1JOURNALD.CONF(5) journald.conf JOURNALD.CONF(5)
2
6 journald.conf, journald.conf.d, journald@.conf - Journal service
7 configuration files
8
10 /etc/systemd/journald.conf
11 /etc/systemd/journald.conf.d/*.conf
13 /run/systemd/journald.conf.d/*.conf
15 /usr/lib/systemd/journald.conf.d/*.conf
17 /etc/systemd/journald@NAMESPACE.conf
19 /etc/systemd/journald@NAMESPACE.conf.d/*.conf
21 /run/systemd/journald@NAMESPACE.conf.d/*.conf
23 /usr/lib/systemd/journald@NAMESPACE.conf.d/*.conf
25
27 These files configure various parameters of the systemd journal
28 service, systemd-journald.service(8). See systemd.syntax(7) for a
29 general description of the syntax.
30 The systemd-journald instance managing the default namespace is
32 configured by /etc/systemd/journald.conf and associated drop-ins.
33 Instances managing other namespaces read
34 /etc/systemd/journald@NAMESPACE.conf and associated drop-ins with the
35 namespace identifier filled in. This allows each namespace to carry a
36 distinct configuration. See systemd-journald.service(8) for details
37 about journal namespaces.
38
40 The default configuration is set during compilation, so configuration
41 is only needed when it is necessary to deviate from those defaults.
42 Initially, the main configuration file in /etc/systemd/ contains
43 commented out entries showing the defaults as a guide to the
44 administrator. Local overrides can be created by editing this file or
45 by creating drop-ins, as described below. Using drop-ins for local
46 configuration is recommended over modifications to the main
47 configuration file.
48 In addition to the "main" configuration file, drop-in configuration
50 snippets are read from /usr/lib/systemd/*.conf.d/,
51 /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/. Those
52 drop-ins have higher precedence and override the main configuration
53 file. Files in the *.conf.d/ configuration subdirectories are sorted by
54 their filename in lexicographic order, regardless of in which of the
55 subdirectories they reside. When multiple files specify the same
56 option, for options which accept just a single value, the entry in the
57 file sorted last takes precedence, and for options which accept a list
58 of values, entries are collected as they occur in the sorted files.
59 When packages need to customize the configuration, they can install
61 drop-ins under /usr/. Files in /etc/ are reserved for the local
62 administrator, who may use this logic to override the configuration
63 files installed by vendor packages. Drop-ins have to be used to
64 override package drop-ins, since the main configuration file has lower
65 precedence. It is recommended to prefix all filenames in those
66 subdirectories with a two-digit number and a dash, to simplify the
67 ordering of the files.
68 To disable a configuration file supplied by the vendor, the recommended
70 way is to place a symlink to /dev/null in the configuration directory
71 in /etc/, with the same filename as the vendor configuration file.
72
74 All options are configured in the [Journal] section:
75 Storage=
77 Controls where to store journal data. One of "volatile",
78 "persistent", "auto" and "none". If "volatile", journal log data
79 will be stored only in memory, i.e. below the /run/log/journal
80 hierarchy (which is created if needed). If "persistent", data will
81 be stored preferably on disk, i.e. below the /var/log/journal
82 hierarchy (which is created if needed), with a fallback to
83 /run/log/journal (which is created if needed), during early boot
84 and if the disk is not writable. "auto" behaves like "persistent"
85 if the /var/log/journal directory exists, and "volatile" otherwise
86 (the existence of the directory controls the storage mode). "none"
87 turns off all storage, all log data received will be dropped (but
88 forwarding to other targets, such as the console, the kernel log
89 buffer, or a syslog socket will still work). Defaults to "auto" in
90 the default journal namespace, and "persistent" in all others.
91 Note that journald will initially use volatile storage, until a
93 call to journalctl --flush (or sending SIGUSR1 to journald) will
94 cause it to switch to persistent logging (under the conditions
95 mentioned above). This is done automatically on boot via
96 "systemd-journal-flush.service".
97 Note that when this option is changed to "volatile", existing
99 persistent data is not removed. In the other direction,
100 journalctl(1) with the --flush option may be used to move volatile
101 data to persistent storage.
102 Compress=
104 Can take a boolean value. If enabled (the default), data objects
105 that shall be stored in the journal and are larger than the default
106 threshold of 512 bytes are compressed before they are written to
107 the file system. It can also be set to a number of bytes to specify
108 the compression threshold directly. Suffixes like K, M, and G can
109 be used to specify larger units.
110 Seal=
112 Takes a boolean value. If enabled (the default), and a sealing key
113 is available (as created by journalctl(1)'s --setup-keys command),
114 Forward Secure Sealing (FSS) for all persistent journal files is
115 enabled. FSS is based on Seekable Sequential Key Generators[1] by
116 G. A. Marson and B. Poettering (doi:10.1007/978-3-642-40203-6_7)
117 and may be used to protect journal files from unnoticed alteration.
118 SplitMode=
120 Controls whether to split up journal files per user, either "uid"
121 or "none". Split journal files are primarily useful for access
122 control: on UNIX/Linux access control is managed per file, and the
123 journal daemon will assign users read access to their journal
124 files. If "uid", all regular users (with UID outside the range of
125 system users, dynamic service users, and the nobody user) will each
126 get their own journal files, and system users will log to the
127 system journal. See Users, Groups, UIDs and GIDs on systemd
128 systems[2] for more details about UID ranges. If "none", journal
129 files are not split up by user and all messages are instead stored
130 in the single system journal. In this mode unprivileged users
131 generally do not have access to their own log data. Note that
132 splitting up journal files by user is only available for journals
133 stored persistently. If journals are stored on volatile storage
134 (see Storage= above), only a single journal file is used. Defaults
135 to "uid".
136 RateLimitIntervalSec=, RateLimitBurst=
138 Configures the rate limiting that is applied to all messages
139 generated on the system. If, in the time interval defined by
140 RateLimitIntervalSec=, more messages than specified in
141 RateLimitBurst= are logged by a service, all further messages
142 within the interval are dropped until the interval is over. A
143 message about the number of dropped messages is generated. This
144 rate limiting is applied per-service, so that two services which
145 log do not interfere with each other's limits. Defaults to 10000
146 messages in 30s. The time specification for RateLimitIntervalSec=
147 may be specified in the following units: "s", "min", "h", "ms",
148 "us". To turn off any kind of rate limiting, set either value to 0.
149 Note that the effective rate limit is multiplied by a factor
151 derived from the available free disk space for the journal.
152 Currently, this factor is calculated using the base 2 logarithm.
153 Table 1. Example RateLimitBurst= rate modifications by the
155 available disk space
156 ┌─────────────────────┬──────────────────┐
157 │Available Disk Space │ Burst Multiplier │
158 ├─────────────────────┼──────────────────┤
159 │<= 1MB │ 1 │
160 ├─────────────────────┼──────────────────┤
161 │<= 16MB │ 2 │
162 ├─────────────────────┼──────────────────┤
163 │<= 256MB │ 3 │
164 ├─────────────────────┼──────────────────┤
165 │<= 4GB │ 4 │
166 ├─────────────────────┼──────────────────┤
167 │<= 64GB │ 5 │
168 ├─────────────────────┼──────────────────┤
169 │<= 1TB │ 6 │
170 └─────────────────────┴──────────────────┘
171 If a service provides rate limits for itself through
172 LogRateLimitIntervalSec= and/or LogRateLimitBurst= in
173 systemd.exec(5), those values will override the settings specified
174 here.
175 SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, SystemMaxFiles=,
177 RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFileSize=, RuntimeMaxFiles=
178 Enforce size limits on the journal files stored. The options
179 prefixed with "System" apply to the journal files when stored on a
180 persistent file system, more specifically /var/log/journal. The
181 options prefixed with "Runtime" apply to the journal files when
182 stored on a volatile in-memory file system, more specifically
183 /run/log/journal. The former is used only when /var/ is mounted,
184 writable, and the directory /var/log/journal exists. Otherwise,
185 only the latter applies. Note that this means that during early
186 boot and if the administrator disabled persistent logging, only the
187 latter options apply, while the former apply if persistent logging
188 is enabled and the system is fully booted up. journalctl and
189 systemd-journald ignore all files with names not ending with
190 ".journal" or ".journal~", so only such files, located in the
191 appropriate directories, are taken into account when calculating
192 current disk usage.
193 SystemMaxUse= and RuntimeMaxUse= control how much disk space the
195 journal may use up at most. SystemKeepFree= and RuntimeKeepFree=
196 control how much disk space systemd-journald shall leave free for
197 other uses. systemd-journald will respect both limits and use the
198 smaller of the two values.
199 The first pair defaults to 10% and the second to 15% of the size of
201 the respective file system, but each value is capped to 4G. If the
202 file system is nearly full and either SystemKeepFree= or
203 RuntimeKeepFree= are violated when systemd-journald is started, the
204 limit will be raised to the percentage that is actually free. This
205 means that if there was enough free space before and journal files
206 were created, and subsequently something else causes the file
207 system to fill up, journald will stop using more space, but it will
208 not be removing existing files to reduce the footprint again,
209 either. Also note that only archived files are deleted to reduce
210 the space occupied by journal files. This means that, in effect,
211 there might still be more space used than SystemMaxUse= or
212 RuntimeMaxUse= limit after a vacuuming operation is complete.
213 SystemMaxFileSize= and RuntimeMaxFileSize= control how large
215 individual journal files may grow at most. This influences the
216 granularity in which disk space is made available through rotation,
217 i.e. deletion of historic data. Defaults to one eighth of the
218 values configured with SystemMaxUse= and RuntimeMaxUse=, so that
219 usually seven rotated journal files are kept as history.
220 Specify values in bytes or use K, M, G, T, P, E as units for the
222 specified sizes (equal to 1024, 1024², ... bytes). Note that size
223 limits are enforced synchronously when journal files are extended,
224 and no explicit rotation step triggered by time is needed.
225 SystemMaxFiles= and RuntimeMaxFiles= control how many individual
227 journal files to keep at most. Note that only archived files are
228 deleted to reduce the number of files until this limit is reached;
229 active files will stay around. This means that, in effect, there
230 might still be more journal files around in total than this limit
231 after a vacuuming operation is complete. This setting defaults to
232 100.
233 MaxFileSec=
235 The maximum time to store entries in a single journal file before
236 rotating to the next one. Normally, time-based rotation should not
237 be required as size-based rotation with options such as
238 SystemMaxFileSize= should be sufficient to ensure that journal
239 files do not grow without bounds. However, to ensure that not too
240 much data is lost at once when old journal files are deleted, it
241 might make sense to change this value from the default of one
242 month. Set to 0 to turn off this feature. This setting takes time
243 values which may be suffixed with the units "year", "month",
244 "week", "day", "h" or "m" to override the default time unit of
245 seconds.
246 MaxRetentionSec=
248 The maximum time to store journal entries. This controls whether
249 journal files containing entries older than the specified time span
250 are deleted. Normally, time-based deletion of old journal files
251 should not be required as size-based deletion with options such as
252 SystemMaxUse= should be sufficient to ensure that journal files do
253 not grow without bounds. However, to enforce data retention
254 policies, it might make sense to change this value from the default
255 of 0 (which turns off this feature). This setting also takes time
256 values which may be suffixed with the units "year", "month",
257 "week", "day", "h" or " m" to override the default time unit of
258 seconds.
259 SyncIntervalSec=
261 The timeout before synchronizing journal files to disk. After
262 syncing, journal files are placed in the OFFLINE state. Note that
263 syncing is unconditionally done immediately after a log message of
264 priority CRIT, ALERT or EMERG has been logged. This setting hence
265 applies only to messages of the levels ERR, WARNING, NOTICE, INFO,
266 DEBUG. The default timeout is 5 minutes.
267 ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=, ForwardToWall=
269 Control whether log messages received by the journal daemon shall
270 be forwarded to a traditional syslog daemon, to the kernel log
271 buffer (kmsg), to the system console, or sent as wall messages to
272 all logged-in users. These options take boolean arguments. If
273 forwarding to syslog is enabled but nothing reads messages from the
274 socket, forwarding to syslog has no effect. By default, only
275 forwarding to wall is enabled. These settings may be overridden at
276 boot time with the kernel command line options
277 "systemd.journald.forward_to_syslog",
278 "systemd.journald.forward_to_kmsg",
279 "systemd.journald.forward_to_console", and
280 "systemd.journald.forward_to_wall". If the option name is specified
281 without "=" and the following argument, true is assumed. Otherwise,
282 the argument is parsed as a boolean.
283 When forwarding to the console, the TTY to log to can be changed
285 with TTYPath=, described below.
286 When forwarding to the kernel log buffer (kmsg), make sure to
288 select a suitably large size for the log buffer, for example by
289 adding "log_buf_len=8M" to the kernel command line. systemd will
290 automatically disable kernel's rate-limiting applied to userspace
291 processes (equivalent to setting "printk.devkmsg=on").
292 MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
294 MaxLevelWall=
295 Controls the maximum log level of messages that are stored in the
296 journal, forwarded to syslog, kmsg, the console or wall (if that is
297 enabled, see above). As argument, takes one of "emerg", "alert",
298 "crit", "err", "warning", "notice", "info", "debug", or integer
299 values in the range of 0–7 (corresponding to the same levels).
300 Messages equal or below the log level specified are
301 stored/forwarded, messages above are dropped. Defaults to "debug"
302 for MaxLevelStore= and MaxLevelSyslog=, to ensure that the all
303 messages are stored in the journal and forwarded to syslog.
304 Defaults to "notice" for MaxLevelKMsg=, "info" for
305 MaxLevelConsole=, and "emerg" for MaxLevelWall=. These settings may
306 be overridden at boot time with the kernel command line options
307 "systemd.journald.max_level_store=",
308 "systemd.journald.max_level_syslog=",
309 "systemd.journald.max_level_kmsg=",
310 "systemd.journald.max_level_console=",
311 "systemd.journald.max_level_wall=".
312 ReadKMsg=
314 Takes a boolean value. If enabled systemd-journal processes
315 /dev/kmsg messages generated by the kernel. In the default journal
316 namespace this option is enabled by default, it is disabled in all
317 others.
318 Audit=
320 Takes a boolean value. If enabled systemd-journal will turn on
321 kernel auditing on start-up. If disabled it will turn it off. If
322 unset it will neither enable nor disable it, leaving the previous
323 state unchanged. Note that this option does not control whether
324 systemd-journald collects generated audit records, it just controls
325 whether it tells the kernel to generate them. This means if another
326 tool turns on auditing even if systemd-journald left it off, it
327 will still collect the generated messages. Defaults to on.
328 TTYPath=
330 Change the console TTY to use if ForwardToConsole=yes is used.
331 Defaults to /dev/console.
332 LineMax=
334 The maximum line length to permit when converting stream logs into
335 record logs. When a systemd unit's standard output/error are
336 connected to the journal via a stream socket, the data read is
337 split into individual log records at newline ("\n", ASCII 10) and
338 NUL characters. If no such delimiter is read for the specified
339 number of bytes a hard log record boundary is artificially
340 inserted, breaking up overly long lines into multiple log records.
341 Selecting overly large values increases the possible memory usage
342 of the Journal daemon for each stream client, as in the worst case
343 the journal daemon needs to buffer the specified number of bytes in
344 memory before it can flush a new log record to disk. Also note that
345 permitting overly large line maximum line lengths affects
346 compatibility with traditional log protocols as log records might
347 not fit anymore into a single AF_UNIX or AF_INET datagram. Takes a
348 size in bytes. If the value is suffixed with K, M, G or T, the
349 specified size is parsed as Kilobytes, Megabytes, Gigabytes, or
350 Terabytes (with the base 1024), respectively. Defaults to 48K,
351 which is relatively large but still small enough so that log
352 records likely fit into network datagrams along with extra room for
353 metadata. Note that values below 79 are not accepted and will be
354 bumped to 79.
355
357 Journal events can be transferred to a different logging daemon in two
358 different ways. With the first method, messages are immediately
359 forwarded to a socket (/run/systemd/journal/syslog), where the
360 traditional syslog daemon can read them. This method is controlled by
361 the ForwardToSyslog= option. With a second method, a syslog daemon
362 behaves like a normal journal client, and reads messages from the
363 journal files, similarly to journalctl(1). With this, messages do not
364 have to be read immediately, which allows a logging daemon which is
365 only started late in boot to access all messages since the start of the
366 system. In addition, full structured meta-data is available to it. This
367 method of course is available only if the messages are stored in a
368 journal file at all. So it will not work if Storage=none is set. It
369 should be noted that usually the second method is used by syslog
370 daemons, so the Storage= option, and not the ForwardToSyslog= option,
371 is relevant for them.
372
374 systemd(1), systemd-journald.service(8), journalctl(1),
375 systemd.journal-fields(7), systemd-system.conf(5)
376
378 1. Seekable Sequential Key Generators
379 https://eprint.iacr.org/2013/397
380 2. Users, Groups, UIDs and GIDs on systemd systems
382 https://systemd.io/UIDS-GIDS
383systemd 250 JOURNALD.CONF(5)