summaryrefslogtreecommitdiff
path: root/man/systemd.service.xml
blob: be9bdcaf99689d5e03d34ac3090f6ce0fdcebfca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
<?xml version='1.0'?> <!--*-nxml-*-->
<?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!--
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->

<refentry id="systemd.service">
        <refentryinfo>
                <title>systemd.service</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </refentryinfo>

        <refmeta>
                <refentrytitle>systemd.service</refentrytitle>
                <manvolnum>5</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>systemd.service</refname>
                <refpurpose>Service unit configuration</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <para><filename><replaceable>service</replaceable>.service</filename></para>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para>A unit configuration file whose name ends in
                <filename>.service</filename> encodes information
                about a process controlled and supervised by
                systemd.</para>

                <para>This man page lists the configuration options
                specific to this unit type. See
                <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                for the common options of all unit configuration
                files. The common configuration items are configured
                in the generic <literal>[Unit]</literal> and
                <literal>[Install]</literal> sections. The service
                specific configuration options are configured in the
                <literal>[Service]</literal> section.</para>

                <para>Additional options are listed in
                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                which define the execution environment the commands
                are executed in, and in
                <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                which define the way the processes of the service are
                terminated, and in
                <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                which configure resource control settings for the
                processes of the service.</para>

                <para>Unless <varname>DefaultDependencies=</varname>
                is set to <option>false</option>, service units will
                implicitly have dependencies of type
                <varname>Requires=</varname> and
                <varname>After=</varname> on
                <filename>basic.target</filename> as well as
                dependencies of type <varname>Conflicts=</varname> and
                <varname>Before=</varname> on
                <filename>shutdown.target</filename>. These ensure
                that normal service units pull in basic system
                initialization, and are terminated cleanly prior to
                system shutdown. Only services involved with early
                boot or late system shutdown should disable this
                option.</para>

                <para>If a service is requested under a certain name
                but no unit configuration file is found, systemd looks
                for a SysV init script by the same name (with the
                <filename>.service</filename> suffix removed) and
                dynamically creates a service unit from that
                script. This is useful for compatibility with
                SysV. Note that this compatibility is quite
                comprehensive but not 100%. For details about the
                incompatibilities, see the <ulink
                url="http://www.freedesktop.org/wiki/Software/systemd/Incompatibilities">Incompatibilities
                with SysV</ulink> document.
                </para>
        </refsect1>

        <refsect1>
                <title>Options</title>

                <para>Service files must include a
                <literal>[Service]</literal> section, which carries
                information about the service and the process it
                supervises. A number of options that may be used in
                this section are shared with other unit types. These
                options are documented in
                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                and
                <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
                options specific to the <literal>[Service]</literal>
                section of service units are the following:</para>

                <variablelist class='unit-directives'>
                        <varlistentry>
                                <term><varname>Type=</varname></term>

                                <listitem><para>Configures the process
                                start-up type for this service
                                unit. One of <option>simple</option>,
                                <option>forking</option>,
                                <option>oneshot</option>,
                                <option>dbus</option>,
                                <option>notify</option> or
                                <option>idle</option>.</para>

                                <para>If set to
                                <option>simple</option> (the default
                                value if neither
                                <varname>Type=</varname> nor
                                <varname>BusName=</varname> are
                                specified), it is expected that the
                                process configured with
                                <varname>ExecStart=</varname> is the
                                main process of the service. In this
                                mode, if the process offers
                                functionality to other processes on
                                the system, its communication channels
                                should be installed before the daemon
                                is started up (e.g. sockets set up by
                                systemd, via socket activation), as
                                systemd will immediately proceed
                                starting follow-up units.</para>

                                <para>If set to
                                <option>forking</option>, it is
                                expected that the process configured
                                with <varname>ExecStart=</varname>
                                will call <function>fork()</function>
                                as part of its start-up. The parent process is
                                expected to exit when start-up is
                                complete and all communication
                                channels are set up. The child continues
                                to run as the main daemon
                                process. This is the behavior of
                                traditional UNIX daemons. If this
                                setting is used, it is recommended to
                                also use the
                                <varname>PIDFile=</varname> option, so
                                that systemd can identify the main
                                process of the daemon. systemd will
                                proceed with starting follow-up units
                                as soon as the parent process
                                exits.</para>

                                <para>Behavior of
                                <option>oneshot</option> is similar
                                to <option>simple</option>; however,
                                it is expected that the process has to
                                exit before systemd starts follow-up
                                units. <varname>RemainAfterExit=</varname>
                                is particularly useful for this type
                                of service.</para>

                                <para>Behavior of
                                <option>dbus</option> is similar to
                                <option>simple</option>; however, it is
                                expected that the daemon acquires a
                                name on the D-Bus bus, as configured
                                by
                                <varname>BusName=</varname>. systemd
                                will proceed with starting follow-up
                                units after the D-Bus bus name has been
                                acquired. Service units with this
                                option configured implicitly gain
                                dependencies on the
                                <filename>dbus.socket</filename>
                                unit. This type is the default if
                                <varname>BusName=</varname> is
                                specified.</para>

                                <para>Behavior of
                                <option>notify</option> is similar to
                                <option>simple</option>; however, it is
                                expected that the daemon sends a
                                notification message via
                                <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                or an equivalent call when it has finished
                                starting up. systemd will proceed with
                                starting follow-up units after this
                                notification message has been sent. If
                                this option is used,
                                <varname>NotifyAccess=</varname> (see
                                below) should be set to open access to
                                the notification socket provided by
                                systemd. If
                                <varname>NotifyAccess=</varname> is
                                not set, it will be implicitly set to
                                <option>main</option>. Note that
                                currently
                                <varname>Type=</varname><option>notify</option>
                                will not work if used in combination with
                                <varname>PrivateNetwork=</varname><option>yes</option>.</para>

                                <para>Behavior of
                                <option>idle</option> is very similar
                                to <option>simple</option>; however,
                                actual execution of the service
                                binary is delayed until all jobs are
                                dispatched. This may be used to avoid
                                interleaving of output of shell
                                services with the status output on the
                                console.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>RemainAfterExit=</varname></term>

                                <listitem><para>Takes a boolean value
                                that specifies whether the service
                                shall be considered active even when
                                all its processes exited. Defaults to
                                <option>no</option>.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>GuessMainPID=</varname></term>

                                <listitem><para>Takes a boolean value
                                that specifies whether systemd should
                                try to guess the main PID of a service
                                if it cannot be determined
                                reliably. This option is ignored
                                unless <option>Type=forking</option>
                                is set and <option>PIDFile=</option>
                                is unset because for the other types
                                or with an explicitly configured PID
                                file, the main PID is always known. The
                                guessing algorithm might come to
                                incorrect conclusions if a daemon
                                consists of more than one process. If
                                the main PID cannot be determined,
                                failure detection and automatic
                                restarting of a service will not work
                                reliably. Defaults to
                                <option>yes</option>.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>PIDFile=</varname></term>

                                <listitem><para>Takes an absolute file
                                name pointing to the PID file of this
                                daemon. Use of this option is
                                recommended for services where
                                <varname>Type=</varname> is set to
                                <option>forking</option>. systemd will
                                read the PID of the main process of
                                the daemon after start-up of the
                                service. systemd will not write to the
                                file configured here.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>BusName=</varname></term>

                                <listitem><para>Takes a D-Bus bus
                                name that this service is reachable
                                as. This option is mandatory for
                                services where
                                <varname>Type=</varname> is set to
                                <option>dbus</option>, but its use
                                is otherwise recommended if the process
                                takes a name on the D-Bus bus.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ExecStart=</varname></term>
                                <listitem><para>Commands with their
                                arguments that are executed when this
                                service is started. For each of the
                                specified commands, the first argument
                                must be an absolute and literal path
                                to an executable.</para>

                                <para>When <varname>Type</varname> is
                                not <option>oneshot</option>, only one
                                command may be given. When
                                <varname>Type=oneshot</varname> is
                                used, more than one command may be
                                specified. Multiple command lines may
                                be concatenated in a single directive
                                by separating them with semicolons
                                (these semicolons must be passed as
                                separate words). Alternatively, this
                                directive may be specified more than
                                once with the same effect.
                                Lone semicolons may be escaped as
                                <literal>\;</literal>. If the empty
                                string is assigned to this option, the
                                list of commands to start is reset,
                                prior assignments of this option will
                                have no effect.</para>

                                <para>Each command line is split on
                                whitespace, with the first item being
                                the command to execute, and the
                                subsequent items being the arguments.
                                Double quotes ("...") and single
                                quotes ('...') may be used, in which
                                case everything until the next
                                matching quote becomes part of the
                                same argument. Quotes themselves are
                                removed after parsing. In addition, a
                                trailing backslash
                                (<literal>\</literal>) may be used to
                                merge lines. This syntax is intended
                                to be very similar to shell syntax,
                                but only the meta-characters and
                                expansions described in the following
                                paragraphs are understood.
                                Specifically, redirection using
                                <literal>&lt;</literal>,
                                <literal>&lt;&lt;</literal>,
                                <literal>&gt;</literal>, and
                                <literal>&gt;&gt;</literal>, pipes
                                using <literal>|</literal>, and
                                running programs in the background
                                using <literal>&amp;</literal>
                                and <emphasis>other elements of shell
                                syntax are not supported</emphasis>.
                                </para>

                                <para>If more than one command is
                                specified, the commands are invoked
                                sequentially in the order they appear
                                in the unit file. If one of the
                                commands fails (and is not prefixed
                                with <literal>-</literal>), other lines
                                are not executed, and the unit is
                                considered failed.</para>

                                <para>Unless
                                <varname>Type=forking</varname> is
                                set, the process started via this
                                command line will be considered the
                                main process of the daemon.</para>

                                <para>The command line accepts
                                <literal>%</literal> specifiers as
                                described in
                                <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
                                Note that the first argument of the
                                command line (i.e. the program to
                                execute) may not include
                                specifiers.</para>

                                <para>Basic environment variable
                                substitution is supported. Use
                                <literal>${FOO}</literal> as part of a
                                word, or as a word of its own, on the
                                command line, in which case it will be
                                replaced by the value of the
                                environment variable including all
                                whitespace it contains, resulting in a
                                single argument. Use
                                <literal>$FOO</literal> as a separate
                                word on the command line, in which
                                case it will be replaced by the value
                                of the environment variable split at
                                whitespace, resulting in zero or more
                                arguments. To pass a literal dollar
                                sign, use <literal>$$</literal>.
                                Variables whose value is not known at
                                expansion time are treated as empty
                                strings. Note that the first argument
                                (i.e. the program to execute) may not
                                be a variable.</para>

                                <para>Variables to be used in this
                                fashion may be defined through
                                <varname>Environment=</varname> and
                                <varname>EnvironmentFile=</varname>.
                                In addition, variables listed in the
                                section "Environment variables in
                                spawned processes" in
                                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                                which are considered "static
                                configuration", may be used (this includes
                                e.g. <varname>$USER</varname>, but not
                                <varname>$TERM</varname>).</para>

                                <para>Optionally, if the absolute file
                                name is prefixed with
                                <literal>@</literal>, the second token
                                will be passed as
                                <literal>argv[0]</literal> to the
                                executed process, followed by the
                                further arguments specified. If the
                                absolute filename is prefixed with
                                <literal>-</literal>, an exit code of
                                the command normally considered a
                                failure (i.e. non-zero exit status or
                                abnormal exit due to signal) is ignored
                                and considered success. If both
                                <literal>-</literal> and
                                <literal>@</literal> are used, they
                                can appear in either order.</para>

                                <para>Note that this setting does not
                                directly support shell command
                                lines. If shell command lines are to
                                be used, they need to be passed
                                explicitly to a shell implementation
                                of some kind. Example:</para>
                                <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'</programlisting>
                                <para>Example:</para>
                                <programlisting>ExecStart=/bin/echo one ; /bin/echo "two two"</programlisting>
                                <para>This will execute
                                <command>/bin/echo</command> two
                                times, each time with one argument:
                                <literal>one</literal> and
                                <literal>two two</literal>,
                                respectively. Because two commands are
                                specified,
                                <varname>Type=oneshot</varname> must
                                be used.</para>

                                <para>Example:</para>
                                <programlisting>ExecStart=/bin/echo / &gt;/dev/null &amp; \; \
/bin/ls</programlisting>
                                <para>This will execute
                                <command>/bin/echo</command> with five
                                arguments: <literal>/</literal>,
                                <literal>&gt;/dev/null</literal>,
                                <literal>&amp;</literal>,
                                <literal>;</literal>, and
                                <literal>/bin/ls</literal>.</para>

                                <para>Example:</para>
                                <programlisting>Environment="ONE=one" 'TWO=two two'
ExecStart=/bin/echo $ONE $TWO ${TWO}</programlisting>
                                <para>This will execute
                                <command>/bin/echo</command> with four
                                arguments: <literal>one</literal>,
                                <literal>two</literal>,
                                <literal>two</literal>, and
                                <literal>two two</literal>.</para>
                              </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ExecStartPre=</varname></term>
                                <term><varname>ExecStartPost=</varname></term>
                                <listitem><para>Additional commands
                                that are executed before or after
                                the command in
                                <varname>ExecStart=</varname>, respectively.
                                Syntax is the same as for
                                <varname>ExecStart=</varname>, except
                                that multiple command lines are allowed
                                and the commands are executed one
                                after the other, serially.</para>

                                <para>If any of those commands (not
                                prefixed with <literal>-</literal>)
                                fail, the rest are not executed and
                                the unit is considered failed.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ExecReload=</varname></term>
                                <listitem><para>Commands to execute to
                                trigger a configuration reload in the
                                service. This argument takes multiple
                                command lines, following the same
                                scheme as described for
                                <varname>ExecStart=</varname>
                                above. Use of this setting is
                                optional. Specifier and environment
                                variable substitution is supported
                                here following the same scheme as for
                                <varname>ExecStart=</varname>.</para>

                                <para>One additional, special
                                environment variable is set: if known,
                                <varname>$MAINPID</varname> is set to
                                the main process of the daemon, and
                                may be used for command lines like the
                                following:</para>

                                <programlisting>/bin/kill -HUP $MAINPID</programlisting>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ExecStop=</varname></term>
                                <listitem><para>Commands to execute to
                                stop the service started via
                                <varname>ExecStart=</varname>. This
                                argument takes multiple command lines,
                                following the same scheme as described
                                for <varname>ExecStart=</varname>
                                above. Use of this setting is
                                optional. After the commands configured
                                in this option are run, all processes
                                remaining for a service are
                                terminated according to the
                                <varname>KillMode=</varname> setting
                                (see
                                <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
                                this option is not specified, the
                                process is terminated immediately when
                                service stop is requested. Specifier
                                and environment variable substitution
                                is supported (including
                                <varname>$MAINPID</varname>, see
                                above).</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ExecStopPost=</varname></term>
                                <listitem><para>Additional commands
                                that are executed after the service
                                was stopped. This includes cases where
                                the commands configured in
                                <varname>ExecStop=</varname> were used,
                                where the service does not have any
                                <varname>ExecStop=</varname> defined, or
                                where the service exited unexpectedly. This
                                argument takes multiple command lines,
                                following the same scheme as described
                                for <varname>ExecStart</varname>. Use
                                of these settings is
                                optional. Specifier and environment
                                variable substitution is
                                supported.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>RestartSec=</varname></term>
                                <listitem><para>Configures the time to
                                sleep before restarting a service (as
                                configured with
                                <varname>Restart=</varname>). Takes a
                                unit-less value in seconds, or a time
                                span value such as "5min
                                20s". Defaults to
                                100ms.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>TimeoutStartSec=</varname></term>
                                <listitem><para>Configures the time to
                                wait for start-up. If a
                                daemon service does not signal
                                start-up completion within the
                                configured time, the service will be
                                considered failed and will be shut
                                down again.
                                Takes a unit-less value in seconds, or a
                                time span value such as "5min
                                20s". Pass <literal>0</literal> to
                                disable the timeout logic. Defaults to
                                <varname>TimeoutStartSec=</varname> from
                                the manager configuration file, except
                                when <varname>Type=oneshot</varname> is
                                used, in which case the timeout
                                is disabled by default.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>TimeoutStopSec=</varname></term>
                                <listitem><para>Configures the time to
                                wait for stop. If a service is asked
                                to stop, but does not terminate in the
                                specified time, it will be terminated
                                forcibly via <constant>SIGTERM</constant>,
                                and after another timeout of equal duration
                                with <constant>SIGKILL</constant> (see
                                <varname>KillMode=</varname>
                                in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
                                Takes a unit-less value in seconds, or a
                                time span value such as "5min
                                20s". Pass <literal>0</literal> to disable
                                the timeout logic. Defaults to
                                <varname>TimeoutStartSec=</varname> from the
                                manager configuration file.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>TimeoutSec=</varname></term>
                                <listitem><para>A shorthand for configuring
                                both <varname>TimeoutStartSec=</varname>
                                and <varname>TimeoutStopSec=</varname>
                                to the specified value.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>WatchdogSec=</varname></term>
                                <listitem><para>Configures the
                                watchdog timeout for a service. The
                                watchdog is activated when the start-up is
                                completed. The service must call
                                <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                regularly with <literal>WATCHDOG=1</literal>
                                (i.e. the "keep-alive ping"). If the time
                                between two such calls is larger than
                                the configured time, then the service
                                is placed in a failed state. By
                                setting <varname>Restart=</varname> to
                                <option>on-failure</option> or
                                <option>always</option>, the service
                                will be automatically restarted. The
                                time configured here will be passed to
                                the executed service process in the
                                <varname>WATCHDOG_USEC=</varname>
                                environment variable. This allows
                                daemons to automatically enable the
                                keep-alive pinging logic if watchdog
                                support is enabled for the service. If
                                this option is used,
                                <varname>NotifyAccess=</varname> (see
                                below) should be set to open access to
                                the notification socket provided by
                                systemd. If
                                <varname>NotifyAccess=</varname> is
                                not set, it will be implicitly set to
                                <option>main</option>. Defaults to 0,
                                which disables this
                                feature.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>Restart=</varname></term>
                                <listitem><para>Configures whether the
                                service shall be restarted when the
                                service process exits, is killed,
                                or a timeout is reached. The service
                                process may be the main service
                                process, but it may also be one of the
                                processes specified with
                                <varname>ExecStartPre=</varname>,
                                <varname>ExecStartPost=</varname>,
                                <varname>ExecStopPre=</varname>,
                                <varname>ExecStopPost=</varname>, or
                                <varname>ExecReload=</varname>.
                                When the death of the process is a
                                result of systemd operation (e.g. service
                                stop or restart), the service will not be
                                restarted. Timeouts include missing
                                the watchdog "keep-alive ping"
                                deadline and a service start, reload,
                                and stop operation timeouts.</para>

                                <para>Takes one of
                                <option>no</option>,
                                <option>on-success</option>,
                                <option>on-failure</option>,
                                <option>on-watchdog</option>,
                                <option>on-abort</option>, or
                                <option>always</option>. If set to
                                <option>no</option> (the default), the
                                service will not be restarted. If set to
                                <option>on-success</option>, it will be
                                restarted only when the service process
                                exits cleanly.
                                In this context, a clean exit means
                                an exit code of 0, or one of the signals
                                <constant>SIGHUP</constant>,
                                <constant>SIGINT</constant>,
                                <constant>SIGTERM</constant>,
                                or <constant>SIGPIPE</constant>, and
                                additionally, exit statuses and signals
                                specified in <varname>SuccessExitStatus=</varname>.
                                If set to <option>on-failure</option>,
                                the service will be restarted when the
                                process exits with a non-zero exit code,
                                is terminated by a signal (including on
                                core dump), when an operation (such as
                                service reload) times out, and when the
                                configured watchdog timeout is triggered.
                                If set to
                                <option>on-abort</option>, the service
                                will be restarted only if the service
                                process exits due to an uncaught
                                signal not specified as a clean exit
                                status.
                                If set to
                                <option>on-watchdog</option>, the service
                                will be restarted only if the watchdog
                                timeout for the service expires.
                                If set to
                                <option>always</option>, the service
                                will be restarted regardless of whether
                                it exited cleanly or not, got
                                terminated abnormally by a signal, or
                                hit a timeout.</para>

                                <para>In addition to the above settings,
                                the service will not be restarted if the
                                exit code or signal is specified in
                                <varname>RestartPreventExitStatus=</varname>
                                (see below).</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>SuccessExitStatus=</varname></term>
                                <listitem><para>Takes a list of exit
                                status definitions that when returned
                                by the main service process will be
                                considered successful termination, in
                                addition to the normal successful exit
                                code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
                                <constant>SIGTERM</constant>, and <constant>SIGPIPE</constant>. Exit status
                                definitions can either be numeric exit
                                codes or termination signal names,
                                separated by spaces. Signals will only
                                be considered if the service does not implement
                                a signal handler and exits as a direct result
                                of receiving the signal. For example:
				<programlisting>SuccessExitStatus=1 2 8 <constant>SIGKILL</constant></programlisting>
				ensures that exit codes 1, 2, 8 and
				the termination signal
				<constant>SIGKILL</constant> are
				considered clean service terminations.
			        </para>

				<para>Note that if a process has a
				signal handler installed and exits by
				calling
				<citerefentry><refentrytitle>_exit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
				in response to a signal, the
				information about the signal is lost.
				Programs should instead perform cleanup and kill themselves with the same signal instead. See
				<ulink url="http://www.cons.org/cracauer/sigint.html">Proper handling of SIGINT/SIGQUIT — How to be a proper program</ulink>.</para>

				<para>This option may appear more than once
				in which case the list of successful
				exit statuses is merged. If the empty
				string is assigned to this option, the
				list is reset, all prior assignments
				of this option will have no
				effect.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>RestartPreventExitStatus=</varname></term>
                                <listitem><para>Takes a list of exit
                                status definitions that when returned
                                by the main service process will
                                prevent automatic service restarts,
                                regardless of the restart setting
                                configured with
                                <varname>Restart=</varname>. Exit
                                status definitions can either be
                                numeric exit codes or termination
                                signal names, and are separated by
                                spaces. Defaults to the empty list, so
                                that, by default, no exit status is
                                excluded from the configured restart
                                logic. Example:
                                <literal>RestartPreventExitStatus=1 6
                                SIGABRT</literal>, ensures that exit
                                codes 1 and 6 and the termination
                                signal <constant>SIGABRT</constant> will
                                not result in automatic service
                                restarting. This
                                option may appear more than once, in
                                which case the list of restart-preventing
                                statuses is merged. If the empty
                                string is assigned to this option, the
                                list is reset and all prior assignments
                                of this option will have no
                                effect.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>PermissionsStartOnly=</varname></term>
                                <listitem><para>Takes a boolean
                                argument. If true, the permission-related
                                execution options, as
                                configured with
                                <varname>User=</varname> and similar
                                options (see
                                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                for more information), are only applied
                                to the process started with
                                <varname>ExecStart=</varname>, and not
                                to the various other
                                <varname>ExecStartPre=</varname>,
                                <varname>ExecStartPost=</varname>,
                                <varname>ExecReload=</varname>,
                                <varname>ExecStop=</varname>, and
                                <varname>ExecStopPost=</varname>
                                commands. If false, the setting is
                                applied to all configured commands the
                                same way. Defaults to
                                false.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>RootDirectoryStartOnly=</varname></term>
                                <listitem><para>Takes a boolean
                                argument. If true, the root directory,
                                as configured with the
                                <varname>RootDirectory=</varname>
                                option (see
                                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                for more information), is only applied
                                to the process started with
                                <varname>ExecStart=</varname>, and not
                                to the various other
                                <varname>ExecStartPre=</varname>,
                                <varname>ExecStartPost=</varname>,
                                <varname>ExecReload=</varname>,
                                <varname>ExecStop=</varname>, and
                                <varname>ExecStopPost=</varname>
                                commands. If false, the setting is
                                applied to all configured commands the
                                same way. Defaults to
                                false.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>NonBlocking=</varname></term>
                                <listitem><para>Set the
                                <constant>O_NONBLOCK</constant> flag
                                for all file descriptors passed via
                                socket-based activation. If true, all
                                file descriptors >= 3 (i.e. all except
                                STDIN/STDOUT/STDERR) will have
                                the <constant>O_NONBLOCK</constant> flag
                                set and hence are in
                                non-blocking mode. This option is only
                                useful in conjunction with a socket
                                unit, as described in
                                <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
                                to false.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>NotifyAccess=</varname></term>
                                <listitem><para>Controls access to the
                                service status notification socket, as
                                accessible via the
                                <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                call. Takes one of
                                <option>none</option> (the default),
                                <option>main</option> or
                                <option>all</option>. If
                                <option>none</option>, no daemon status
                                updates are accepted from the service
                                processes, all status update messages
                                are ignored. If <option>main</option>,
                                only service updates sent from the
                                main process of the service are
                                accepted. If <option>all</option>, all
                                services updates from all members of
                                the service's control group are
                                accepted. This option should be set to
                                open access to the notification socket
                                when using
                                <varname>Type=notify</varname> or
                                <varname>WatchdogSec=</varname> (see
                                above). If those options are used but
                                <varname>NotifyAccess=</varname> is not
                                configured, it will be implicitly set
                                to
                                <option>main</option>.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>Sockets=</varname></term>
                                <listitem><para>Specifies the name of
                                the socket units this service shall
                                inherit the sockets from when the
                                service is started. Normally it
                                should not be necessary to use this
                                setting as all sockets whose unit
                                shares the same name as the service
                                (ignoring the different suffix of course)
                                are passed to the spawned
                                process.</para>

                                <para>Note that the same socket may be
                                passed to multiple processes at the
                                same time. Also note that a different
                                service may be activated on incoming
                                traffic than that which inherits the
                                sockets. Or in other words: the
                                <varname>Service=</varname> setting of
                                <filename>.socket</filename> units
                                does not have to match the inverse of
                                the <varname>Sockets=</varname>
                                setting of the
                                <filename>.service</filename> it
                                refers to.</para>

                                <para>This option may appear more than
                                once, in which case the list of socket
                                units is merged. If the empty string
                                is assigned to this option, the list of
                                sockets is reset, and all prior uses of
                                this setting will have no
                                effect.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>StartLimitInterval=</varname></term>
                                <term><varname>StartLimitBurst=</varname></term>

                                <listitem><para>Configure service
                                start rate limiting. By default,
                                services which are started more
                                than 5 times within 10 seconds are not
                                permitted to start any more times
                                until the 10 second interval ends. With
                                these two options, this rate limiting
                                may be modified. Use
                                <varname>StartLimitInterval=</varname>
                                to configure the checking interval (defaults to
                                <varname>DefaultStartLimitInterval=</varname> in
                                manager configuration file, set to 0 to disable
                                any kind of rate limiting). Use
                                <varname>StartLimitBurst=</varname> to
                                configure how many starts per interval
                                are allowed (defaults to
                                <varname>DefaultStartLimitBurst=</varname> in
                                manager configuration file). These
                                configuration options are particularly
                                useful in conjunction with
                                <varname>Restart=</varname>; however,
                                they apply to all kinds of starts
                                (including manual), not just those
                                triggered by the
                                <varname>Restart=</varname> logic.
                                Note that units which are configured
                                for <varname>Restart=</varname> and
                                which reach the start limit are not
                                attempted to be restarted anymore;
                                however, they may still be restarted
                                manually at a later point, from which
                                point on, the restart logic is again
                                activated. Note that
                                <command>systemctl
                                reset-failed</command> will cause the
                                restart rate counter for a service to
                                be flushed, which is useful if the
                                administrator wants to manually start
                                a service and the start limit
                                interferes with
                                that.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>StartLimitAction=</varname></term>

                                <listitem><para>Configure the action
                                to take if the rate limit configured
                                with
                                <varname>StartLimitInterval=</varname>
                                and
                                <varname>StartLimitBurst=</varname> is
                                hit. Takes one of
                                <option>none</option>,
                                <option>reboot</option>,
                                <option>reboot-force</option>, or
                                <option>reboot-immediate</option>. If
                                <option>none</option> is set,
                                hitting the rate limit will trigger no
                                action besides that the start will not
                                be permitted. <option>reboot</option>
                                causes a reboot following the normal
                                shutdown procedure (i.e. equivalent to
                                <command>systemctl reboot</command>).
                                <option>reboot-force</option> causes
                                a forced reboot which will terminate
                                all processes forcibly but should
                                cause no dirty file systems on reboot
                                (i.e. equivalent to <command>systemctl
                                reboot -f</command>) and
                                <option>reboot-immediate</option>
                                causes immediate execution of the
                                <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                                system call, which might result in
                                data loss. Defaults to
                                <option>none</option>.</para></listitem>
                        </varlistentry>

                </variablelist>

                <para>Check
                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                and
                <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                for more settings.</para>

        </refsect1>

        <refsect1>
                <title>Compatibility Options</title>

                <para>The following options are also available in the
                <literal>[Service]</literal> section, but exist purely
                for compatibility reasons and should not be used in
                newly written service files.</para>

                <variablelist class='unit-directives'>
                        <varlistentry>
                                <term><varname>SysVStartPriority=</varname></term>
                                <listitem><para>Set the SysV start
                                priority to use to order this service
                                in relation to SysV services lacking
                                LSB headers. This option is only
                                necessary to fix ordering in relation
                                to legacy SysV services that have no
                                ordering information encoded in the
                                script headers. As such, it should only
                                be used as a temporary compatibility
                                option and should not be used in new unit
                                files. Almost always, it is a better
                                choice to add explicit ordering
                                directives via
                                <varname>After=</varname> or
                                <varname>Before=</varname>,
                                instead. For more details, see
                                <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
                                If used, pass an integer value in the
                                range 0-99.</para></listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                  <title>See Also</title>
                  <para>
                          <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                  </para>
        </refsect1>

</refentry>