd.service</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.service</refname>
  47                 <refpurpose>Service unit configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename></para>
  52         </refsynopsisdiv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  57                 <para>A unit configuration file whose name ends in
  58                 <filename>.service</filename> encodes information
  59                 about a process controlled and supervised by
  60                 systemd.</para>
  61
  62                 <para>This man page lists the configuration options
  63                 specific to this unit type. See
  64                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  65                 for the common options of all unit configuration
  66                 files. The common configuration items are configured
  67                 in the generic <literal>[Unit]</literal> and
  68                 <literal>[Install]</literal> sections. The service
  69                 specific configuration options are configured in the
  70                 <literal>[Service]</literal> section.</para>
  71
  72                 <para>Additional options are listed in
  73                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  74                 which define the execution environment the commands
  75                 are executed in, 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>
 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.
 302                                 </para>
 303
 304                                 <para>When
 305                                 <varname>Type=oneshot</varname> is
 306                                 used, more than one command may be
 307                                 specified. Multiple command lines may
 308                                 be concatenated in a single directive,
 309                                 by separating them with semicolons
 310                                 (these semicolons must be passed as
 311                                 separate words). Alternatively, this
 312                                 directive may be specified more than
 313                                 once with the same effect. However,
 314                                 the latter syntax is not recommended
 315                                 for compatibility with parsers
 316                                 suitable for XDG
 317                                 <filename>.desktop</filename> files.
 318                                 The commands are invoked one by one
 319                                 sequentially in the order they appear
 320                                 in the unit file.  When
 321                                 <varname>Type</varname> is not
 322                                 <option>oneshot</option>, only one
 323                                 command may be given. Lone semicolons
 324                                 may be escaped as
 325                                 '<literal>\;</literal>'. If the empty
 326                                 string is assigned to this option the
 327                                 list of commands to start is reset,
 328                                 prior assignments of this option will
 329                                 have no effect.</para>
 330
 331                                 <para>Unless
 332                                 <varname>Type=forking</varname> is
 333                                 set, the process started via this
 334                                 command line will be considered the
 335                                 main process of the daemon.</para>
 336
 337                                 <para>The command line accepts
 338                                 '<literal>%</literal>' specifiers as
 339                                 described in
 340                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note
 341                                 that the first argument of the command
 342                                 line (i.e. the program to execute) may
 343                                 not include specifiers.</para>
 344
 345                                 <para>On top of that basic environment
 346                                 variable substitution is
 347                                 supported. Use
 348                                 <literal>${FOO}</literal> as part of a
 349                                 word, or as a word of its own on the
 350                                 command line, in which case it will be
 351                                 replaced by the value of the
 352                                 environment variable including all
 353                                 whitespace it contains, resulting in a
 354                                 single argument.  Use
 355                                 <literal>$FOO</literal> as a separate
 356                                 word on the command line, in which
 357                                 case it will be replaced by the value
 358                                 of the environment variable split up
 359                                 at whitespace, resulting in no or more
 360                                 arguments. Note that the first
 361                                 argument (i.e. the program to execute)
 362                                 may not be a variable, and must be a
 363                                 literal and absolute path
 364                                 name.</para>
 365
 366                                 <para>Optionally, if the absolute file
 367                                 name is prefixed with
 368                                 '<literal>@</literal>', the second token
 369                                 will be passed as
 370                                 <literal>argv[0]</literal> to the
 371                                 executed process, followed by the
 372                                 further arguments specified. If the
 373                                 absolute file name is prefixed with
 374                                 '<literal>-</literal>' an exit code of
 375                                 the command normally considered a
 376                                 failure (i.e. non-zero exit status or
 377                                 abnormal exit due to signal) is ignored
 378                                 and considered success. If both
 379                                 '<literal>-</literal>' and
 380                                 '<literal>@</literal>' are used they
 381                                 can appear in either order.</para>
 382
 383                                 <para>Note that this setting does not
 384                                 directly support shell command
 385                                 lines. If shell command lines are to
 386                                 be used they need to be passed
 387                                 explicitly to a shell implementation
 388                                 of some kind. Example:
 389                                 <literal>ExecStart=/bin/sh -c 'dmesg | tac'</literal></para>
 390
 391                                 <para>For services run by a user
 392                                 instance of systemd the special
 393                                 environment variable
 394                                 <literal>MANAGERPID</literal> is set
 395                                 to the PID of the systemd
 396                                 instance.</para>
 397                                 </listitem>
 398                         </varlistentry>
 399
 400                         <varlistentry>
 401                                 <term><varname>ExecStartPre=</varname></term>
 402                                 <term><varname>ExecStartPost=</varname></term>
 403                                 <listitem><para>Additional commands
 404                                 that are executed before or after
 405                                 the command in
 406                                 <varname>ExecStart=</varname>, respectively.
 407                                 Syntax is the same as for
 408                                 <varname>ExecStart=</varname>, except
 409                                 that multiple command lines are allowed
 410                                 and the commands are executed one
 411                                 after the other, serially.</para>
 412                                 </listitem>
 413                         </varlistentry>
 414
 415                         <varlistentry>
 416                                 <term><varname>ExecReload=</varname></term>
 417                                 <listitem><para>Commands to execute to
 418                                 trigger a configuration reload in the
 419                                 service. This argument takes multiple
 420                                 command lines, following the same
 421                                 scheme as described for
 422                                 <varname>ExecStart=</varname>
 423                                 above. Use of this setting is
 424                                 optional. Specifier and environment
 425                                 variable substitution is supported
 426                                 here following the same scheme as for
 427                                 <varname>ExecStart=</varname>. One
 428                                 additional special environment
 429                                 variables is set: if known
 430                                 <literal>$MAINPID</literal> is set to
 431                                 the main process of the daemon, and
 432                                 may be used for command lines like the
 433                                 following: <command>/bin/kill -HUP
 434                                 $MAINPID</command>.</para></listitem>
 435                         </varlistentry>
 436
 437                         <varlistentry>
 438                                 <term><varname>ExecStop=</varname></term>
 439                                 <listitem><para>Commands to execute to
 440                                 stop the service started via
 441                                 <varname>ExecStart=</varname>. This
 442                                 argument takes multiple command lines,
 443                                 following the same scheme as described
 444                                 for <varname>ExecStart=</varname>
 445                                 above. Use of this setting is
 446                                 optional. All processes remaining for
 447                                 a service after the commands
 448                                 configured in this option are run are
 449                                 terminated according to the
 450                                 <varname>KillMode=</varname> setting
 451                                 (see
 452                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
 453                                 this option is not specified the
 454                                 process is terminated right-away when
 455                                 service stop is requested. Specifier
 456                                 and environment variable substitution
 457                                 is supported (including
 458                                 <literal>$MAINPID</literal>, see
 459                                 above).</para></listitem>
 460                         </varlistentry>
 461
 462                         <varlistentry>
 463                                 <term><varname>ExecStopPost=</varname></term>
 464                                 <listitem><para>Additional commands
 465                                 that are executed after the service
 466                                 was stopped using the commands
 467                                 configured in
 468                                 <varname>ExecStop=</varname>. This
 469                                 argument takes multiple command lines,
 470                                 following the same scheme as described
 471                                 for <varname>ExecStart</varname>. Use
 472                                 of these settings is
 473                                 optional. Specifier and environment
 474                                 variable substitution is
 475                                 supported.</para></listitem>
 476                         </varlistentry>
 477
 478                         <varlistentry>
 479                                 <term><varname>RestartSec=</varname></term>
 480                                 <listitem><para>Configures the time to
 481                                 sleep before restarting a service (as
 482                                 configured with
 483                                 <varname>Restart=</varname>). Takes a
 484                                 unit-less value in seconds, or a time
 485                                 span value such as "5min
 486                                 20s". Defaults to
 487                                 100ms.</para></listitem>
 488                         </varlistentry>
 489
 490                         <varlistentry>
 491                                 <term><varname>TimeoutStartSec=</varname></term>
 492                                 <listitem><para>Configures the time to
 493                                 wait for start-up. If a
 494                                 daemon service does not signal
 495                                 start-up completion within the
 496                                 configured time, the service will be
 497                                 considered failed and be shut down
 498                                 again.
 499                                 Takes a unit-less value in seconds, or a
 500                                 time span value such as "5min
 501                                 20s". Pass 0 to disable the timeout
 502                                 logic. Defaults to 90s, except when
 503                                 <varname>Type=oneshot</varname> is
 504                                 used in which case the timeout
 505                                 is disabled by default.
 506                                 </para></listitem>
 507                         </varlistentry>
 508
 509                         <varlistentry>
 510                                 <term><varname>TimeoutStopSec=</varname></term>
 511                                 <listitem><para>Configures the time to
 512                                 wait for stop. If a service is asked
 513                                 to stop but does not terminate in the
 514                                 specified time, it will be terminated
 515                                 forcibly via SIGTERM, and after
 516                                 another delay of this time with
 517                                 SIGKILL (See
 518                                 <varname>KillMode=</varname>
 519                                 in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 520                                 Takes a unit-less value in seconds, or a
 521                                 time span value such as "5min
 522                                 20s". Pass 0 to disable the timeout
 523                                 logic. Defaults to 90s.
 524                                 </para></listitem>
 525                         </varlistentry>
 526
 527                         <varlistentry>
 528                                 <term><varname>TimeoutSec=</varname></term>
 529                                 <listitem><para>A shorthand for configuring
 530                                 both <varname>TimeoutStartSec=</varname>
 531                                 and <varname>TimeoutStopSec=</varname>
 532                                 to the specified value.
 533                                 </para></listitem>
 534                         </varlistentry>
 535
 536                         <varlistentry>
 537                                 <term><varname>WatchdogSec=</varname></term>
 538                                 <listitem><para>Configures the
 539                                 watchdog timeout for a service. This
 540                                 is activated when the start-up is
 541                                 completed. The service must call
 542                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 543                                 regularly with "WATCHDOG=1" (i.e. the
 544                                 "keep-alive ping"). If the time
 545                                 between two such calls is larger than
 546                                 the configured time then the service
 547                                 is placed in a failure state. By
 548                                 setting <varname>Restart=</varname> to
 549                                 <option>on-failure</option> or
 550                                 <option>always</option> the service
 551                                 will be automatically restarted. The
 552                                 time configured here will be passed to
 553                                 the executed service process in the
 554                                 <varname>WATCHDOG_USEC=</varname>
 555                                 environment variable. This allows
 556                                 daemons to automatically enable the
 557                                 keep-alive pinging logic if watchdog
 558                                 support is enabled for the service. If
 559                                 this option is used
 560                                 <varname>NotifyAccess=</varname> (see
 561                                 below) should be set to open access to
 562                                 the notification socket provided by
 563                                 systemd. If
 564                                 <varname>NotifyAccess=</varname> is
 565                                 not set, it will be implicitly set to
 566                                 <option>main</option>. Defaults to 0,
 567                                 which disables this
 568                                 feature.</para></listitem>
 569                         </varlistentry>
 570
 571                         <varlistentry>
 572                                 <term><varname>Restart=</varname></term>
 573                                 <listitem><para>Configures whether the
 574                                 main service process shall be
 575                                 restarted when it exits. Takes one of
 576                                 <option>no</option>,
 577                                 <option>on-success</option>,
 578                                 <option>on-failure</option>,
 579                                 <option>on-abort</option> or
 580                                 <option>always</option>. If set to
 581                                 <option>no</option> (the default) the
 582                                 service will not be restarted when it
 583                                 exits. If set to
 584                                 <option>on-success</option> it will be
 585                                 restarted only when it exited cleanly,
 586                                 i.e. terminated with an exit code of
 587                                 0. If set to
 588                                 <option>on-failure</option> it will be
 589                                 restarted only when it exited with an
 590                                 exit code not equaling 0, when
 591                                 terminated by a signal (including on
 592                                 core dump), when an operation (such as
 593                                 service reload) times out or when the
 594                                 configured watchdog timeout is
 595                                 triggered. If set to
 596                                 <option>on-abort</option> it will be
 597                                 restarted only if it exits due to
 598                                 reception of an uncaught signal
 599                                 (including on core dump). If set to
 600                                 <option>always</option> the service
 601                                 will be restarted regardless whether
 602                                 it exited cleanly or not, got
 603                                 terminated abnormally by a signal or
 604                                 hit a timeout.</para></listitem>
 605                         </varlistentry>
 606
 607                         <varlistentry>
 608                                 <term><varname>SuccessExitStatus=</varname></term>
 609                                 <listitem><para>Takes a list of exit
 610                                 status definitions that when returned
 611                                 by the main service process will be
 612                                 considered successful termination, in
 613                                 addition to the normal successful exit
 614                                 code 0 and the signals SIGHUP, SIGINT,
 615                                 SIGTERM and SIGPIPE. Exit status
 616                                 definitions can either be numeric exit
 617                                 codes or termination signal names, and
 618                                 are separated by spaces. Example:
 619                                 "<literal>SuccessExitStatus=1 2 8
 620                                 SIGKILL</literal>", ensures that exit
 621                                 codes 1, 2, 8 and the termination
 622                                 signal SIGKILL are considered clean
 623                                 service terminations. This option may
 624                                 appear more than once in which case
 625                                 the list of successful exit statuses
 626                                 is merged. If the empty string is
 627                                 assigned to this option the list is
 628                                 reset, all prior assignments of this
 629                                 option will have no
 630                                 effect.</para></listitem>
 631                         </varlistentry>
 632
 633                         <varlistentry>
 634                                 <term><varname>RestartPreventExitStatus=</varname></term>
 635                                 <listitem><para>Takes a list of exit
 636                                 status definitions that when returned
 637                                 by the main service process will
 638                                 prevent automatic service restarts
 639                                 regardless of the restart setting
 640                                 configured with
 641                                 <varname>Restart=</varname>. Exit
 642                                 status definitions can either be
 643                                 numeric exit codes or termination
 644                                 signal names, and are separated by
 645                                 spaces. Defaults to the empty list, so
 646                                 that by default no exit status is
 647                                 excluded from the configured restart
 648                                 logic. Example:
 649                                 "<literal>RestartPreventExitStatus=1 6
 650                                 SIGABRT</literal>", ensures that exit
 651                                 codes 1 and 6 and the termination
 652                                 signal SIGABRT will not result in
 653                                 automatic service restarting. This
 654                                 option may appear more than once in
 655                                 which case the list of restart preventing
 656                                 statuses is merged. If the empty
 657                                 string is assigned to this option the
 658                                 list is reset, all prior assignments
 659                                 of this option will have no
 660                                 effect.</para></listitem>
 661                         </varlistentry>
 662
 663                         <varlistentry>
 664                                 <term><varname>PermissionsStartOnly=</varname></term>
 665                                 <listitem><para>Takes a boolean
 666                                 argument. If true, the permission
 667                                 related execution options as
 668                                 configured with
 669                                 <varname>User=</varname> and similar
 670                                 options (see
 671                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 672                                 for more information) are only applied
 673                                 to the process started with
 674                                 <varname>ExecStart=</varname>, and not
 675                                 to the various other
 676                                 <varname>ExecStartPre=</varname>,
 677                                 <varname>ExecStartPost=</varname>,
 678                                 <varname>ExecReload=</varname>,
 679                                 <varname>ExecStop=</varname>,
 680                                 <varname>ExecStopPost=</varname>
 681                                 commands. If false, the setting is
 682                                 applied to all configured commands the
 683                                 same way. Defaults to
 684                                 false.</para></listitem>
 685                         </varlistentry>
 686
 687                         <varlistentry>
 688                                 <term><varname>RootDirectoryStartOnly=</varname></term>
 689                                 <listitem><para>Takes a boolean
 690                                 argument. If true, the root directory
 691                                 as configured with the
 692                                 <varname>RootDirectory=</varname>
 693                                 option (see
 694                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 695                                 for more information) is only applied
 696                                 to the process started with
 697                                 <varname>ExecStart=</varname>, and not
 698                                 to the various other
 699                                 <varname>ExecStartPre=</varname>,
 700                                 <varname>ExecStartPost=</varname>,
 701                                 <varname>ExecReload=</varname>,
 702                                 <varname>ExecStop=</varname>,
 703                                 <varname>ExecStopPost=</varname>
 704                                 commands. If false, the setting is
 705                                 applied to all configured commands the
 706                                 same way. Defaults to
 707                                 false.</para></listitem>
 708                         </varlistentry>
 709
 710                         <varlistentry>
 711                                 <term><varname>NonBlocking=</varname></term>
 712                                 <listitem><para>Set O_NONBLOCK flag
 713                                 for all file descriptors passed via
 714                                 socket-based activation. If true, all
 715                                 file descriptors >= 3 (i.e. all except
 716                                 STDIN/STDOUT/STDERR) will have
 717                                 the O_NONBLOCK flag set and hence are in
 718                                 non-blocking mode. This option is only
 719                                 useful in conjunction with a socket
 720                                 unit, as described in
 721                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
 722                                 to false.</para></listitem>
 723                         </varlistentry>
 724
 725                         <varlistentry>
 726                                 <term><varname>NotifyAccess=</varname></term>
 727                                 <listitem><para>Controls access to the
 728                                 service status notification socket, as
 729                                 accessible via the
 730                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 731                                 call. Takes one of
 732                                 <option>none</option> (the default),
 733                                 <option>main</option> or
 734                                 <option>all</option>. If
 735                                 <option>none</option> no daemon status
 736                                 updates are accepted from the service
 737                                 processes, all status update messages
 738                                 are ignored. If <option>main</option>
 739                                 only service updates sent from the
 740                                 main process of the service are
 741                                 accepted. If <option>all</option> all
 742                                 services updates from all members of
 743                                 the service's control group are
 744                                 accepted. This option should be set to
 745                                 open access to the notification socket
 746                                 when using
 747                                 <varname>Type=notify</varname> or
 748                                 <varname>WatchdogSec=</varname> (see
 749                                 above). If those options are used but
 750                                 <varname>NotifyAccess=</varname> not
 751                                 configured it will be implicitly set
 752                                 to
 753                                 <option>main</option>.</para></listitem>
 754                         </varlistentry>
 755
 756                         <varlistentry>
 757                                 <term><varname>Sockets=</varname></term>
 758                                 <listitem><para>Specifies the name of
 759                                 the socket units this service shall
 760                                 inherit the sockets from when the
 761                                 service is started. Normally it
 762                                 should not be necessary to use this
 763                                 setting as all sockets whose unit
 764                                 shares the same name as the service
 765                                 (ignoring the different suffix of course)
 766                                 are passed to the spawned
 767                                 process.</para>
 768
 769                                 <para>Note that the same socket may be
 770                                 passed to multiple processes at the
 771                                 same time. Also note that a different
 772                                 service may be activated on incoming
 773                                 traffic than inherits the sockets. Or
 774                                 in other words: the
 775                                 <varname>Service=</varname> setting of
 776                                 <filename>.socket</filename> units
 777                                 doesn't have to match the inverse of
 778                                 the <varname>Sockets=</varname>
 779                                 setting of the
 780                                 <filename>.service</filename> it
 781                                 refers to.</para>
 782
 783                                 <para>This option may appear more than
 784                                 once, in which case the list of socket
 785                                 units is merged. If the empty string
 786                                 is assigned to this option the list of
 787                                 sockets is reset, all prior uses of
 788                                 this setting will have no
 789                                 effect.</para></listitem>
 790                         </varlistentry>
 791
 792                         <varlistentry>
 793                                 <term><varname>StartLimitInterval=</varname></term>
 794                                 <term><varname>StartLimitBurst=</varname></term>
 795
 796                                 <listitem><para>Configure service
 797                                 start rate limiting. By default
 798                                 services which are started more often
 799                                 than 5 times within 10s are not
 800                                 permitted to start any more times
 801                                 until the 10s interval ends. With
 802                                 these two options this rate limiting
 803                                 may be modified. Use
 804                                 <varname>StartLimitInterval=</varname>
 805                                 to configure the checking interval
 806                                 (defaults to 10s, set to 0 to disable
 807                                 any kind of rate limiting). Use
 808                                 <varname>StartLimitBurst=</varname> to
 809                                 configure how many starts per interval
 810                                 are allowed (defaults to 5). These
 811                                 configuration options are particularly
 812                                 useful in conjunction with
 813                                 <varname>Restart=</varname>, however
 814                                 apply to all kinds of starts
 815                                 (including manual), not just those
 816                                 triggered by the
 817                                 <varname>Restart=</varname> logic.
 818                                 Note that units which are configured
 819                                 for <varname>Restart=</varname> and
 820                                 which reach the start limit are not
 821                                 attempted to be restarted anymore,
 822                                 however they may still be restarted
 823                                 manually at a later point from which
 824                                 point on the restart logic is again
 825                                 activated. Note that
 826                                 <command>systemctl
 827                                 reset-failed</command> will cause the
 828                                 restart rate counter for a service to
 829                                 be flushed, which is useful if the
 830                                 administrator wants to manually start
 831                                 a service and the start limit
 832                                 interferes with
 833                                 that.</para></listitem>
 834                         </varlistentry>
 835
 836                         <varlistentry>
 837                                 <term><varname>StartLimitAction=</varname></term>
 838
 839                                 <listitem><para>Configure the action
 840                                 to take if the rate limit configured
 841                                 with
 842                                 <varname>StartLimitInterval=</varname>
 843                                 and
 844                                 <varname>StartLimitBurst=</varname> is
 845                                 hit. Takes one of
 846                                 <option>none</option>,
 847                                 <option>reboot</option>,
 848                                 <option>reboot-force</option> or
 849                                 <option>reboot-immediate</option>. If
 850                                 <option>none</option> is set,
 851                                 hitting the rate limit will trigger no
 852                                 action besides that the start will not
 853                                 be
 854                                 permitted. <option>reboot</option>
 855                                 causes a reboot following the normal
 856                                 shutdown procedure (i.e. equivalent to
 857                                 <command>systemctl reboot</command>),
 858                                 <option>reboot-force</option> causes
 859                                 an forced reboot which will terminate
 860                                 all processes forcibly but should
 861                                 cause no dirty file systems on reboot
 862                                 (i.e. equivalent to <command>systemctl
 863                                 reboot -f</command>) and
 864                                 <option>reboot-immediate</option>
 865                                 causes immediate execution of the
 866                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 867                                 system call, which might result in
 868                                 data loss.  Defaults to
 869                                 <option>none</option>.</para></listitem>
 870                         </varlistentry>
 871
 872                 </variablelist>
 873
 874                 <para>Check
 875                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 876                 and
 877                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 878                 for more settings.</para>
 879
 880         </refsect1>
 881
 882         <refsect1>
 883                 <title>Compatibility Options</title>
 884
 885                 <para>The following options are also available in the
 886                 <literal>[Service]</literal> section, but exist purely
 887                 for compatibility reasons and should not be used in
 888                 newly written service files.</para>
 889
 890                 <variablelist>
 891                         <varlistentry>
 892                                 <term><varname>SysVStartPriority=</varname></term>
 893                                 <listitem><para>Set the SysV start
 894                                 priority to use to order this service
 895                                 in relation to SysV services lacking
 896                                 LSB headers. This option is only
 897                                 necessary to fix ordering in relation
 898                                 to legacy SysV services, that have no
 899                                 ordering information encoded in the
 900                                 script headers. As such it should only
 901                                 be used as temporary compatibility
 902                                 option, and not be used in new unit
 903                                 files. Almost always it is a better
 904                                 choice to add explicit ordering
 905                                 directives via
 906                                 <varname>After=</varname> or
 907                                 <varname>Before=</varname>,
 908                                 instead. For more details see
 909                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 910                                 used, pass an integer value in the
 911                                 range 0-99.</para></listitem>
 912                         </varlistentry>
 913
 914                         <varlistentry>
 915                                 <term><varname>FsckPassNo=</varname></term>
 916                                 <listitem><para>Set the fsck passno
 917                                 priority to use to order this service
 918                                 in relation to other file system
 919                                 checking services. This option is only
 920                                 necessary to fix ordering in relation
 921                                 to fsck jobs automatically created for
 922                                 all <filename>/etc/fstab</filename>
 923                                 entries with a value in the fs_passno
 924                                 column > 0. As such it should only be
 925                                 used as option for fsck
 926                                 services. Almost always it is a better
 927                                 choice to add explicit ordering
 928                                 directives via
 929                                 <varname>After=</varname> or
 930                                 <varname>Before=</varname>,
 931                                 instead. For more details see
 932                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
 933                                 used, pass an integer value in the
 934                                 same range as
 935                                 <filename>/etc/fstab</filename>'s
 936                                 fs_passno column. See
 937                                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 938                                 for details.</para></listitem>
 939                         </varlistentry>
 940
 941                 </variablelist>
 942         </refsect1>
 943
 944         <refsect1>
 945                   <title>See Also</title>
 946                   <para>
 947                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 948                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 949                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 950                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 951                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 952                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 953                   </para>
 954         </refsect1>
 955
 956 </refentry>