man/file-hierarchy.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   8   Copyright 2014 Lennart Poettering
   9
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  23
  24 <refentry id="file-hierarchy">
  25
  26         <refentryinfo>
  27                 <title>file-hierarchy</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>file-hierarchy</refentrytitle>
  42                 <manvolnum>7</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>file-hierarchy</refname>
  47                 <refpurpose>File system hierarchy overview</refpurpose>
  48         </refnamediv>
  49
  50         <refsect1>
  51                 <title>Description</title>
  52
  53                 <para>Operating systems using the
  54                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  55                 system and service manager are organized based on a
  56                 file system hierarchy inspired by UNIX, more
  57                 specifically the hierarchy described in the <ulink
  58                 url="http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html">File
  59                 System Hierarchy</ulink> specification and
  60                 <citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
  61                 manual page describes a more minimal, modernized
  62                 subset of these specifications that defines more
  63                 strictly the suggestions and restrictions systemd
  64                 makes on the file system hierarchy.</para>
  65         </refsect1>
  66
  67         <refsect1>
  68                 <title>General Structure</title>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><filename>/</filename></term>
  73                                 <listitem><para>The file system
  74                                 root. Usually writable, but this is
  75                                 not required. Possibly a temporary
  76                                 file system (<literal>tmpfs</literal>). Not shared with
  77                                 other hosts (unless read-only).
  78                                 </para></listitem>
  79                         </varlistentry>
  80
  81                         <varlistentry>
  82                                 <term><filename>/boot</filename></term>
  83                                 <listitem><para>The boot partition
  84                                 used for bringing up the system. On
  85                                 EFI systems this is possibly the EFI
  86                                 System Partition, also see
  87                                 <citerefentry><refentrytitle>systemd-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This
  88                                 directory is usually strictly local
  89                                 to the host, and should be considered
  90                                 read-only, except when a new kernel or
  91                                 boot loader is installed. This
  92                                 directory only exists on systems that
  93                                 run on physical or emulated hardware
  94                                 that requires boot
  95                                 loaders.</para></listitem>
  96                         </varlistentry>
  97
  98                         <varlistentry>
  99                                 <term><filename>/etc</filename></term>
 100                                 <listitem><para>System-specific
 101                                 configuration. This directory may or
 102                                 may not be read-only. Frequently, this
 103                                 directory is pre-populated with
 104                                 vendor-supplied configuration files,
 105                                 but applications should not make
 106                                 assumptions about this directory
 107                                 being fully populated or populated at
 108                                 all, and should fall back to defaults
 109                                 if configuration is missing.</para></listitem>
 110                         </varlistentry>
 111
 112                         <varlistentry>
 113                                 <term><filename>/home</filename></term>
 114                                 <listitem><para>The location for
 115                                 normal user's home
 116                                 directories. Possibly shared with
 117                                 other systems, and never
 118                                 read-only. This directory should only
 119                                 be used for normal users, never for
 120                                 system users. This directory and
 121                                 possibly the directories contained
 122                                 within it might only become available
 123                                 or writable in late boot or even only
 124                                 after user authentication. This directory
 125                                 might be placed on limited-functionality
 126                                 network file systems, hence
 127                                 applications should not assume the
 128                                 full set of file API is available on
 129                                 this directory. Applications should
 130                                 generally not reference this directory
 131                                 directly, but via the per-user
 132                                 <varname>$HOME</varname> environment
 133                                 variable, or via the home directory
 134                                 field of the user
 135                                 database.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><filename>/root</filename></term>
 140                                 <listitem><para>The home directory of
 141                                 the root user. The root user's home
 142                                 directory is located outside of
 143                                 <filename>/home</filename> in order to
 144                                 make sure the root user may log in
 145                                 even without <filename>/home</filename>
 146                                 being available and
 147                                 mounted.</para></listitem>
 148                         </varlistentry>
 149
 150                         <varlistentry>
 151                                 <term><filename>/srv</filename></term>
 152                                 <listitem><para>The place to store
 153                                 general server payload, managed by the
 154                                 administrator. No restrictions are
 155                                 made how this directory is organized
 156                                 internally. Generally writable, and
 157                                 possibly shared among systems. This
 158                                 directory might become available or
 159                                 writable only very late during
 160                                 boot.</para></listitem>
 161                         </varlistentry>
 162
 163                         <varlistentry>
 164                                 <term><filename>/tmp</filename></term>
 165                                 <listitem><para>The place for small
 166                                 temporary files. This directory is
 167                                 usually mounted as
 168                                 a <literal>tmpfs</literal> instance, and
 169                                 should hence not be used for larger
 170                                 files. (Use
 171                                 <filename>/var/tmp</filename> for
 172                                 larger files.) Since the directory is
 173                                 accessible to other users of the
 174                                 system it is essential that this
 175                                 directory is only written to with the
 176                                 <citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 177                                 <citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 178                                 and related calls. This directory is
 179                                 usually flushed at boot-up. Also,
 180                                 files that are not accessed within a
 181                                 certain time are usually automatically
 182                                 deleted. If applications find the
 183                                 environment variable
 184                                 <varname>$TMP</varname> set they
 185                                 should prefer using the directory
 186                                 specified in it over directly
 187                                 referencing
 188                                 <filename>/tmp</filename>.</para></listitem>
 189                         </varlistentry>
 190
 191                 </variablelist>
 192         </refsect1>
 193
 194         <refsect1>
 195                 <title>Runtime Data</title>
 196
 197                 <variablelist>
 198                         <varlistentry>
 199                                 <term><filename>/run</filename></term>
 200                                 <listitem><para>A
 201                                 <literal>tmpfs</literal> file system
 202                                 for system packages to place runtime
 203                                 data in. This directory is flushed on
 204                                 boot, and generally writable for
 205                                 privileged programs
 206                                 only. Always writable.</para></listitem>
 207                         </varlistentry>
 208
 209                         <varlistentry>
 210                                 <term><filename>/run/log</filename></term>
 211                                 <listitem><para>Runtime system
 212                                 logs. System components may place
 213                                 private logs in this directory. Always
 214                                 writable, even when
 215                                 <filename>/var/log</filename> might
 216                                 not be accessible
 217                                 yet.</para></listitem>
 218                         </varlistentry>
 219
 220                         <varlistentry>
 221                                 <term><filename>/run/user</filename></term>
 222                                 <listitem><para>Contains per-user
 223                                 runtime directories, each usually
 224                                 individually mounted
 225                                 <literal>tmpfs</literal>
 226                                 instances. Always writable, flushed at
 227                                 each reboot and when the user logs
 228                                 out. User code should not reference
 229                                 this directory directly, but via the
 230                                 <varname>$XDG_RUNTIME_DIR</varname>
 231                                 environment variable, as documented in
 232                                 the <ulink
 233                                 url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
 234                                 Base Directory
 235                                 Specification</ulink>.</para></listitem>
 236                         </varlistentry>
 237                 </variablelist>
 238         </refsect1>
 239
 240         <refsect1>
 241                 <title>Vendor-supplied Operating System Resources</title>
 242
 243                 <variablelist>
 244
 245                         <varlistentry>
 246                                 <term><filename>/usr</filename></term>
 247                                 <listitem><para>Vendor-supplied
 248                                 operating system resources. Usually
 249                                 read-only, but this is not
 250                                 required. Possibly shared between
 251                                 multiple hosts. This directory should
 252                                 not be modified by the administrator,
 253                                 except when installing or removing
 254                                 vendor-supplied
 255                                 packages.</para></listitem>
 256                         </varlistentry>
 257
 258                         <varlistentry>
 259                                 <term><filename>/usr/bin</filename></term>
 260                                 <listitem><para>Binaries for user
 261                                 commands, that shall appear in the
 262                                 <varname>$PATH</varname> search
 263                                 path. It is recommended not to place
 264                                 binaries in this directory that are
 265                                 not useful for invocation from a shell
 266                                 (such as daemon binaries); these
 267                                 should be placed in a subdirectory of
 268                                 <filename>/usr/lib</filename>
 269                                 instead.</para></listitem>
 270                         </varlistentry>
 271
 272                         <varlistentry>
 273                                 <term><filename>/usr/include</filename></term>
 274                                 <listitem><para>C and C++ API header
 275                                 files of system
 276                                 libraries.</para></listitem>
 277                         </varlistentry>
 278
 279                         <varlistentry>
 280                                 <term><filename>/usr/lib</filename></term>
 281                                 <listitem><para>Static vendor data
 282                                 that is compatible with all
 283                                 architectures (though not necessarily
 284                                 architecture-independent). Note that
 285                                 this includes internal
 286                                 executables or other binaries that are
 287                                 not regularly invoked from a
 288                                 shell. Such binaries may be for any
 289                                 architecture supported by the
 290                                 system. Do not place public libraries
 291                                 in this directory, use
 292                                 <varname>$libdir</varname> (see
 293                                 below), instead.</para></listitem>
 294                         </varlistentry>
 295
 296                         <varlistentry>
 297                                 <term><varname>$libdir</varname></term>
 298                                 <listitem><para>Location for placing
 299                                 dynamic libraries in. The precise
 300                                 location depends on the operating
 301                                 system and the architecture, and is
 302                                 sometimes
 303                                 <filename>/usr/lib</filename>,
 304                                 <filename>/use/lib64</filename> or
 305                                 <filename>/usr/lib/</filename>
 306                                 suffixed by an architecture
 307                                 identifier. This directory should not
 308                                 be used for package-specific data,
 309                                 unless this data is
 310                                 architecture-dependent, too. To query
 311                                 <varname>$libdir</varname> for the
 312                                 primary architecture of the system,
 313                                 invoke
 314                                 <programlisting># pkg-config --variable=libdir systemd</programlisting></para></listitem>
 315                         </varlistentry>
 316
 317                         <varlistentry>
 318                                 <term><filename>/usr/share</filename></term>
 319                                 <listitem><para>Resources shared
 320                                 between multiple packages, such as
 321                                 documentation, man pages, time zone
 322                                 information, fonts and other
 323                                 resources. Usually, the precise
 324                                 location and format of files stored
 325                                 below this directory is subject to
 326                                 specifications that ensure
 327                                 interoperability.</para></listitem>
 328                         </varlistentry>
 329
 330                         <varlistentry>
 331                                 <term><filename>/usr/share/doc</filename></term>
 332                                 <listitem><para>Documentation for the
 333                                 operating system or system
 334                                 packages.</para></listitem>
 335                         </varlistentry>
 336
 337                         <varlistentry>
 338                                 <term><filename>/usr/share/factory/etc</filename></term>
 339                                 <listitem><para>Repository for
 340                                 vendor-supplied default configuration
 341                                 files. This directory should be
 342                                 populated with pristine vendor versions
 343                                 of all configuration files that may be
 344                                 placed in
 345                                 <filename>/etc</filename>. This is
 346                                 useful to compare the local
 347                                 configuration of a system with vendor
 348                                 defaults and to populate the local
 349                                 configuration with
 350                                 defaults.</para></listitem>
 351                         </varlistentry>
 352
 353                         <varlistentry>
 354                                 <term><filename>/usr/share/factory/var</filename></term>
 355
 356                                 <listitem><para>Similar to
 357                                 <filename>/usr/share/factory/etc</filename>
 358                                 but for vendor versions of files in
 359                                 the variable, persistent data
 360                                 directory
 361                                 <filename>/var</filename>.</para></listitem>
 362
 363                         </varlistentry>
 364                 </variablelist>
 365         </refsect1>
 366
 367         <refsect1>
 368                 <title>Persistent Variable System Data</title>
 369
 370                 <variablelist>
 371                         <varlistentry>
 372                                 <term><filename>/var</filename></term>
 373                                 <listitem><para>Persistent, variable
 374                                 system data. Must be writable. This
 375                                 directory might be pre-populated with
 376                                 vendor-supplied data, but applications
 377                                 should be able to reconstruct
 378                                 necessary files and directories in
 379                                 this subhierarchy should they be
 380                                 missing, as the system might start up
 381                                 without this directory being
 382                                 populated. Persistency is recommended,
 383                                 but optional, to support ephemeral
 384                                 systems. This directory might become
 385                                 available or writable only very late
 386                                 during boot. Components that are
 387                                 required to operate during early boot
 388                                 hence shall not unconditionally rely
 389                                 on this directory.</para></listitem>
 390                         </varlistentry>
 391
 392                         <varlistentry>
 393                                 <term><filename>/var/cache</filename></term>
 394                                 <listitem><para>Persistent system
 395                                 cache data. System components may
 396                                 place non-essential data in this
 397                                 directory. Flushing this directory
 398                                 should have no effect on operation of
 399                                 programs, except for increased
 400                                 runtimes necessary to rebuild these
 401                                 caches.</para></listitem>
 402                         </varlistentry>
 403
 404                         <varlistentry>
 405                                 <term><filename>/var/lib</filename></term>
 406                                 <listitem><para>Persistent system
 407                                 data. System components may
 408                                 place private data in this
 409                                 directory.</para></listitem>
 410                         </varlistentry>
 411
 412                         <varlistentry>
 413                                 <term><filename>/var/log</filename></term>
 414                                 <listitem><para>Persistent system
 415                                 logs. System components may place
 416                                 private logs in this directory, though
 417                                 it is recommended to do most logging
 418                                 via the
 419                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 420                                 and
 421                                 <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 422                                 calls.</para></listitem>
 423                         </varlistentry>
 424
 425                         <varlistentry>
 426                                 <term><filename>/var/spool</filename></term>
 427                                 <listitem><para>Persistent system
 428                                 spool data, such as printer or mail
 429                                 queues.</para></listitem>
 430                         </varlistentry>
 431
 432                         <varlistentry>
 433                                 <term><filename>/var/tmp</filename></term>
 434                                 <listitem><para>The place for larger
 435                                 and persistent temporary files. In
 436                                 contrast to <filename>/tmp</filename>
 437                                 this directory is usually mounted from
 438                                 a persistent physical file system and
 439                                 can thus accept larger files. (Use
 440                                 <filename>/tmp</filename> for smaller
 441                                 files.) This directory is generally
 442                                 not flushed at boot-up, but time-based
 443                                 cleanup of files that have not been
 444                                 accessed for a certain time is
 445                                 applied. The same security
 446                                 restrictions as with
 447                                 <filename>/tmp</filename> apply, and
 448                                 hence only
 449                                 <citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 450                                 <citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 451                                 or similar calls should be used to
 452                                 make use of this directory. If
 453                                 applications find the environment
 454                                 variable <varname>$TMP</varname> set
 455                                 they should prefer using the directory
 456                                 specified in it over directly
 457                                 referencing
 458                                 <filename>/var/tmp</filename>.
 459                                 </para></listitem>
 460                         </varlistentry>
 461
 462                 </variablelist>
 463         </refsect1>
 464
 465         <refsect1>
 466                 <title>Virtual Kernel and API File Systems</title>
 467
 468                 <variablelist>
 469                         <varlistentry>
 470                                 <term><filename>/dev</filename></term>
 471                                 <listitem><para>The root directory for
 472                                 device nodes. Usually this directory
 473                                 is mounted as a
 474                                 <literal>devtmpfs</literal> instance,
 475                                 but might be of a different type in
 476                                 sandboxed/containerized setups. This
 477                                 directory is managed jointly by the
 478                                 kernel and
 479                                 <citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 480                                 and should not be written to by other
 481                                 components. A number of special
 482                                 purpose virtual file systems might be
 483                                 mounted below this
 484                                 directory.</para></listitem>
 485                         </varlistentry>
 486
 487                         <varlistentry>
 488                                 <term><filename>/dev/shm</filename></term>
 489                                 <listitem><para>Place for POSIX shared
 490                                 memory segments, as created via
 491                                 <citerefentry><refentrytitle>shm_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
 492                                 directory is flushed on boot, and is a
 493                                 <literal>tmpfs</literal> file
 494                                 system. Since all users have write
 495                                 access to this directory, special care
 496                                 should be taken to avoid name clashes
 497                                 and vulnerabilities. For normal users,
 498                                 shared memory segments in this
 499                                 directory are usually deleted when the
 500                                 user logs out. Usually it is a better
 501                                 idea to use memory mapped files in
 502                                 <filename>/run</filename> (for system
 503                                 programs) or
 504                                 <varname>$XDG_RUNTIME_DIR</varname>
 505                                 (for user programs) instead of POSIX
 506                                 shared memory segments, since those
 507                                 directories are not world-writable and
 508                                 hence not vulnerable to
 509                                 security-sensitive name
 510                                 clashes.</para></listitem>
 511                         </varlistentry>
 512
 513                         <varlistentry>
 514                                 <term><filename>/proc</filename></term>
 515                                 <listitem><para>A virtual kernel file
 516                                 system exposing the process list and
 517                                 other functionality. This file system
 518                                 is mostly an API to interface with the
 519                                 kernel and not a place where normal
 520                                 files may be stored. For details, see
 521                                 <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>. A
 522                                 number of special purpose virtual file
 523                                 systems might be mounted below this
 524                                 directory.</para></listitem>
 525                         </varlistentry>
 526
 527                         <varlistentry>
 528                                 <term><filename>/proc/sys</filename></term>
 529                                 <listitem><para>A hierarchy below
 530                                 <filename>/proc</filename> that
 531                                 exposes a number of kernel
 532                                 tunables. The primary way to configure
 533                                 the settings in this API file tree is
 534                                 via
 535                                 <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 536                                 files. In sandboxed/containerized
 537                                 setups this directory is generally
 538                                 mounted read-only.</para></listitem>
 539                         </varlistentry>
 540
 541                         <varlistentry>
 542                                 <term><filename>/sys</filename></term>
 543                                 <listitem><para>A virtual kernel file
 544                                 system exposing discovered devices and
 545                                 other functionality. This file system
 546                                 is mostly an API to interface with the
 547                                 kernel and not a place where normal
 548                                 files may be stored. In
 549                                 sandboxed/containerized setups this
 550                                 directory is generally mounted
 551                                 read-only. A number of special purpose
 552                                 virtual file systems might be mounted
 553                                 below this
 554                                 directory.</para></listitem>
 555                         </varlistentry>
 556
 557
 558                 </variablelist>
 559         </refsect1>
 560
 561         <refsect1>
 562                 <title>Compatibility Symlinks</title>
 563
 564                 <variablelist>
 565                         <varlistentry>
 566                                 <term><filename>/bin</filename></term>
 567                                 <term><filename>/sbin</filename></term>
 568                                 <term><filename>/usr/sbin</filename></term>
 569
 570                                 <listitem><para>These compatibility
 571                                 symlinks point to
 572                                 <filename>/usr/bin</filename>,
 573                                 ensuring that scripts and binaries
 574                                 referencing these legacy paths
 575                                 correctly find their binaries.</para></listitem>
 576                         </varlistentry>
 577
 578                         <varlistentry>
 579                                 <term><filename>/lib</filename></term>
 580
 581                                 <listitem><para>This compatibility
 582                                 symlink points to
 583                                 <filename>/usr/lib</filename>,
 584                                 ensuring that programs referencing
 585                                 this legacy path correctly find
 586                                 their resources.</para></listitem>
 587                         </varlistentry>
 588
 589                         <varlistentry>
 590                                 <term><filename>/lib64</filename></term>
 591
 592                                 <listitem><para>On some architecture
 593                                 ABIs this compatibility symlink points
 594                                 to <varname>$libdir</varname>,
 595                                 ensuring that binaries referencing
 596                                 this legacy path correctly find their
 597                                 dynamic loader. This symlink only
 598                                 exists on architectures whose ABI
 599                                 places the dynamic loader in this
 600                                 path.</para></listitem>
 601                         </varlistentry>
 602
 603                         <varlistentry>
 604                                 <term><filename>/var/run</filename></term>
 605
 606                                 <listitem><para>This compatibility
 607                                 symlink points to
 608                                 <filename>/run</filename>, ensuring
 609                                 that programs referencing this legacy
 610                                 path correctly find their runtime
 611                                 data.</para></listitem>
 612                         </varlistentry>
 613
 614                 </variablelist>
 615         </refsect1>
 616
 617         <refsect1>
 618                 <title>System Packages</title>
 619
 620                 <para>Developers of system packages should follow
 621                 strict rules when placing their own files in the file
 622                 system. The following table lists recommended
 623                 locations for specific types of files.</para>
 624
 625                 <table>
 626                   <title>System Package Data Location</title>
 627                   <tgroup cols='2' align='left' colsep='1' rowsep='1'>
 628                     <colspec colname="directory" />
 629                     <colspec colname="purpose" />
 630                     <thead>
 631                       <row>
 632                         <entry>Directory</entry>
 633                         <entry>Purpose</entry>
 634                       </row>
 635                     </thead>
 636                     <tbody>
 637                       <row>
 638                         <entry><filename>/usr/bin</filename></entry>
 639                         <entry>Package executables that shall appear in the <varname>$PATH</varname> executable search path, compiled for the primary architecture of the operating system. It is not recommended to place internal binaries or binaries that are not commonly invoked from the shell in this directory, such as daemon binaries. As this directory is shared with most other packages of the system special care should be taken to pick unique names for files placed here, that are unlikely to clash with other package's files.</entry>
 640                       </row>
 641                       <row>
 642                         <entry><filename>$libdir</filename></entry>
 643                         <entry>Public shared libraries of the package. As above, be careful with using too generic names, and pick unique names for your libraries to place here to avoid name clashes.</entry>
 644                       </row>
 645                       <row>
 646                         <entry><filename>/usr/lib/<replaceable>package</replaceable></filename></entry>
 647                         <entry>Private static vendor resources of the package, including private binaries and libraries, or any other kind of read-only vendor data.</entry>
 648                       </row>
 649                       <row>
 650                         <entry><filename>$libdir/<replaceable>package</replaceable></filename></entry>
 651                         <entry>Private other vendor resources of the package that are architecture-specific and cannot be shared between architectures. Note that this generally does not include private exectuables since binaries of a specific architecture may be freely invoked from any other supported system architecture.</entry>
 652                       </row>
 653                       <row>
 654                         <entry><filename>/usr/include/<replaceable>package</replaceable></filename></entry>
 655                         <entry>Public C/C++ APIs of public shared libraries of the package.</entry>
 656                       </row>
 657                       <row>
 658                         <entry><filename>/etc/<replaceable>package</replaceable></filename></entry>
 659                         <entry>System-specific configuration for the package. It is recommended to default to safe fallbacks if this configuration is missing, if this is possible. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to copy or symlink the necessary files and directories from <filename>/usr/share/factory</filename> during boot, via the <literal>L</literal> or <literal>C</literal> directives.</entry>
 660                       </row>
 661                       <row>
 662                         <entry><filename>/run/<replaceable>package</replaceable></filename></entry>
 663                         <entry>Runtime data for the package. Packages must be able to create the necessary subdirectories in this tree on their own, since the directory is flushed automatically on boot. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to create the necessary directories during boot.</entry>
 664                       </row>
 665                       <row>
 666                         <entry><filename>/run/log/<replaceable>package</replaceable></filename></entry>
 667                         <entry>Runtime log data for the package.</entry>
 668                       </row>
 669                       <row>
 670                         <entry><filename>/var/cache/<replaceable>package</replaceable></filename></entry>
 671                         <entry>Persistent cache data of the package. If this directory is flushed the application should work correctly on next invocation, though possibly slowed done due to the need to rebuild any local cache files.</entry>
 672                       </row>
 673                       <row>
 674                         <entry><filename>/var/lib/<replaceable>package</replaceable></filename></entry>
 675                         <entry>Persistent private data of the package. This is the primary place to put persistent data that does not fall into the other categories listed. Packages should be able to create the necessary subdirectories in this tree on their own, since the directory might be missing on boot. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to create the necessary directories during boot.</entry>
 676                       </row>
 677                       <row>
 678                         <entry><filename>/var/log/<replaceable>package</replaceable></filename></entry>
 679                         <entry>Persistent log data of the package.</entry>
 680                       </row>
 681                       <row>
 682                         <entry><filename>/var/spool/<replaceable>package</replaceable></filename></entry>
 683                         <entry>Persistent spool/queue data of the package.</entry>
 684                       </row>
 685                     </tbody>
 686                   </tgroup>
 687                 </table>
 688         </refsect1>
 689
 690         <refsect1>
 691                 <title>See Also</title>
 692                 <para>
 693                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 694                         <citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 695                         <citerefentry><refentrytitle>systemd-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 696                         <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 697                         <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 698                 </para>
 699         </refsect1>
 700
 701 </refentry>