chiark / gitweb /
journal: add references to SSKG paper FSS is based on
[elogind.git] / man / journald.conf.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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9   Copyright 2010 Lennart Poettering
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24
25 <refentry id="journald.conf">
26         <refentryinfo>
27                 <title>journald.conf</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>journald.conf</refentrytitle>
42                 <manvolnum>5</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>journald.conf</refname>
47                 <refpurpose>Journal service configuration file</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <para><filename>/etc/systemd/journald.conf</filename></para>
52         </refsynopsisdiv>
53
54         <refsect1>
55                 <title>Description</title>
56
57                 <para>This files configures various parameters of the
58                 systemd journal service
59                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
60
61         </refsect1>
62
63         <refsect1>
64                 <title>Options</title>
65
66                 <para>All options are configured in the
67                 <literal>[Journal]</literal> section:</para>
68
69                 <variablelist>
70
71                         <varlistentry>
72                                 <term><varname>Storage=</varname></term>
73
74                                 <listitem><para>Controls where to
75                                 store journal data. One of
76                                 <literal>volatile</literal>,
77                                 <literal>persistent</literal>,
78                                 <literal>auto</literal> and
79                                 <literal>none</literal>. If
80                                 <literal>volatile</literal> journal
81                                 log data will be stored only in
82                                 memory, i.e. below the
83                                 <filename>/run/log/journal</filename>
84                                 hierarchy (which is created if
85                                 needed). If
86                                 <literal>persistent</literal> data will
87                                 be stored preferably on disk,
88                                 i.e. below the
89                                 <filename>/var/log/journal</filename>
90                                 hierarchy (which is created if
91                                 needed), with a fallback to
92                                 <filename>/run/log/journal</filename>
93                                 (which is created if needed), during
94                                 early boot and if the disk is not
95                                 writable. <literal>auto</literal> is
96                                 similar to
97                                 <literal>persistent</literal> but the
98                                 directory
99                                 <filename>/var/log/journal</filename>
100                                 is not created if needed, so that its
101                                 existence controls where log data
102                                 goes. <literal>none</literal> turns
103                                 off all storage, all log data received
104                                 will be dropped. Forwarding to other
105                                 targets, such as the console, the
106                                 kernel log buffer or a syslog daemon
107                                 will still work however.  Defaults to
108                                 <literal>auto</literal>.</para></listitem>
109                         </varlistentry>
110
111                         <varlistentry>
112                                 <term><varname>Compress=</varname></term>
113
114                                 <listitem><para>Takes a boolean
115                                 value. If enabled (the default) data
116                                 objects that shall be stored in the
117                                 journal and are larger than a certain
118                                 threshold are compressed with the XZ
119                                 compression algorithm before they are
120                                 written to the file
121                                 system.</para></listitem>
122                         </varlistentry>
123
124                         <varlistentry>
125                                 <term><varname>Seal=</varname></term>
126
127                                 <listitem><para>Takes a boolean
128                                 value. If enabled (the default) and a
129                                 sealing key is available (as created
130                                 by
131                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
132                                 <option>--setup-keys</option>
133                                 command), forward secure sealing (FSS)
134                                 for all persistent journal files is
135                                 enabled. FSS is based on <ulink
136                                 url="http://eprint.iacr.org/2013/397">Seekable
137                                 Sequential Key Generators</ulink> by
138                                 G. A. Marson and B. Poettering and
139                                 may be used to protect journal files
140                                 from unnoticed
141                                 alteration.</para></listitem>
142                         </varlistentry>
143
144                         <varlistentry>
145                                 <term><varname>SplitMode=</varname></term>
146
147                                 <listitem><para>Controls whether to
148                                 split up journal files per user. One
149                                 of <literal>login</literal>,
150                                 <literal>uid</literal> and
151                                 <literal>none</literal>. If
152                                 <literal>login</literal> each logged
153                                 in user will get his own journal
154                                 files, but systemd user IDs will log
155                                 into the system journal. If
156                                 <literal>uid</literal> any user ID
157                                 will get his own journal files
158                                 regardless whether it belongs to a
159                                 system service or refers to a real
160                                 logged in user. If
161                                 <literal>none</literal> journal files
162                                 are not split up per-user and all
163                                 messages are stored in the single
164                                 system journal. Note that splitting
165                                 up journal files per-user is only
166                                 available of journals are stored
167                                 persistently. If journals are stored
168                                 on volatile storage (see above) only a
169                                 single journal file for all user IDs
170                                 is kept. Defaults to
171                                 <literal>login</literal>.</para></listitem>
172                         </varlistentry>
173
174                         <varlistentry>
175                                 <term><varname>RateLimitInterval=</varname></term>
176                                 <term><varname>RateLimitBurst=</varname></term>
177
178                                 <listitem><para>Configures the rate
179                                 limiting that is applied to all
180                                 messages generated on the system. If
181                                 in the time interval defined by
182                                 <varname>RateLimitInterval=</varname>
183                                 more messages than specified in
184                                 <varname>RateLimitBurst=</varname> are
185                                 logged by a service all further
186                                 messages within the interval are
187                                 dropped, until the interval is over. A
188                                 message about the number of dropped
189                                 messages is generated. This rate
190                                 limiting is applied per-service, so
191                                 that two services which log do not
192                                 interfere with each other's
193                                 limits. Defaults to 200 messages in
194                                 10s. The time specification for
195                                 <varname>RateLimitInterval=</varname>
196                                 may be specified in the following
197                                 units: <literal>s</literal>,
198                                 <literal>min</literal>,
199                                 <literal>h</literal>,
200                                 <literal>ms</literal>,
201                                 <literal>us</literal>. To turn off any
202                                 kind of rate limiting, set either
203                                 value to 0.</para></listitem>
204                         </varlistentry>
205
206                         <varlistentry>
207                                 <term><varname>SystemMaxUse=</varname></term>
208                                 <term><varname>SystemKeepFree=</varname></term>
209                                 <term><varname>SystemMaxFileSize=</varname></term>
210                                 <term><varname>RuntimeMaxUse=</varname></term>
211                                 <term><varname>RuntimeKeepFree=</varname></term>
212                                 <term><varname>RuntimeMaxFileSize=</varname></term>
213
214                                 <listitem><para>Enforce size limits on
215                                 the journal files stored. The options
216                                 prefixed with
217                                 <literal>System</literal> apply to the
218                                 journal files when stored on a
219                                 persistent file system, more
220                                 specifically
221                                 <filename>/var/log/journal</filename>. The
222                                 options prefixed with
223                                 <literal>Runtime</literal> apply to
224                                 the journal files when stored on a
225                                 volatile in-memory file system, more
226                                 specifically
227                                 <filename>/run/log/journal</filename>. The
228                                 former is used only when
229                                 <filename>/var</filename> is mounted,
230                                 writable and the directory
231                                 <filename>/var/log/journal</filename>
232                                 exists. Otherwise only the latter
233                                 applies. Note that this means that
234                                 during early boot and if the
235                                 administrator disabled persistent
236                                 logging only the latter options apply,
237                                 while the former apply if persistent
238                                 logging is enabled and the system is
239                                 fully booted
240                                 up. <varname>SystemMaxUse=</varname>
241                                 and <varname>RuntimeMaxUse=</varname>
242                                 control how much disk space the
243                                 journal may use up at
244                                 maximum. Defaults to 10% of the size
245                                 of the respective file
246                                 system. <varname>SystemKeepFree=</varname>
247                                 and
248                                 <varname>RuntimeKeepFree=</varname>
249                                 control how much disk space the
250                                 journal shall always leave free for
251                                 other uses if less than the disk space
252                                 configured in
253                                 <varname>SystemMaxUse=</varname> and
254                                 <varname>RuntimeMaxUse=</varname> is
255                                 available. Defaults to 15% of the size
256                                 of the respective file
257                                 system. <varname>SystemMaxFileSize=</varname>
258                                 and
259                                 <varname>RuntimeMaxFileSize=</varname>
260                                 control how large individual journal
261                                 files may grow at maximum. This
262                                 influences the granularity in which
263                                 disk space is made available through
264                                 rotation, i.e. deletion of historic
265                                 data. Defaults to one eighth of the
266                                 values configured with
267                                 <varname>SystemMaxUse=</varname> and
268                                 <varname>RuntimeMaxUse=</varname>, so
269                                 that usually seven rotated journal
270                                 files are kept as history. Specify
271                                 values in bytes or use K, M, G, T, P,
272                                 E as units for the specified sizes
273                                 (equal to 1024, 1024²,... bytes).
274                                 Note that size limits are
275                                 enforced synchronously to journal
276                                 files as they are extended, and need
277                                 no explicit rotation step triggered by
278                                 time.</para></listitem>
279                         </varlistentry>
280
281                         <varlistentry>
282                                 <term><varname>MaxFileSec=</varname></term>
283
284                                 <listitem><para>The maximum time to
285                                 store entries in a single journal
286                                 file, before rotating to the next
287                                 one. Normally time-based rotation
288                                 should not be required as size-based
289                                 rotation with options such as
290                                 <varname>SystemMaxFileSize=</varname>
291                                 should be sufficient to ensure that
292                                 journal files don't grow without
293                                 bounds. However, to ensure that not
294                                 too much data is lost at once when old
295                                 journal files are deleted it might
296                                 make sense to change this value from
297                                 the default of one month. Set to 0 to
298                                 turn off this feature. This setting
299                                 takes time values which may be
300                                 suffixed with the units year, month,
301                                 week, day, h, m to override the
302                                 default time unit of
303                                 seconds.</para></listitem>
304                         </varlistentry>
305
306                         <varlistentry>
307                                 <term><varname>MaxRetentionSec=</varname></term>
308
309                                 <listitem><para>The maximum time to
310                                 store journal entries. This
311                                 controls whether journal files
312                                 containing entries older then the
313                                 specified time span are
314                                 deleted. Normally time-based deletion
315                                 of old journal files should not be
316                                 required as size-based deletion with
317                                 options such as
318                                 <varname>SystemMaxUse=</varname>
319                                 should be sufficient to ensure that
320                                 journal files don't grow without
321                                 bounds. However, to enforce data
322                                 retention policies it might make sense
323                                 to change this value from the
324                                 default of 0 (which turns off this
325                                 feature). This setting also takes
326                                 time values which may be suffixed with
327                                 the units year, month, week, day, h, m
328                                 to override the default time unit of
329                                 seconds. </para></listitem>
330                         </varlistentry>
331
332
333                         <varlistentry>
334                                 <term><varname>SyncIntervalSec=</varname></term>
335
336                                 <listitem><para>The timeout before syncing journal
337                                 data to disk. After syncing journal files have
338                                 OFFLINE state. Default timeout is 5 minutes.
339                                 </para></listitem>
340                         </varlistentry>
341
342                         <varlistentry>
343                                 <term><varname>ForwardToSyslog=</varname></term>
344                                 <term><varname>ForwardToKMsg=</varname></term>
345                                 <term><varname>ForwardToConsole=</varname></term>
346
347                                 <listitem><para>Control whether log
348                                 messages received by the journal
349                                 daemon shall be forwarded to a
350                                 traditional syslog daemon, to the
351                                 kernel log buffer (kmsg), or to the
352                                 system console. These options take
353                                 boolean arguments. If forwarding to
354                                 syslog is enabled but no syslog daemon
355                                 is running the respective option has
356                                 no effect. By default only forwarding
357                                 to syslog is enabled. These settings
358                                 may be overridden at boot time with
359                                 the kernel command line options
360                                 <literal>systemd.journald.forward_to_syslog=</literal>,
361                                 <literal>systemd.journald.forward_to_kmsg=</literal>
362                                 and
363                                 <literal>systemd.journald.forward_to_console=</literal>.
364                                 </para></listitem>
365                         </varlistentry>
366
367                         <varlistentry>
368                                 <term><varname>MaxLevelStore=</varname></term>
369                                 <term><varname>MaxLevelSyslog=</varname></term>
370                                 <term><varname>MaxLevelKMsg=</varname></term>
371                                 <term><varname>MaxLevelConsole=</varname></term>
372
373                                 <listitem><para>Controls the maximum
374                                 log level of messages that are stored
375                                 on disk, forwarded to syslog, kmsg or
376                                 the console (if that is enabled, see
377                                 above). As argument, takes one of
378                                 <literal>emerg</literal>,
379                                 <literal>alert</literal>,
380                                 <literal>crit</literal>,
381                                 <literal>err</literal>,
382                                 <literal>warning</literal>,
383                                 <literal>notice</literal>,
384                                 <literal>info</literal>,
385                                 <literal>debug</literal> or integer
386                                 values in the range of 0..7 (corresponding
387                                 to the same levels). Messages equal or below
388                                 the log level specified are
389                                 stored/forwarded, messages above are
390                                 dropped. Defaults to
391                                 <literal>debug</literal> for
392                                 <varname>MaxLevelStore=</varname> and
393                                 <varname>MaxLevelSyslog=</varname>, to
394                                 ensure that the all messages are
395                                 written to disk and forwarded to
396                                 syslog. Defaults to
397                                 <literal>notice</literal> for
398                                 <varname>MaxLevelKMsg=</varname> and
399                                 <literal>info</literal> for
400                                 <varname>MaxLevelConsole=</varname>.</para></listitem>
401                         </varlistentry>
402
403                         <varlistentry>
404                                 <term><varname>TTYPath=</varname></term>
405
406                                 <listitem><para>Change the console TTY
407                                 to use if
408                                 <varname>ForwardToConsole=yes</varname>
409                                 is used. Defaults to
410                                 <filename>/dev/console</filename>.</para></listitem>
411                         </varlistentry>
412
413                 </variablelist>
414
415         </refsect1>
416
417         <refsect1>
418                   <title>See Also</title>
419                   <para>
420                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
421                           <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
422                           <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
423                           <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
424                           <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
425                   </para>
426         </refsect1>
427
428 </refentry>