summaryrefslogtreecommitdiff
path: root/man/file-hierarchy.xml
blob: fb72693c0535d22e27b141e949f93c9773582eb8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!--
  This file is part of systemd.

  Copyright 2014 Lennart Poettering

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

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

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

<refentry id="file-hierarchy">

        <refentryinfo>
                <title>file-hierarchy</title>
                <productname>systemd</productname>

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

        <refmeta>
                <refentrytitle>file-hierarchy</refentrytitle>
                <manvolnum>7</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>file-hierarchy</refname>
                <refpurpose>File system hierarchy overview</refpurpose>
        </refnamediv>

        <refsect1>
                <title>Description</title>

                <para>Operating systems using the
                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                system and service manager are organized based on a
                file system hierarchy inspired by UNIX, more
                specifically the hierarchy described in the <ulink
                url="http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html">File
                System Hierarchy</ulink> specification and
                <citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
                manual page describes a more minimal, modernized
                subset of these specifications that defines more
                strictly the suggestions and restrictions systemd
                makes on the file system hierarchy.</para>
        </refsect1>

        <refsect1>
                <title>General Structure</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>/</filename></term>
                                <listitem><para>The file system
                                root. Usually writable, but this is
                                not required. Possibly a temporary
                                file system (<literal>tmpfs</literal>). Not shared with
                                other hosts (unless read-only).
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/boot</filename></term>
                                <listitem><para>The boot partition
                                used for bringing up the system. On
                                EFI systems this is possibly the EFI
                                System Partition, also see
                                <citerefentry><refentrytitle>systemd-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This
                                directory is usually strictly local
                                to the host, and should be considered
                                read-only, except when a new kernel or
                                boot loader is installed. This
                                directory only exists on systems that
                                run on physical or emulated hardware
                                that requires boot
                                loaders.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/etc</filename></term>
                                <listitem><para>System-specific
                                configuration. This directory may or
                                may not be read-only. Frequently, this
                                directory is pre-populated with
                                vendor-supplied configuration files,
                                but applications should not make
                                assumptions about this directory
                                being fully populated or populated at
                                all, and should fall back to defaults
                                if configuration is missing.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/home</filename></term>
                                <listitem><para>The location for
                                normal user's home
                                directories. Possibly shared with
                                other systems, and never
                                read-only. This directory should only
                                be used for normal users, never for
                                system users. This directory and
                                possibly the directories contained
                                within it might only become available
                                or writable in late boot or even only
                                after user authentication. This directory
                                might be placed on limited-functionality
                                network file systems, hence
                                applications should not assume the
                                full set of file API is available on
                                this directory. Applications should
                                generally not reference this directory
                                directly, but via the per-user
                                <varname>$HOME</varname> environment
                                variable, or via the home directory
                                field of the user
                                database.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/root</filename></term>
                                <listitem><para>The home directory of
                                the root user. The root user's home
                                directory is located outside of
                                <filename>/home</filename> in order to
                                make sure the root user may log in
                                even without <filename>/home</filename>
                                being available and
                                mounted.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/srv</filename></term>
                                <listitem><para>The place to store
                                general server payload, managed by the
                                administrator. No restrictions are
                                made how this directory is organized
                                internally. Generally writable, and
                                possibly shared among systems. This
                                directory might become available or
                                writable only very late during
                                boot.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/tmp</filename></term>
                                <listitem><para>The place for small
                                temporary files. This directory is
                                usually mounted as
                                a <literal>tmpfs</literal> instance, and
                                should hence not be used for larger
                                files. (Use
                                <filename>/var/tmp</filename> for
                                larger files.) Since the directory is
                                accessible to other users of the
                                system it is essential that this
                                directory is only written to with the
                                <citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                                <citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                and related calls. This directory is
                                usually flushed at boot-up. Also,
                                files that are not accessed within a
                                certain time are usually automatically
                                deleted. If applications find the
                                environment variable
                                <varname>$TMPDIR</varname> set they
                                should prefer using the directory
                                specified in it over directly
                                referencing
                                <filename>/tmp</filename> (see <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry> for details).</para></listitem>
                        </varlistentry>

                </variablelist>
        </refsect1>

        <refsect1>
                <title>Runtime Data</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>/run</filename></term>
                                <listitem><para>A
                                <literal>tmpfs</literal> file system
                                for system packages to place runtime
                                data in. This directory is flushed on
                                boot, and generally writable for
                                privileged programs
                                only. Always writable.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/run/log</filename></term>
                                <listitem><para>Runtime system
                                logs. System components may place
                                private logs in this directory. Always
                                writable, even when
                                <filename>/var/log</filename> might
                                not be accessible
                                yet.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/run/user</filename></term>
                                <listitem><para>Contains per-user
                                runtime directories, each usually
                                individually mounted
                                <literal>tmpfs</literal>
                                instances. Always writable, flushed at
                                each reboot and when the user logs
                                out. User code should not reference
                                this directory directly, but via the
                                <varname>$XDG_RUNTIME_DIR</varname>
                                environment variable, as documented in
                                the <ulink
                                url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
                                Base Directory
                                Specification</ulink>.</para></listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Vendor-supplied Operating System Resources</title>

                <variablelist>

                        <varlistentry>
                                <term><filename>/usr</filename></term>
                                <listitem><para>Vendor-supplied
                                operating system resources. Usually
                                read-only, but this is not
                                required. Possibly shared between
                                multiple hosts. This directory should
                                not be modified by the administrator,
                                except when installing or removing
                                vendor-supplied
                                packages.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/bin</filename></term>
                                <listitem><para>Binaries for user
                                commands, that shall appear in the
                                <varname>$PATH</varname> search
                                path. It is recommended not to place
                                binaries in this directory that are
                                not useful for invocation from a shell
                                (such as daemon binaries); these
                                should be placed in a subdirectory of
                                <filename>/usr/lib</filename>
                                instead.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/include</filename></term>
                                <listitem><para>C and C++ API header
                                files of system
                                libraries.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/lib</filename></term>
                                <listitem><para>Static vendor data
                                that is compatible with all
                                architectures (though not necessarily
                                architecture-independent). Note that
                                this includes internal
                                executables or other binaries that are
                                not regularly invoked from a
                                shell. Such binaries may be for any
                                architecture supported by the
                                system. Do not place public libraries
                                in this directory, use
                                <varname>$libdir</varname> (see
                                below), instead.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>$libdir</varname></term>
                                <listitem><para>Location for placing
                                dynamic libraries in. The precise
                                location depends on the operating
                                system and the architecture, and is
                                sometimes
                                <filename>/usr/lib</filename>,
                                <filename>/use/lib64</filename> or
                                <filename>/usr/lib/</filename>
                                suffixed by an architecture
                                identifier. This directory should not
                                be used for package-specific data,
                                unless this data is
                                architecture-dependent, too. To query
                                <varname>$libdir</varname> for the
                                primary architecture of the system,
                                invoke
                                <programlisting># pkg-config --variable=libdir systemd</programlisting></para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/share</filename></term>
                                <listitem><para>Resources shared
                                between multiple packages, such as
                                documentation, man pages, time zone
                                information, fonts and other
                                resources. Usually, the precise
                                location and format of files stored
                                below this directory is subject to
                                specifications that ensure
                                interoperability.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/share/doc</filename></term>
                                <listitem><para>Documentation for the
                                operating system or system
                                packages.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/share/factory/etc</filename></term>
                                <listitem><para>Repository for
                                vendor-supplied default configuration
                                files. This directory should be
                                populated with pristine vendor versions
                                of all configuration files that may be
                                placed in
                                <filename>/etc</filename>. This is
                                useful to compare the local
                                configuration of a system with vendor
                                defaults and to populate the local
                                configuration with
                                defaults.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/usr/share/factory/var</filename></term>

                                <listitem><para>Similar to
                                <filename>/usr/share/factory/etc</filename>
                                but for vendor versions of files in
                                the variable, persistent data
                                directory
                                <filename>/var</filename>.</para></listitem>

                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Persistent Variable System Data</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>/var</filename></term>
                                <listitem><para>Persistent, variable
                                system data. Must be writable. This
                                directory might be pre-populated with
                                vendor-supplied data, but applications
                                should be able to reconstruct
                                necessary files and directories in
                                this subhierarchy should they be
                                missing, as the system might start up
                                without this directory being
                                populated. Persistency is recommended,
                                but optional, to support ephemeral
                                systems. This directory might become
                                available or writable only very late
                                during boot. Components that are
                                required to operate during early boot
                                hence shall not unconditionally rely
                                on this directory.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/cache</filename></term>
                                <listitem><para>Persistent system
                                cache data. System components may
                                place non-essential data in this
                                directory. Flushing this directory
                                should have no effect on operation of
                                programs, except for increased
                                runtimes necessary to rebuild these
                                caches.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/lib</filename></term>
                                <listitem><para>Persistent system
                                data. System components may
                                place private data in this
                                directory.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/log</filename></term>
                                <listitem><para>Persistent system
                                logs. System components may place
                                private logs in this directory, though
                                it is recommended to do most logging
                                via the
                                <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                and
                                <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                calls.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/spool</filename></term>
                                <listitem><para>Persistent system
                                spool data, such as printer or mail
                                queues.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/tmp</filename></term>
                                <listitem><para>The place for larger
                                and persistent temporary files. In
                                contrast to <filename>/tmp</filename>
                                this directory is usually mounted from
                                a persistent physical file system and
                                can thus accept larger files. (Use
                                <filename>/tmp</filename> for smaller
                                files.) This directory is generally
                                not flushed at boot-up, but time-based
                                cleanup of files that have not been
                                accessed for a certain time is
                                applied. The same security
                                restrictions as with
                                <filename>/tmp</filename> apply, and
                                hence only
                                <citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                                <citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                or similar calls should be used to
                                make use of this directory. If
                                applications find the environment
                                variable <varname>$TMPDIR</varname>
                                set they should prefer using the
                                directory specified in it over
                                directly referencing
                                <filename>/var/tmp</filename> (see <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry> for details).
                                </para></listitem>
                        </varlistentry>

                </variablelist>
        </refsect1>

        <refsect1>
                <title>Virtual Kernel and API File Systems</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>/dev</filename></term>
                                <listitem><para>The root directory for
                                device nodes. Usually this directory
                                is mounted as a
                                <literal>devtmpfs</literal> instance,
                                but might be of a different type in
                                sandboxed/containerized setups. This
                                directory is managed jointly by the
                                kernel and
                                <citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                                and should not be written to by other
                                components. A number of special
                                purpose virtual file systems might be
                                mounted below this
                                directory.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/dev/shm</filename></term>
                                <listitem><para>Place for POSIX shared
                                memory segments, as created via
                                <citerefentry><refentrytitle>shm_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
                                directory is flushed on boot, and is a
                                <literal>tmpfs</literal> file
                                system. Since all users have write
                                access to this directory, special care
                                should be taken to avoid name clashes
                                and vulnerabilities. For normal users,
                                shared memory segments in this
                                directory are usually deleted when the
                                user logs out. Usually it is a better
                                idea to use memory mapped files in
                                <filename>/run</filename> (for system
                                programs) or
                                <varname>$XDG_RUNTIME_DIR</varname>
                                (for user programs) instead of POSIX
                                shared memory segments, since those
                                directories are not world-writable and
                                hence not vulnerable to
                                security-sensitive name
                                clashes.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/proc</filename></term>
                                <listitem><para>A virtual kernel file
                                system exposing the process list and
                                other functionality. This file system
                                is mostly an API to interface with the
                                kernel and not a place where normal
                                files may be stored. For details, see
                                <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>. A
                                number of special purpose virtual file
                                systems might be mounted below this
                                directory.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/proc/sys</filename></term>
                                <listitem><para>A hierarchy below
                                <filename>/proc</filename> that
                                exposes a number of kernel
                                tunables. The primary way to configure
                                the settings in this API file tree is
                                via
                                <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                files. In sandboxed/containerized
                                setups this directory is generally
                                mounted read-only.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/sys</filename></term>
                                <listitem><para>A virtual kernel file
                                system exposing discovered devices and
                                other functionality. This file system
                                is mostly an API to interface with the
                                kernel and not a place where normal
                                files may be stored. In
                                sandboxed/containerized setups this
                                directory is generally mounted
                                read-only. A number of special purpose
                                virtual file systems might be mounted
                                below this
                                directory.</para></listitem>
                        </varlistentry>


                </variablelist>
        </refsect1>

        <refsect1>
                <title>Compatibility Symlinks</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>/bin</filename></term>
                                <term><filename>/sbin</filename></term>
                                <term><filename>/usr/sbin</filename></term>

                                <listitem><para>These compatibility
                                symlinks point to
                                <filename>/usr/bin</filename>,
                                ensuring that scripts and binaries
                                referencing these legacy paths
                                correctly find their binaries.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/lib</filename></term>

                                <listitem><para>This compatibility
                                symlink points to
                                <filename>/usr/lib</filename>,
                                ensuring that programs referencing
                                this legacy path correctly find
                                their resources.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/lib64</filename></term>

                                <listitem><para>On some architecture
                                ABIs this compatibility symlink points
                                to <varname>$libdir</varname>,
                                ensuring that binaries referencing
                                this legacy path correctly find their
                                dynamic loader. This symlink only
                                exists on architectures whose ABI
                                places the dynamic loader in this
                                path.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><filename>/var/run</filename></term>

                                <listitem><para>This compatibility
                                symlink points to
                                <filename>/run</filename>, ensuring
                                that programs referencing this legacy
                                path correctly find their runtime
                                data.</para></listitem>
                        </varlistentry>

                </variablelist>
        </refsect1>

        <refsect1>
                <title>System Packages</title>

                <para>Developers of system packages should follow
                strict rules when placing their own files in the file
                system. The following table lists recommended
                locations for specific types of files.</para>

                <table>
                  <title>System Package Data Location</title>
                  <tgroup cols='2' align='left' colsep='1' rowsep='1'>
                    <colspec colname="directory" />
                    <colspec colname="purpose" />
                    <thead>
                      <row>
                        <entry>Directory</entry>
                        <entry>Purpose</entry>
                      </row>
                    </thead>
                    <tbody>
                      <row>
                        <entry><filename>/usr/bin</filename></entry>
                        <entry>Package executables that shall appear in the <varname>$PATH</varname> executable search path, compiled for the primary architecture of the operating system. It is not recommended to place internal binaries or binaries that are not commonly invoked from the shell in this directory, such as daemon binaries. As this directory is shared with most other packages of the system special care should be taken to pick unique names for files placed here, that are unlikely to clash with other package's files.</entry>
                      </row>
                      <row>
                        <entry><filename>$libdir</filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/usr/lib/<replaceable>package</replaceable></filename></entry>
                        <entry>Private static vendor resources of the package, including private binaries and libraries, or any other kind of read-only vendor data.</entry>
                      </row>
                      <row>
                        <entry><filename>$libdir/<replaceable>package</replaceable></filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/usr/include/<replaceable>package</replaceable></filename></entry>
                        <entry>Public C/C++ APIs of public shared libraries of the package.</entry>
                      </row>
                      <row>
                        <entry><filename>/etc/<replaceable>package</replaceable></filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/run/<replaceable>package</replaceable></filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/run/log/<replaceable>package</replaceable></filename></entry>
                        <entry>Runtime log data for the package.</entry>
                      </row>
                      <row>
                        <entry><filename>/var/cache/<replaceable>package</replaceable></filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/var/lib/<replaceable>package</replaceable></filename></entry>
                        <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>
                      </row>
                      <row>
                        <entry><filename>/var/log/<replaceable>package</replaceable></filename></entry>
                        <entry>Persistent log data of the package.</entry>
                      </row>
                      <row>
                        <entry><filename>/var/spool/<replaceable>package</replaceable></filename></entry>
                        <entry>Persistent spool/queue data of the package.</entry>
                      </row>
                    </tbody>
                  </tgroup>
                </table>
        </refsect1>

        <refsect1>
                <title>See Also</title>
                <para>
                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>