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
21 These files configure various parameters of the systemd journal
22 service, systemd-journald.service(8). See systemd.syntax(7) for a
23 general description of the syntax.
24 The systemd-journald instance managing the default namespace is
26 configured by /etc/systemd/journald.conf and associated drop-ins.
27 Instances managing other namespaces read
28 /etc/systemd/journald@NAMESPACE.conf with the namespace identifier
29 filled in. This allows each namespace to carry a distinct
30 configuration. See systemd-journald.service(8) for details about
31 journal namespaces.
32
34 The default configuration is defined during compilation, so a
35 configuration file is only needed when it is necessary to deviate from
36 those defaults. By default, the configuration file in /etc/systemd/
37 contains commented out entries showing the defaults as a guide to the
38 administrator. This file can be edited to create local overrides.
39 When packages need to customize the configuration, they can install
41 configuration snippets in /usr/lib/systemd/*.conf.d/ or
42 /usr/local/lib/systemd/*.conf.d/. The main configuration file is read
43 before any of the configuration directories, and has the lowest
44 precedence; entries in a file in any configuration directory override
45 entries in the single configuration file. Files in the *.conf.d/
46 configuration subdirectories are sorted by their filename in
47 lexicographic order, regardless of in which of the subdirectories they
48 reside. When multiple files specify the same option, for options which
49 accept just a single value, the entry in the file with the
50 lexicographically latest name takes precedence. For options which
51 accept a list of values, entries are collected as they occur in files
52 sorted lexicographically.
53 Files in /etc/ are reserved for the local administrator, who may use
55 this logic to override the configuration files installed by vendor
56 packages. It is recommended to prefix all filenames in those
57 subdirectories with a two-digit number and a dash, to simplify the
58 ordering of the files.
59 To disable a configuration file supplied by the vendor, the recommended
61 way is to place a symlink to /dev/null in the configuration directory
62 in /etc/, with the same filename as the vendor configuration file.
63
65 All options are configured in the [Journal] section:
66 Storage=
68 Controls where to store journal data. One of "volatile",
69 "persistent", "auto" and "none". If "volatile", journal log data
70 will be stored only in memory, i.e. below the /run/log/journal
71 hierarchy (which is created if needed). If "persistent", data will
72 be stored preferably on disk, i.e. below the /var/log/journal
73 hierarchy (which is created if needed), with a fallback to
74 /run/log/journal (which is created if needed), during early boot
75 and if the disk is not writable. "auto" behaves like "persistent"
76 if the /var/log/journal directory exists, and "volatile" otherwise
77 (the existence of the directory controls the storage mode). "none"
78 turns off all storage, all log data received will be dropped (but
79 forwarding to other targets, such as the console, the kernel log
80 buffer, or a syslog socket will still work). Defaults to "auto" in
81 the default journal namespace, and "persistent" in all others.
82 Note that when this option is changed to "volatile", existing
84 persistent data is not removed. In the other direction,
85 journalctl(1) with the --flush option may be used to move volatile
86 data to persistent storage.
87 Compress=
89 Can take a boolean value. If enabled (the default), data objects
90 that shall be stored in the journal and are larger than the default
91 threshold of 512 bytes are compressed before they are written to
92 the file system. It can also be set to a number of bytes to specify
93 the compression threshold directly. Suffixes like K, M, and G can
94 be used to specify larger units.
95 Seal=
97 Takes a boolean value. If enabled (the default), and a sealing key
98 is available (as created by journalctl(1)'s --setup-keys command),
99 Forward Secure Sealing (FSS) for all persistent journal files is
100 enabled. FSS is based on Seekable Sequential Key Generators[1] by
101 G. A. Marson and B. Poettering (doi:10.1007/978-3-642-40203-6_7)
102 and may be used to protect journal files from unnoticed alteration.
103 SplitMode=
105 Controls whether to split up journal files per user, either "uid"
106 or "none". Split journal files are primarily useful for access
107 control: on UNIX/Linux access control is managed per file, and the
108 journal daemon will assign users read access to their journal
109 files. If "uid", all regular users (with UID outside the range of
110 system users, dynamic service users, and the nobody user) will each
111 get their own journal files, and system users will log to the
112 system journal. See Users, Groups, UIDs and GIDs on systemd
113 systems[2] for more details about UID ranges. If "none", journal
114 files are not split up by user and all messages are instead stored
115 in the single system journal. In this mode unprivileged users
116 generally do not have access to their own log data. Note that
117 splitting up journal files by user is only available for journals
118 stored persistently. If journals are stored on volatile storage
119 (see Storage= above), only a single journal file is used. Defaults
120 to "uid".
121 RateLimitIntervalSec=, RateLimitBurst=
123 Configures the rate limiting that is applied to all messages
124 generated on the system. If, in the time interval defined by
125 RateLimitIntervalSec=, more messages than specified in
126 RateLimitBurst= are logged by a service, all further messages
127 within the interval are dropped until the interval is over. A
128 message about the number of dropped messages is generated. This
129 rate limiting is applied per-service, so that two services which
130 log do not interfere with each other's limits. Defaults to 10000
131 messages in 30s. The time specification for RateLimitIntervalSec=
132 may be specified in the following units: "s", "min", "h", "ms",
133 "us". To turn off any kind of rate limiting, set either value to 0.
134 Note that the effective rate limit is multiplied by a factor
136 derived from the available free disk space for the journal.
137 Currently, this factor is calculated using the base 2 logarithm.
138 Table 1. Example RateLimitBurst= rate modifications by the
140 available disk space
141 ┌─────────────────────┬──────────────────┐
142 │Available Disk Space │ Burst Multiplier │
143 ├─────────────────────┼──────────────────┤
144 │<= 1MB │ 1 │
145 ├─────────────────────┼──────────────────┤
146 │<= 16MB │ 2 │
147 ├─────────────────────┼──────────────────┤
148 │<= 256MB │ 3 │
149 ├─────────────────────┼──────────────────┤
150 │<= 4GB │ 4 │
151 ├─────────────────────┼──────────────────┤
152 │<= 64GB │ 5 │
153 ├─────────────────────┼──────────────────┤
154 │<= 1TB │ 6 │
155 └─────────────────────┴──────────────────┘
156 If a service provides rate limits for itself through
157 LogRateLimitIntervalSec= and/or LogRateLimitBurst= in
158 systemd.exec(5), those values will override the settings specified
159 here.
160 SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, SystemMaxFiles=,
162 RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFileSize=, RuntimeMaxFiles=
163 Enforce size limits on the journal files stored. The options
164 prefixed with "System" apply to the journal files when stored on a
165 persistent file system, more specifically /var/log/journal. The
166 options prefixed with "Runtime" apply to the journal files when
167 stored on a volatile in-memory file system, more specifically
168 /run/log/journal. The former is used only when /var is mounted,
169 writable, and the directory /var/log/journal exists. Otherwise,
170 only the latter applies. Note that this means that during early
171 boot and if the administrator disabled persistent logging, only the
172 latter options apply, while the former apply if persistent logging
173 is enabled and the system is fully booted up. journalctl and
174 systemd-journald ignore all files with names not ending with
175 ".journal" or ".journal~", so only such files, located in the
176 appropriate directories, are taken into account when calculating
177 current disk usage.
178 SystemMaxUse= and RuntimeMaxUse= control how much disk space the
180 journal may use up at most. SystemKeepFree= and RuntimeKeepFree=
181 control how much disk space systemd-journald shall leave free for
182 other uses. systemd-journald will respect both limits and use the
183 smaller of the two values.
184 The first pair defaults to 10% and the second to 15% of the size of
186 the respective file system, but each value is capped to 4G. If the
187 file system is nearly full and either SystemKeepFree= or
188 RuntimeKeepFree= are violated when systemd-journald is started, the
189 limit will be raised to the percentage that is actually free. This
190 means that if there was enough free space before and journal files
191 were created, and subsequently something else causes the file
192 system to fill up, journald will stop using more space, but it will
193 not be removing existing files to reduce the footprint again,
194 either. Also note that only archived files are deleted to reduce
195 the space occupied by journal files. This means that, in effect,
196 there might still be more space used than SystemMaxUse= or
197 RuntimeMaxUse= limit after a vacuuming operation is complete.
198 SystemMaxFileSize= and RuntimeMaxFileSize= control how large
200 individual journal files may grow at most. This influences the
201 granularity in which disk space is made available through rotation,
202 i.e. deletion of historic data. Defaults to one eighth of the
203 values configured with SystemMaxUse= and RuntimeMaxUse=, so that
204 usually seven rotated journal files are kept as history.
205 Specify values in bytes or use K, M, G, T, P, E as units for the
207 specified sizes (equal to 1024, 1024², ... bytes). Note that size
208 limits are enforced synchronously when journal files are extended,
209 and no explicit rotation step triggered by time is needed.
210 SystemMaxFiles= and RuntimeMaxFiles= control how many individual
212 journal files to keep at most. Note that only archived files are
213 deleted to reduce the number of files until this limit is reached;
214 active files will stay around. This means that, in effect, there
215 might still be more journal files around in total than this limit
216 after a vacuuming operation is complete. This setting defaults to
217 100.
218 MaxFileSec=
220 The maximum time to store entries in a single journal file before
221 rotating to the next one. Normally, time-based rotation should not
222 be required as size-based rotation with options such as
223 SystemMaxFileSize= should be sufficient to ensure that journal
224 files do not grow without bounds. However, to ensure that not too
225 much data is lost at once when old journal files are deleted, it
226 might make sense to change this value from the default of one
227 month. Set to 0 to turn off this feature. This setting takes time
228 values which may be suffixed with the units "year", "month",
229 "week", "day", "h" or "m" to override the default time unit of
230 seconds.
231 MaxRetentionSec=
233 The maximum time to store journal entries. This controls whether
234 journal files containing entries older than the specified time span
235 are deleted. Normally, time-based deletion of old journal files
236 should not be required as size-based deletion with options such as
237 SystemMaxUse= should be sufficient to ensure that journal files do
238 not grow without bounds. However, to enforce data retention
239 policies, it might make sense to change this value from the default
240 of 0 (which turns off this feature). This setting also takes time
241 values which may be suffixed with the units "year", "month",
242 "week", "day", "h" or " m" to override the default time unit of
243 seconds.
244 SyncIntervalSec=
246 The timeout before synchronizing journal files to disk. After
247 syncing, journal files are placed in the OFFLINE state. Note that
248 syncing is unconditionally done immediately after a log message of
249 priority CRIT, ALERT or EMERG has been logged. This setting hence
250 applies only to messages of the levels ERR, WARNING, NOTICE, INFO,
251 DEBUG. The default timeout is 5 minutes.
252 ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=, ForwardToWall=
254 Control whether log messages received by the journal daemon shall
255 be forwarded to a traditional syslog daemon, to the kernel log
256 buffer (kmsg), to the system console, or sent as wall messages to
257 all logged-in users. These options take boolean arguments. If
258 forwarding to syslog is enabled but nothing reads messages from the
259 socket, forwarding to syslog has no effect. By default, only
260 forwarding to wall is enabled. These settings may be overridden at
261 boot time with the kernel command line options
262 "systemd.journald.forward_to_syslog",
263 "systemd.journald.forward_to_kmsg",
264 "systemd.journald.forward_to_console", and
265 "systemd.journald.forward_to_wall". If the option name is specified
266 without "=" and the following argument, true is assumed. Otherwise,
267 the argument is parsed as a boolean.
268 When forwarding to the console, the TTY to log to can be changed
270 with TTYPath=, described below.
271 When forwarding to the kernel log buffer (kmsg), make sure to
273 select a suitably large size for the log buffer, for example by
274 adding "log_buf_len=8M" to the kernel command line. systemd will
275 automatically disable kernel's rate-limiting applied to userspace
276 processes (equivalent to setting "printk.devkmsg=on").
277 MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
279 MaxLevelWall=
280 Controls the maximum log level of messages that are stored in the
281 journal, forwarded to syslog, kmsg, the console or wall (if that is
282 enabled, see above). As argument, takes one of "emerg", "alert",
283 "crit", "err", "warning", "notice", "info", "debug", or integer
284 values in the range of 0–7 (corresponding to the same levels).
285 Messages equal or below the log level specified are
286 stored/forwarded, messages above are dropped. Defaults to "debug"
287 for MaxLevelStore= and MaxLevelSyslog=, to ensure that the all
288 messages are stored in the journal and forwarded to syslog.
289 Defaults to "notice" for MaxLevelKMsg=, "info" for
290 MaxLevelConsole=, and "emerg" for MaxLevelWall=. These settings may
291 be overridden at boot time with the kernel command line options
292 "systemd.journald.max_level_store=",
293 "systemd.journald.max_level_syslog=",
294 "systemd.journald.max_level_kmsg=",
295 "systemd.journald.max_level_console=",
296 "systemd.journald.max_level_wall=".
297 ReadKMsg=
299 Takes a boolean value. If enabled systemd-journal processes
300 /dev/kmsg messages generated by the kernel. In the default journal
301 namespace this option is enabled by default, it is disabled in all
302 others.
303 Audit=
305 Takes a boolean value. If enabled systemd-journal will turn on
306 kernel auditing on start-up. If disabled it will turn it off. If
307 unset it will neither enable nor disable it, leaving the previous
308 state unchanged. Note that this option does not control whether
309 systemd-journald collects generated audit records, it just controls
310 whether it tells the kernel to generate them. This means if another
311 tool turns on auditing even if systemd-journald left it off, it
312 will still collect the generated messages. Defaults to on.
313 TTYPath=
315 Change the console TTY to use if ForwardToConsole=yes is used.
316 Defaults to /dev/console.
317 LineMax=
319 The maximum line length to permit when converting stream logs into
320 record logs. When a systemd unit's standard output/error are
321 connected to the journal via a stream socket, the data read is
322 split into individual log records at newline ("\n", ASCII 10) and
323 NUL characters. If no such delimiter is read for the specified
324 number of bytes a hard log record boundary is artificially
325 inserted, breaking up overly long lines into multiple log records.
326 Selecting overly large values increases the possible memory usage
327 of the Journal daemon for each stream client, as in the worst case
328 the journal daemon needs to buffer the specified number of bytes in
329 memory before it can flush a new log record to disk. Also note that
330 permitting overly large line maximum line lengths affects
331 compatibility with traditional log protocols as log records might
332 not fit anymore into a single AF_UNIX or AF_INET datagram. Takes a
333 size in bytes. If the value is suffixed with K, M, G or T, the
334 specified size is parsed as Kilobytes, Megabytes, Gigabytes, or
335 Terabytes (with the base 1024), respectively. Defaults to 48K,
336 which is relatively large but still small enough so that log
337 records likely fit into network datagrams along with extra room for
338 metadata. Note that values below 79 are not accepted and will be
339 bumped to 79.
340
342 Journal events can be transferred to a different logging daemon in two
343 different ways. With the first method, messages are immediately
344 forwarded to a socket (/run/systemd/journal/syslog), where the
345 traditional syslog daemon can read them. This method is controlled by
346 the ForwardToSyslog= option. With a second method, a syslog daemon
347 behaves like a normal journal client, and reads messages from the
348 journal files, similarly to journalctl(1). With this, messages do not
349 have to be read immediately, which allows a logging daemon which is
350 only started late in boot to access all messages since the start of the
351 system. In addition, full structured meta-data is available to it. This
352 method of course is available only if the messages are stored in a
353 journal file at all. So it will not work if Storage=none is set. It
354 should be noted that usually the second method is used by syslog
355 daemons, so the Storage= option, and not the ForwardToSyslog= option,
356 is relevant for them.
357
359 systemd(1), systemd-journald.service(8), journalctl(1),
360 systemd.journal-fields(7), systemd-system.conf(5)
361
363 1. Seekable Sequential Key Generators
364 https://eprint.iacr.org/2013/397
365 2. Users, Groups, UIDs and GIDs on systemd systems
367 https://systemd.io/UIDS-GIDS
368systemd 246 JOURNALD.CONF(5)