man/systemd.exec.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.
  20
  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.exec">
  26         <refentryinfo>
  27                 <title>systemd.exec</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.exec</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.exec</refname>
  47                 <refpurpose>Execution environment configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename>,
  52                 <filename>systemd.socket</filename>,
  53                 <filename>systemd.mount</filename>,
  54                 <filename>systemd.swap</filename></para>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para>Unit configuration files for services, sockets,
  61                 mount points and swap devices share a subset of
  62                 configuration options which define the execution
  63                 environment of spawned processes.</para>
  64
  65                 <para>This man page lists the configuration options
  66                 shared by these four unit types. See
  67                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  68                 for the common options of all unit configuration
  69                 files, and
  70                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  71                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  72                 <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  73                 and
  74                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  75                 for more information on the specific unit
  76                 configuration files. The execution specific
  77                 configuration options are configured in the [Service],
  78                 [Socket], [Mount], or [Swap] sections, depending on the unit
  79                 type.</para>
  80         </refsect1>
  81
  82         <refsect1>
  83                 <title>Options</title>
  84
  85                 <variablelist>
  86
  87                         <varlistentry>
  88                                 <term><varname>WorkingDirectory=</varname></term>
  89
  90                                 <listitem><para>Takes an absolute
  91                                 directory path. Sets the working
  92                                 directory for executed processes. If
  93                                 not set defaults to the root directory
  94                                 when systemd is running as a system
  95                                 instance and the respective user's
  96                                 home directory if run as
  97                                 user.</para></listitem>
  98                         </varlistentry>
  99
 100                         <varlistentry>
 101                                 <term><varname>RootDirectory=</varname></term>
 102
 103                                 <listitem><para>Takes an absolute
 104                                 directory path. Sets the root
 105                                 directory for executed processes, with
 106                                 the
 107                                 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 108                                 system call. If this is used it must
 109                                 be ensured that the process and all
 110                                 its auxiliary files are available in
 111                                 the <function>chroot()</function>
 112                                 jail.</para></listitem>
 113                         </varlistentry>
 114
 115                         <varlistentry>
 116                                 <term><varname>User=</varname></term>
 117                                 <term><varname>Group=</varname></term>
 118
 119                                 <listitem><para>Sets the Unix user
 120                                 or group that the processes are executed
 121                                 as, respectively. Takes a single user or group
 122                                 name or ID as argument. If no group is
 123                                 set, the default group of the user is
 124                                 chosen.</para></listitem>
 125                         </varlistentry>
 126
 127                         <varlistentry>
 128                                 <term><varname>SupplementaryGroups=</varname></term>
 129
 130                                 <listitem><para>Sets the supplementary
 131                                 Unix groups the processes are executed
 132                                 as. This takes a space separated list
 133                                 of group names or IDs. This option may
 134                                 be specified more than once in which
 135                                 case all listed groups are set as
 136                                 supplementary groups. When the empty
 137                                 string is assigned the list of
 138                                 supplementary groups is reset, and all
 139                                 assignments prior to this one will
 140                                 have no effect. In any way, this
 141                                 option does not override, but extends
 142                                 the list of supplementary groups
 143                                 configured in the system group
 144                                 database for the
 145                                 user.</para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><varname>Nice=</varname></term>
 150
 151                                 <listitem><para>Sets the default nice
 152                                 level (scheduling priority) for
 153                                 executed processes. Takes an integer
 154                                 between -20 (highest priority) and 19
 155                                 (lowest priority). See
 156                                 <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 157                                 for details.</para></listitem>
 158                         </varlistentry>
 159
 160                         <varlistentry>
 161                                 <term><varname>OOMScoreAdjust=</varname></term>
 162
 163                                 <listitem><para>Sets the adjustment
 164                                 level for the Out-Of-Memory killer for
 165                                 executed processes. Takes an integer
 166                                 between -1000 (to disable OOM killing
 167                                 for this process) and 1000 (to make
 168                                 killing of this process under memory
 169                                 pressure very likely). See <ulink
 170                                 url="http://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
 171                                 for details.</para></listitem>
 172                         </varlistentry>
 173
 174                         <varlistentry>
 175                                 <term><varname>IOSchedulingClass=</varname></term>
 176
 177                                 <listitem><para>Sets the IO scheduling
 178                                 class for executed processes. Takes an
 179                                 integer between 0 and 3 or one of the
 180                                 strings <option>none</option>,
 181                                 <option>realtime</option>,
 182                                 <option>best-effort</option> or
 183                                 <option>idle</option>. See
 184                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 185                                 for details.</para></listitem>
 186                         </varlistentry>
 187
 188                         <varlistentry>
 189                                 <term><varname>IOSchedulingPriority=</varname></term>
 190
 191                                 <listitem><para>Sets the IO scheduling
 192                                 priority for executed processes. Takes
 193                                 an integer between 0 (highest
 194                                 priority) and 7 (lowest priority). The
 195                                 available priorities depend on the
 196                                 selected IO scheduling class (see
 197                                 above). See
 198                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 199                                 for details.</para></listitem>
 200                         </varlistentry>
 201
 202                         <varlistentry>
 203                                 <term><varname>CPUSchedulingPolicy=</varname></term>
 204
 205                                 <listitem><para>Sets the CPU
 206                                 scheduling policy for executed
 207                                 processes. Takes one of
 208                                 <option>other</option>,
 209                                 <option>batch</option>,
 210                                 <option>idle</option>,
 211                                 <option>fifo</option> or
 212                                 <option>rr</option>. See
 213                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 214                                 for details.</para></listitem>
 215                         </varlistentry>
 216
 217                         <varlistentry>
 218                                 <term><varname>CPUSchedulingPriority=</varname></term>
 219
 220                                 <listitem><para>Sets the CPU
 221                                 scheduling priority for executed
 222                                 processes. The available priority
 223                                 range depends on the selected CPU
 224                                 scheduling policy (see above). For
 225                                 real-time scheduling policies an
 226                                 integer between 1 (lowest priority)
 227                                 and 99 (highest priority) can be used.
 228                                 See <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 229                                 for details.
 230                                 </para></listitem>
 231                         </varlistentry>
 232
 233                         <varlistentry>
 234                                 <term><varname>CPUSchedulingResetOnFork=</varname></term>
 235
 236                                 <listitem><para>Takes a boolean
 237                                 argument. If true elevated CPU
 238                                 scheduling priorities and policies
 239                                 will be reset when the executed
 240                                 processes fork, and can hence not leak
 241                                 into child processes. See
 242                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 243                                 for details. Defaults to false.</para></listitem>
 244                         </varlistentry>
 245
 246                         <varlistentry>
 247                                 <term><varname>CPUAffinity=</varname></term>
 248
 249                                 <listitem><para>Controls the CPU
 250                                 affinity of the executed
 251                                 processes. Takes a space-separated
 252                                 list of CPU indexes. This option may
 253                                 be specified more than once in which
 254                                 case the specificed CPU affinity masks
 255                                 are merged. If the empty string is
 256                                 assigned the mask is reset, all
 257                                 assignments prior to this will have no
 258                                 effect. See
 259                                 <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 260                                 for details.</para></listitem>
 261                         </varlistentry>
 262
 263                         <varlistentry>
 264                                 <term><varname>UMask=</varname></term>
 265
 266                                 <listitem><para>Controls the file mode
 267                                 creation mask. Takes an access mode in
 268                                 octal notation. See
 269                                 <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 270                                 for details. Defaults to
 271                                 0022.</para></listitem>
 272                         </varlistentry>
 273
 274                         <varlistentry>
 275                                 <term><varname>Environment=</varname></term>
 276
 277                                 <listitem><para>Sets environment
 278                                 variables for executed
 279                                 processes. Takes a space-separated
 280                                 list of variable assignments. This
 281                                 option may be specified more than once
 282                                 in which case all listed variables
 283                                 will be set. If the same variable is
 284                                 set twice the later setting will
 285                                 override the earlier setting. If the
 286                                 empty string is assigned to this
 287                                 option the list of environment
 288                                 variables is reset, all prior
 289                                 assignments have no effect. See
 290                                 <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 291                                 for details.</para></listitem>
 292                         </varlistentry>
 293                         <varlistentry>
 294                                 <term><varname>EnvironmentFile=</varname></term>
 295                                 <listitem><para>Similar to
 296                                 <varname>Environment=</varname> but
 297                                 reads the environment variables from a
 298                                 text file. The text file should
 299                                 contain new-line separated variable
 300                                 assignments. Empty lines and lines
 301                                 starting with ; or # will be ignored,
 302                                 which may be used for commenting. The
 303                                 parser strips leading and
 304                                 trailing whitespace from the values
 305                                 of assignments, unless you use
 306                                 double quotes (").</para>
 307
 308                                 <para>The argument passed should be an
 309                                 absolute file name or wildcard
 310                                 expression, optionally prefixed with
 311                                 "-", which indicates that if the file
 312                                 does not exist it won't be read and no
 313                                 error or warning message is logged.
 314                                 This option may be specified more than
 315                                 once in which case all specified files
 316                                 are read. If the empty string is
 317                                 assigned to this option the list of
 318                                 file to read is reset, all prior
 319                                 assignments have no effect.</para>
 320
 321                                 <para>The files listed with this
 322                                 directive will be read shortly before
 323                                 the process is executed. Settings from
 324                                 these files override settings made
 325                                 with
 326                                 <varname>Environment=</varname>. If
 327                                 the same variable is set twice from
 328                                 these files the files will be read in
 329                                 the order they are specified and the
 330                                 later setting will override the
 331                                 earlier setting.</para></listitem>
 332                         </varlistentry>
 333
 334                         <varlistentry>
 335                                 <term><varname>StandardInput=</varname></term>
 336                                 <listitem><para>Controls where file
 337                                 descriptor 0 (STDIN) of the executed
 338                                 processes is connected to. Takes one
 339                                 of <option>null</option>,
 340                                 <option>tty</option>,
 341                                 <option>tty-force</option>,
 342                                 <option>tty-fail</option> or
 343                                 <option>socket</option>. If
 344                                 <option>null</option> is selected
 345                                 standard input will be connected to
 346                                 <filename>/dev/null</filename>,
 347                                 i.e. all read attempts by the process
 348                                 will result in immediate EOF. If
 349                                 <option>tty</option> is selected
 350                                 standard input is connected to a TTY
 351                                 (as configured by
 352                                 <varname>TTYPath=</varname>, see
 353                                 below) and the executed process
 354                                 becomes the controlling process of the
 355                                 terminal. If the terminal is already
 356                                 being controlled by another process the
 357                                 executed process waits until the current
 358                                 controlling process releases the
 359                                 terminal.
 360                                 <option>tty-force</option>
 361                                 is similar to <option>tty</option>,
 362                                 but the executed process is forcefully
 363                                 and immediately made the controlling
 364                                 process of the terminal, potentially
 365                                 removing previous controlling
 366                                 processes from the
 367                                 terminal. <option>tty-fail</option> is
 368                                 similar to <option>tty</option> but if
 369                                 the terminal already has a controlling
 370                                 process start-up of the executed
 371                                 process fails.  The
 372                                 <option>socket</option> option is only
 373                                 valid in socket-activated services,
 374                                 and only when the socket configuration
 375                                 file (see
 376                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 377                                 for details) specifies a single socket
 378                                 only. If this option is set standard
 379                                 input will be connected to the socket
 380                                 the service was activated from, which
 381                                 is primarily useful for compatibility
 382                                 with daemons designed for use with the
 383                                 traditional
 384                                 <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 385                                 daemon. This setting defaults to
 386                                 <option>null</option>.</para></listitem>
 387                         </varlistentry>
 388                         <varlistentry>
 389                                 <term><varname>StandardOutput=</varname></term>
 390                                 <listitem><para>Controls where file
 391                                 descriptor 1 (STDOUT) of the executed
 392                                 processes is connected to. Takes one
 393                                 of <option>inherit</option>,
 394                                 <option>null</option>,
 395                                 <option>tty</option>,
 396                                 <option>syslog</option>,
 397                                 <option>kmsg</option>,
 398                                 <option>journal</option>,
 399                                 <option>syslog+console</option>,
 400                                 <option>kmsg+console</option>,
 401                                 <option>journal+console</option> or
 402                                 <option>socket</option>. If set to
 403                                 <option>inherit</option> the file
 404                                 descriptor of standard input is
 405                                 duplicated for standard output. If set
 406                                 to <option>null</option> standard
 407                                 output will be connected to
 408                                 <filename>/dev/null</filename>,
 409                                 i.e. everything written to it will be
 410                                 lost. If set to <option>tty</option>
 411                                 standard output will be connected to a
 412                                 tty (as configured via
 413                                 <varname>TTYPath=</varname>, see
 414                                 below). If the TTY is used for output
 415                                 only the executed process will not
 416                                 become the controlling process of the
 417                                 terminal, and will not fail or wait
 418                                 for other processes to release the
 419                                 terminal. <option>syslog</option>
 420                                 connects standard output to the
 421                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 422                                 system syslog
 423                                 service. <option>kmsg</option>
 424                                 connects it with the kernel log buffer
 425                                 which is accessible via
 426                                 <citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>journal</option>
 427                                 connects it with the journal which is
 428                                 accessible via
 429                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 430                                 (Note that everything that is written
 431                                 to syslog or kmsg is implicitly stored
 432                                 in the journal as well, those options
 433                                 are hence supersets of this
 434                                 one). <option>syslog+console</option>,
 435                                 <option>journal+console</option> and
 436                                 <option>kmsg+console</option> work
 437                                 similarly but copy the output to the
 438                                 system console as
 439                                 well. <option>socket</option> connects
 440                                 standard output to a socket from
 441                                 socket activation, semantics are
 442                                 similar to the respective option of
 443                                 <varname>StandardInput=</varname>.
 444                                 This setting defaults to the value set
 445                                 with
 446                                 <option>DefaultStandardOutput=</option>
 447                                 in
 448                                 <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 449                                 which defaults to
 450                                 <option>journal</option>.</para></listitem>
 451                         </varlistentry>
 452                         <varlistentry>
 453                                 <term><varname>StandardError=</varname></term>
 454                                 <listitem><para>Controls where file
 455                                 descriptor 2 (STDERR) of the executed
 456                                 processes is connected to. The
 457                                 available options are identical to
 458                                 those of
 459                                 <varname>StandardOutput=</varname>,
 460                                 with one exception: if set to
 461                                 <option>inherit</option> the file
 462                                 descriptor used for standard output is
 463                                 duplicated for standard error. This
 464                                 setting defaults to the value set with
 465                                 <option>DefaultStandardError=</option>
 466                                 in
 467                                 <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 468                                 which defaults to
 469                                 <option>inherit</option>.</para></listitem>
 470                         </varlistentry>
 471                         <varlistentry>
 472                                 <term><varname>TTYPath=</varname></term>
 473                                 <listitem><para>Sets the terminal
 474                                 device node to use if standard input,
 475                                 output or stderr are connected to a
 476                                 TTY (see above). Defaults to
 477                                 <filename>/dev/console</filename>.</para></listitem>
 478                         </varlistentry>
 479                         <varlistentry>
 480                                 <term><varname>TTYReset=</varname></term>
 481                                 <listitem><para>Reset the terminal
 482                                 device specified with
 483                                 <varname>TTYPath=</varname> before and
 484                                 after execution. Defaults to
 485                                 <literal>no</literal>.</para></listitem>
 486                         </varlistentry>
 487                         <varlistentry>
 488                                 <term><varname>TTYVHangup=</varname></term>
 489                                 <listitem><para>Disconnect all clients
 490                                 which have opened the terminal device
 491                                 specified with
 492                                 <varname>TTYPath=</varname>
 493                                 before and after execution. Defaults
 494                                 to
 495                                 <literal>no</literal>.</para></listitem>
 496                         </varlistentry>
 497                         <varlistentry>
 498                                 <term><varname>TTYVTDisallocate=</varname></term>
 499                                 <listitem><para>If the terminal
 500                                 device specified with
 501                                 <varname>TTYPath=</varname> is a
 502                                 virtual console terminal try to
 503                                 deallocate the TTY before and after
 504                                 execution. This ensures that the
 505                                 screen and scrollback buffer is
 506                                 cleared. Defaults to
 507                                 <literal>no</literal>.</para></listitem>
 508                         </varlistentry>
 509                         <varlistentry>
 510                                 <term><varname>SyslogIdentifier=</varname></term>
 511                                 <listitem><para>Sets the process name
 512                                 to prefix log lines sent to syslog or
 513                                 the kernel log buffer with. If not set
 514                                 defaults to the process name of the
 515                                 executed process. This option is only
 516                                 useful when
 517                                 <varname>StandardOutput=</varname> or
 518                                 <varname>StandardError=</varname> are
 519                                 set to <option>syslog</option> or
 520                                 <option>kmsg</option>.</para></listitem>
 521                         </varlistentry>
 522                         <varlistentry>
 523                                 <term><varname>SyslogFacility=</varname></term>
 524                                 <listitem><para>Sets the syslog
 525                                 facility to use when logging to
 526                                 syslog. One of <option>kern</option>,
 527                                 <option>user</option>,
 528                                 <option>mail</option>,
 529                                 <option>daemon</option>,
 530                                 <option>auth</option>,
 531                                 <option>syslog</option>,
 532                                 <option>lpr</option>,
 533                                 <option>news</option>,
 534                                 <option>uucp</option>,
 535                                 <option>cron</option>,
 536                                 <option>authpriv</option>,
 537                                 <option>ftp</option>,
 538                                 <option>local0</option>,
 539                                 <option>local1</option>,
 540                                 <option>local2</option>,
 541                                 <option>local3</option>,
 542                                 <option>local4</option>,
 543                                 <option>local5</option>,
 544                                 <option>local6</option> or
 545                                 <option>local7</option>. See
 546                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 547                                 for details. This option is only
 548                                 useful when
 549                                 <varname>StandardOutput=</varname> or
 550                                 <varname>StandardError=</varname> are
 551                                 set to <option>syslog</option>.
 552                                 Defaults to
 553                                 <option>daemon</option>.</para></listitem>
 554                         </varlistentry>
 555                         <varlistentry>
 556                                 <term><varname>SyslogLevel=</varname></term>
 557                                 <listitem><para>Default syslog level
 558                                 to use when logging to syslog or the
 559                                 kernel log buffer. One of
 560                                 <option>emerg</option>,
 561                                 <option>alert</option>,
 562                                 <option>crit</option>,
 563                                 <option>err</option>,
 564                                 <option>warning</option>,
 565                                 <option>notice</option>,
 566                                 <option>info</option>,
 567                                 <option>debug</option>. See
 568                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 569                                 for details. This option is only
 570                                 useful when
 571                                 <varname>StandardOutput=</varname> or
 572                                 <varname>StandardError=</varname> are
 573                                 set to <option>syslog</option> or
 574                                 <option>kmsg</option>. Note that
 575                                 individual lines output by the daemon
 576                                 might be prefixed with a different log
 577                                 level which can be used to override
 578                                 the default log level specified
 579                                 here. The interpretation of these
 580                                 prefixes may be disabled with
 581                                 <varname>SyslogLevelPrefix=</varname>,
 582                                 see below. For details see
 583                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 584
 585                                 Defaults to
 586                                 <option>info</option>.</para></listitem>
 587                         </varlistentry>
 588
 589                         <varlistentry>
 590                                 <term><varname>SyslogLevelPrefix=</varname></term>
 591                                 <listitem><para>Takes a boolean
 592                                 argument. If true and
 593                                 <varname>StandardOutput=</varname> or
 594                                 <varname>StandardError=</varname> are
 595                                 set to <option>syslog</option>,
 596                                 <option>kmsg</option> or
 597                                 <option>journal</option>, log lines
 598                                 written by the executed process that
 599                                 are prefixed with a log level will be
 600                                 passed on to syslog with this log
 601                                 level set but the prefix removed. If
 602                                 set to false, the interpretation of
 603                                 these prefixes is disabled and the
 604                                 logged lines are passed on as-is. For
 605                                 details about this prefixing see
 606                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 607                                 Defaults to true.</para></listitem>
 608                         </varlistentry>
 609
 610                         <varlistentry>
 611                                 <term><varname>TimerSlackNSec=</varname></term>
 612                                 <listitem><para>Sets the timer slack
 613                                 in nanoseconds for the executed
 614                                 processes. The timer slack controls
 615                                 the accuracy of wake-ups triggered by
 616                                 timers. See
 617                                 <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 618                                 for more information. Note that in
 619                                 contrast to most other time span
 620                                 definitions this parameter takes an
 621                                 integer value in nano-seconds if no
 622                                 unit is specified. The usual time
 623                                 units are understood
 624                                 too.</para></listitem>
 625                         </varlistentry>
 626
 627                         <varlistentry>
 628                                 <term><varname>LimitCPU=</varname></term>
 629                                 <term><varname>LimitFSIZE=</varname></term>
 630                                 <term><varname>LimitDATA=</varname></term>
 631                                 <term><varname>LimitSTACK=</varname></term>
 632                                 <term><varname>LimitCORE=</varname></term>
 633                                 <term><varname>LimitRSS=</varname></term>
 634                                 <term><varname>LimitNOFILE=</varname></term>
 635                                 <term><varname>LimitAS=</varname></term>
 636                                 <term><varname>LimitNPROC=</varname></term>
 637                                 <term><varname>LimitMEMLOCK=</varname></term>
 638                                 <term><varname>LimitLOCKS=</varname></term>
 639                                 <term><varname>LimitSIGPENDING=</varname></term>
 640                                 <term><varname>LimitMSGQUEUE=</varname></term>
 641                                 <term><varname>LimitNICE=</varname></term>
 642                                 <term><varname>LimitRTPRIO=</varname></term>
 643                                 <term><varname>LimitRTTIME=</varname></term>
 644                                 <listitem><para>These settings control
 645                                 various resource limits for executed
 646                                 processes. See
 647                                 <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 648                                 for details. Use the string
 649                                 <varname>infinity</varname> to
 650                                 configure no limit on a specific
 651                                 resource.</para></listitem>
 652                         </varlistentry>
 653
 654                         <varlistentry>
 655                                 <term><varname>PAMName=</varname></term>
 656                                 <listitem><para>Sets the PAM service
 657                                 name to set up a session as. If set
 658                                 the executed process will be
 659                                 registered as a PAM session under the
 660                                 specified service name. This is only
 661                                 useful in conjunction with the
 662                                 <varname>User=</varname> setting. If
 663                                 not set no PAM session will be opened
 664                                 for the executed processes. See
 665                                 <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 666                                 for details.</para></listitem>
 667                         </varlistentry>
 668
 669                         <varlistentry>
 670                                 <term><varname>TCPWrapName=</varname></term>
 671                                 <listitem><para>If this is a
 672                                 socket-activated service this sets the
 673                                 tcpwrap service name to check the
 674                                 permission for the current connection
 675                                 with. This is only useful in
 676                                 conjunction with socket-activated
 677                                 services, and stream sockets (TCP) in
 678                                 particular. It has no effect on other
 679                                 socket types (e.g. datagram/UDP) and
 680                                 on processes unrelated to socket-based
 681                                 activation. If the tcpwrap
 682                                 verification fails daemon start-up
 683                                 will fail and the connection is
 684                                 terminated. See
 685                                 <citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 686                                 for details. Note that this option may
 687                                 be used to do access control checks
 688                                 only. Shell commands and commands
 689                                 described in
 690                                 <citerefentry><refentrytitle>hosts_options</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 691                                 are not supported.</para></listitem>
 692                         </varlistentry>
 693
 694                         <varlistentry>
 695                                 <term><varname>CapabilityBoundingSet=</varname></term>
 696
 697                                 <listitem><para>Controls which
 698                                 capabilities to include in the
 699                                 capability bounding set for the
 700                                 executed process. See
 701                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 702                                 for details. Takes a whitespace
 703                                 separated list of capability names as
 704                                 read by
 705                                 <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 706                                 Capabilities listed will be included
 707                                 in the bounding set, all others are
 708                                 removed. If the list of capabilities
 709                                 is prefixed with ~ all but the listed
 710                                 capabilities will be included, the
 711                                 effect of the assignment
 712                                 inverted. Note that this option also
 713                                 effects the respective capabilities in
 714                                 the effective, permitted and
 715                                 inheritable capability sets, on top of
 716                                 what <varname>Capabilities=</varname>
 717                                 does. If this option is not used the
 718                                 capability bounding set is not
 719                                 modified on process execution, hence
 720                                 no limits on the capabilities of the
 721                                 process are enforced. This option may
 722                                 appear more than once in which case
 723                                 the bounding sets are merged. If the empty
 724                                 string is assigned to this option the
 725                                 bounding set is reset, and all prior
 726                                 settings have no
 727                                 effect.</para></listitem>
 728                         </varlistentry>
 729
 730                         <varlistentry>
 731                                 <term><varname>SecureBits=</varname></term>
 732                                 <listitem><para>Controls the secure
 733                                 bits set for the executed process. See
 734                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 735                                 for details. Takes a list of strings:
 736                                 <option>keep-caps</option>,
 737                                 <option>keep-caps-locked</option>,
 738                                 <option>no-setuid-fixup</option>,
 739                                 <option>no-setuid-fixup-locked</option>,
 740                                 <option>noroot</option> and/or
 741                                 <option>noroot-locked</option>. This
 742                                 option may appear more than once in
 743                                 which case the secure bits are
 744                                 ORed. If the empty string is assigned
 745                                 to this option the bits are reset to
 746                                 0.</para></listitem>
 747                         </varlistentry>
 748
 749                         <varlistentry>
 750                                 <term><varname>Capabilities=</varname></term>
 751                                 <listitem><para>Controls the
 752                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 753                                 set for the executed process. Take a
 754                                 capability string describing the
 755                                 effective, permitted and inherited
 756                                 capability sets as documented in
 757                                 <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 758                                 Note that these capability sets are
 759                                 usually influenced by the capabilities
 760                                 attached to the executed file. Due to
 761                                 that
 762                                 <varname>CapabilityBoundingSet=</varname>
 763                                 is probably the much more useful
 764                                 setting.</para></listitem>
 765                         </varlistentry>
 766
 767                         <varlistentry>
 768                                 <term><varname>ControlGroup=</varname></term>
 769
 770                                 <listitem><para>Controls the control
 771                                 groups the executed processes shall be
 772                                 made members of. Takes a
 773                                 space-separated list of cgroup
 774                                 identifiers. A cgroup identifier is
 775                                 formatted like
 776                                 <filename>cpu:/foo/bar</filename>,
 777                                 where "cpu" indicates the kernel
 778                                 control group controller used, and
 779                                 <filename>/foo/bar</filename> is the
 780                                 control group path. The controller
 781                                 name and ":" may be omitted in which
 782                                 case the named systemd control group
 783                                 hierarchy is implied. Alternatively,
 784                                 the path and ":" may be omitted, in
 785                                 which case the default control group
 786                                 path for this unit is implied.</para>
 787
 788                                 <para>This option may be used to place
 789                                 executed processes in arbitrary groups
 790                                 in arbitrary hierarchies -- which may
 791                                 then be externally configured with
 792                                 additional execution limits. By
 793                                 default systemd will place all
 794                                 executed processes in separate
 795                                 per-unit control groups (named after
 796                                 the unit) in the systemd named
 797                                 hierarchy. This option is primarily
 798                                 intended to place executed processes
 799                                 in specific paths in specific kernel
 800                                 controller hierarchies. It is not
 801                                 recommended to manipulate the service
 802                                 control group path in the systemd
 803                                 named hierarchy. For details about
 804                                 control groups see <ulink
 805                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para>
 806
 807                                 <para>This option may appear more than
 808                                 once, in which case the list of
 809                                 control group assignments is
 810                                 merged. If the same hierarchy gets two
 811                                 different paths assigned only the
 812                                 later setting will take effect. If the
 813                                 empty string is assigned to this
 814                                 option the list of control group
 815                                 assignments is reset, all previous
 816                                 assignments will have no
 817                                 effect.</para>
 818
 819                                 <para>Note that the list of control
 820                                 group assignments of a unit is
 821                                 extended implicitly based on the
 822                                 settings of
 823                                 <varname>DefaultControllers=</varname>
 824                                 of
 825                                 <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 826                                 but a unit's
 827                                 <varname>ControlGroup=</varname>
 828                                 setting for a specific controller
 829                                 takes precedence.</para></listitem>
 830                         </varlistentry>
 831
 832                         <varlistentry>
 833                                 <term><varname>ControlGroupModify=</varname></term>
 834                                 <listitem><para>Takes a boolean
 835                                 argument. If true, the control groups
 836                                 created for this unit will be owned by
 837                                 the user specified with
 838                                 <varname>User=</varname> (and the
 839                                 appropriate group), and he/she can create
 840                                 subgroups as well as add processes to
 841                                 the group.</para></listitem>
 842                         </varlistentry>
 843
 844                         <varlistentry>
 845                                 <term><varname>ControlGroupPersistent=</varname></term>
 846                                 <listitem><para>Takes a boolean
 847                                 argument. If true, the control groups
 848                                 created for this unit will be marked
 849                                 to be persistent, i.e. systemd will
 850                                 not remove them when stopping the
 851                                 unit. The default is false, meaning
 852                                 that the control groups will be
 853                                 removed when the unit is stopped. For
 854                                 details about the semantics of this
 855                                 logic see <ulink
 856                                 url="http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups">PaxControlGroups</ulink>.</para></listitem>
 857                         </varlistentry>
 858
 859                         <varlistentry>
 860                                 <term><varname>ControlGroupAttribute=</varname></term>
 861
 862                                 <listitem><para>Set a specific control
 863                                 group attribute for executed
 864                                 processes, and (if needed) add the
 865                                 executed processes to a cgroup in the
 866                                 hierarchy of the controller the
 867                                 attribute belongs to. Takes two
 868                                 space-separated arguments: the
 869                                 attribute name (syntax is
 870                                 <literal>cpu.shares</literal> where
 871                                 <literal>cpu</literal> refers to a
 872                                 specific controller and
 873                                 <literal>shares</literal> to the
 874                                 attribute name), and the attribute
 875                                 value. Example:
 876                                 <literal>ControlGroupAttribute=cpu.shares
 877                                 512</literal>. If this option is used
 878                                 for an attribute that belongs to a
 879                                 kernel controller hierarchy the unit
 880                                 is not already configured to be added
 881                                 to (for example via the
 882                                 <literal>ControlGroup=</literal>
 883                                 option) then the unit will be added to
 884                                 the controller and the default unit
 885                                 cgroup path is implied. Thus, using
 886                                 <varname>ControlGroupAttribute=</varname>
 887                                 is in most cases sufficient to make
 888                                 use of control group enforcements,
 889                                 explicit
 890                                 <varname>ControlGroup=</varname> are
 891                                 only necessary in case the implied
 892                                 default control group path for a
 893                                 service is not desirable. For details
 894                                 about control group attributes see
 895                                 <ulink
 896                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>. This
 897                                 option may appear more than once, in
 898                                 order to set multiple control group
 899                                 attributes. If this option is used
 900                                 multiple times for the same cgroup
 901                                 attribute only the later setting takes
 902                                 effect. If the empty string is
 903                                 assigned to this option the list of
 904                                 attributes is reset, all previous
 905                                 cgroup attribute settings have no
 906                                 effect, including those done with
 907                                 <varname>CPUShares=</varname>,
 908                                 <varname>MemoryLimit=</varname>,
 909                                 <varname>MemorySoftLimit</varname>,
 910                                 <varname>DeviceAllow=</varname>,
 911                                 <varname>DeviceDeny=</varname>,
 912                                 <varname>BlockIOWeight=</varname>,
 913                                 <varname>BlockIOReadBandwidth=</varname>,
 914                                 <varname>BlockIOWriteBandwidth=</varname>.
 915                                 </para></listitem>
 916                         </varlistentry>
 917
 918                         <varlistentry>
 919                                 <term><varname>CPUShares=</varname></term>
 920
 921                                 <listitem><para>Assign the specified
 922                                 overall CPU time shares to the
 923                                 processes executed. Takes an integer
 924                                 value. This controls the
 925                                 <literal>cpu.shares</literal> control
 926                                 group attribute, which defaults to
 927                                 1024. For details about this control
 928                                 group attribute see <ulink
 929                                 url="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para></listitem>
 930                         </varlistentry>
 931
 932                         <varlistentry>
 933                                 <term><varname>MemoryLimit=</varname></term>
 934                                 <term><varname>MemorySoftLimit=</varname></term>
 935
 936                                 <listitem><para>Limit the overall memory usage
 937                                 of the executed processes to a certain
 938                                 size. Takes a memory size in bytes. If
 939                                 the value is suffixed with K, M, G or
 940                                 T the specified memory size is parsed
 941                                 as Kilobytes, Megabytes, Gigabytes,
 942                                 or Terabytes (to the base
 943                                 1024), respectively. This controls the
 944                                 <literal>memory.limit_in_bytes</literal>
 945                                 and
 946                                 <literal>memory.soft_limit_in_bytes</literal>
 947                                 control group attributes. For details
 948                                 about these control group attributes
 949                                 see <ulink
 950                                 url="http://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para></listitem>
 951                         </varlistentry>
 952
 953                         <varlistentry>
 954                                 <term><varname>DeviceAllow=</varname></term>
 955                                 <term><varname>DeviceDeny=</varname></term>
 956
 957                                 <listitem><para>Control access to
 958                                 specific device nodes by the executed processes. Takes two
 959                                 space separated strings: a device node
 960                                 path (such as
 961                                 <filename>/dev/null</filename>)
 962                                 followed by a combination of r, w, m
 963                                 to control reading, writing, or
 964                                 creating of the specific device node
 965                                 by the unit, respectively. This controls the
 966                                 <literal>devices.allow</literal>
 967                                 and
 968                                 <literal>devices.deny</literal>
 969                                 control group attributes. For details
 970                                 about these control group attributes
 971                                 see <ulink
 972                                 url="http://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para></listitem>
 973                         </varlistentry>
 974
 975                         <varlistentry>
 976                                 <term><varname>BlockIOWeight=</varname></term>
 977
 978                                 <listitem><para>Set the default or
 979                                 per-device overall block IO weight
 980                                 value for the executed
 981                                 processes. Takes either a single
 982                                 weight value (between 10 and 1000) to
 983                                 set the default block IO weight, or a
 984                                 space separated pair of a file path
 985                                 and a weight value to specify the
 986                                 device specific weight value (Example:
 987                                 "/dev/sda 500"). The file path may be
 988                                 specified as path to a block device
 989                                 node or as any other file in which
 990                                 case the backing block device of the
 991                                 file system of the file is
 992                                 determined. This controls the
 993                                 <literal>blkio.weight</literal> and
 994                                 <literal>blkio.weight_device</literal>
 995                                 control group attributes, which
 996                                 default to 1000. Use this option
 997                                 multiple times to set weights for
 998                                 multiple devices. For details about
 999                                 these control group attributes see
1000                                 <ulink
1001                                 url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
1002                         </varlistentry>
1003
1004                         <varlistentry>
1005                                 <term><varname>BlockIOReadBandwidth=</varname></term>
1006                                 <term><varname>BlockIOWriteBandwidth=</varname></term>
1007
1008                                 <listitem><para>Set the per-device
1009                                 overall block IO bandwidth limit for
1010                                 the executed processes. Takes a space
1011                                 separated pair of a file path and a
1012                                 bandwidth value (in bytes per second)
1013                                 to specify the device specific
1014                                 bandwidth. The file path may be
1015                                 specified as path to a block device
1016                                 node or as any other file in which
1017                                 case the backing block device of the
1018                                 file system of the file is determined.
1019                                 If the bandwidth is suffixed with K, M,
1020                                 G, or T the specified bandwidth is
1021                                 parsed as Kilobytes, Megabytes,
1022                                 Gigabytes, or Terabytes, respectively (Example:
1023                                 "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
1024                                 5M"). This controls the
1025                                 <literal>blkio.read_bps_device</literal>
1026                                 and
1027                                 <literal>blkio.write_bps_device</literal>
1028                                 control group attributes. Use this
1029                                 option multiple times to set bandwidth
1030                                 limits for multiple devices. For
1031                                 details about these control group
1032                                 attributes see <ulink
1033                                 url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
1034                         </varlistentry>
1035
1036                         <varlistentry>
1037                                 <term><varname>ReadWriteDirectories=</varname></term>
1038                                 <term><varname>ReadOnlyDirectories=</varname></term>
1039                                 <term><varname>InaccessibleDirectories=</varname></term>
1040
1041                                 <listitem><para>Sets up a new
1042                                 file-system name space for executed
1043                                 processes. These options may be used
1044                                 to limit access a process might have
1045                                 to the main file-system
1046                                 hierarchy. Each setting takes a
1047                                 space-separated list of absolute
1048                                 directory paths. Directories listed in
1049                                 <varname>ReadWriteDirectories=</varname>
1050                                 are accessible from within the
1051                                 namespace with the same access rights
1052                                 as from outside. Directories listed in
1053                                 <varname>ReadOnlyDirectories=</varname>
1054                                 are accessible for reading only,
1055                                 writing will be refused even if the
1056                                 usual file access controls would
1057                                 permit this. Directories listed in
1058                                 <varname>InaccessibleDirectories=</varname>
1059                                 will be made inaccessible for
1060                                 processes inside the namespace. Note
1061                                 that restricting access with these
1062                                 options does not extend to submounts
1063                                 of a directory. You must list
1064                                 submounts separately in these settings
1065                                 to ensure the same limited
1066                                 access. These options may be specified
1067                                 more than once in which case all
1068                                 directories listed will have limited
1069                                 access from within the namespace. If
1070                                 the empty string is assigned to this
1071                                 option the specific list is reset, and
1072                                 all prior assignments have no
1073                                 effect.</para></listitem>
1074                         </varlistentry>
1075
1076                         <varlistentry>
1077                                 <term><varname>PrivateTmp=</varname></term>
1078
1079                                 <listitem><para>Takes a boolean
1080                                 argument. If true sets up a new file
1081                                 system namespace for the executed
1082                                 processes and mounts a private
1083                                 <filename>/tmp</filename> directory
1084                                 inside it, that is not shared by
1085                                 processes outside of the
1086                                 namespace. This is useful to secure
1087                                 access to temporary files of the
1088                                 process, but makes sharing between
1089                                 processes via
1090                                 <filename>/tmp</filename>
1091                                 impossible. Defaults to
1092                                 false.</para></listitem>
1093                         </varlistentry>
1094
1095                         <varlistentry>
1096                                 <term><varname>PrivateNetwork=</varname></term>
1097
1098                                 <listitem><para>Takes a boolean
1099                                 argument. If true sets up a new
1100                                 network namespace for the executed
1101                                 processes and configures only the
1102                                 loopback network device
1103                                 <literal>lo</literal> inside it. No
1104                                 other network devices will be
1105                                 available to the executed process.
1106                                 This is useful to securely turn off
1107                                 network access by the executed
1108                                 process. Defaults to
1109                                 false.</para></listitem>
1110                         </varlistentry>
1111
1112                         <varlistentry>
1113                                 <term><varname>MountFlags=</varname></term>
1114
1115                                 <listitem><para>Takes a mount
1116                                 propagation flag:
1117                                 <option>shared</option>,
1118                                 <option>slave</option> or
1119                                 <option>private</option>, which
1120                                 control whether the file system
1121                                 namespace set up for this unit's
1122                                 processes will receive or propagate
1123                                 new mounts. See
1124                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1125                                 for details. Default to
1126                                 <option>shared</option>.</para></listitem>
1127                         </varlistentry>
1128
1129                         <varlistentry>
1130                                 <term><varname>UtmpIdentifier=</varname></term>
1131
1132                                 <listitem><para>Takes a four
1133                                 character identifier string for an
1134                                 utmp/wtmp entry for this service. This
1135                                 should only be set for services such
1136                                 as <command>getty</command>
1137                                 implementations where utmp/wtmp
1138                                 entries must be created and cleared
1139                                 before and after execution. If the
1140                                 configured string is longer than four
1141                                 characters it is truncated and the
1142                                 terminal four characters are
1143                                 used. This setting interprets %I style
1144                                 string replacements. This setting is
1145                                 unset by default, i.e. no utmp/wtmp
1146                                 entries are created or cleaned up for
1147                                 this service.</para></listitem>
1148                         </varlistentry>
1149
1150                         <varlistentry>
1151                                 <term><varname>IgnoreSIGPIPE=</varname></term>
1152
1153                                 <listitem><para>Takes a boolean
1154                                 argument. If true causes SIGPIPE to be
1155                                 ignored in the executed
1156                                 process. Defaults to true, since
1157                                 SIGPIPE generally is useful only in
1158                                 shell pipelines.</para></listitem>
1159                         </varlistentry>
1160
1161                         <varlistentry>
1162                                 <term><varname>NoNewPrivileges=</varname></term>
1163
1164                                 <listitem><para>Takes a boolean
1165                                 argument. If true ensures that the
1166                                 service process and all its children
1167                                 can never gain new privileges. This
1168                                 option is more powerful than the respective
1169                                 secure bits flags (see above), as it
1170                                 also prohibits UID changes of any
1171                                 kind. This is the simplest, most
1172                                 effective way to ensure that a process
1173                                 and its children can never elevate
1174                                 privileges again.</para></listitem>
1175                         </varlistentry>
1176
1177                         <varlistentry>
1178                                 <term><varname>SystemCallFilter=</varname></term>
1179
1180                                 <listitem><para>Takes a space
1181                                 separated list of system call
1182                                 names. If this setting is used all
1183                                 system calls executed by the unit
1184                                 process except for the listed ones
1185                                 will result in immediate process
1186                                 termination with the SIGSYS signal
1187                                 (whitelisting). If the first character
1188                                 of the list is <literal>~</literal>
1189                                 the effect is inverted: only the
1190                                 listed system calls will result in
1191                                 immediate process termination
1192                                 (blacklisting). If this option is used
1193                                 <varname>NoNewPrivileges=yes</varname>
1194                                 is implied. This feature makes use of
1195                                 the Secure Computing Mode 2 interfaces
1196                                 of the kernel ('seccomp filtering')
1197                                 and is useful for enforcing a minimal
1198                                 sandboxing environment. Note that the
1199                                 <function>execve</function>,
1200                                 <function>rt_sigreturn</function>,
1201                                 <function>sigreturn</function>,
1202                                 <function>exit_group</function>,
1203                                 <function>exit</function> system calls
1204                                 are implicitly whitelisted and don't
1205                                 need to be listed explicitly. This
1206                                 option may be specified more than once
1207                                 in which case the filter masks are
1208                                 merged. If the empty string is
1209                                 assigned the filter is reset, all
1210                                 prior assignments will have no
1211                                 effect.</para></listitem>
1212                         </varlistentry>
1213
1214                 </variablelist>
1215         </refsect1>
1216
1217         <refsect1>
1218                   <title>See Also</title>
1219                   <para>
1220                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1221                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1222                           <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1223                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1224                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1225                           <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1226                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1227                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1228                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1229                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1230                   </para>
1231         </refsect1>
1232
1233 </refentry>