1JOURNALD.CONF(5)                 journald.conf                JOURNALD.CONF(5)


6       journald.conf, journald.conf.d - Journal service configuration files


9       /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


18       These files configure various parameters of the systemd journal
19       service, systemd-journald.service(8).


22       Default configuration is defined during compilation, so a configuration
23       file is only needed when it is necessary to deviate from those
24       defaults. By default the configuration file in /etc/systemd/ contains
25       commented out entries showing the defaults as a guide to the
26       administrator. This file can be edited to create local overrides.
28       When packages need to customize the configuration, they can install
29       configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
30       are reserved for the local administrator, who may use this logic to
31       override the configuration files installed by vendor packages. The main
32       configuration file is read before any of the configuration directories,
33       and has the lowest precedence; entries in a file in any configuration
34       directory override entries in the single configuration file. Files in
35       the *.conf.d/ configuration subdirectories are sorted by their filename
36       in lexicographic order, regardless of which of the subdirectories they
37       reside in. If multiple files specify the same option, the entry in the
38       file with the lexicographically latest name takes precedence. It is
39       recommended to prefix all filenames in those subdirectories with a
40       two-digit number and a dash, to simplify the ordering of the files.
42       To disable a configuration file supplied by the vendor, the recommended
43       way is to place a symlink to /dev/null in the configuration directory
44       in /etc/, with the same filename as the vendor configuration file.


47       All options are configured in the "[Journal]" section:
49       Storage=
50           Controls where to store journal data. One of "volatile",
51           "persistent", "auto" and "none". If "volatile", journal log data
52           will be stored only in memory, i.e. below the /run/log/journal
53           hierarchy (which is created if needed). If "persistent", data will
54           be stored preferably on disk, i.e. below the /var/log/journal
55           hierarchy (which is created if needed), with a fallback to
56           /run/log/journal (which is created if needed), during early boot
57           and if the disk is not writable.  "auto" is similar to "persistent"
58           but the directory /var/log/journal is not created if needed, so
59           that its existence controls where log data goes.  "none" turns off
60           all storage, all log data received will be dropped. Forwarding to
61           other targets, such as the console, the kernel log buffer, or a
62           syslog socket will still work however. Defaults to "auto".
64       Compress=
65           Takes a boolean value. If enabled (the default), data objects that
66           shall be stored in the journal and are larger than a certain
67           threshold are compressed before they are written to the file
68           system.
70       Seal=
71           Takes a boolean value. If enabled (the default), and a sealing key
72           is available (as created by journalctl(1)'s --setup-keys command),
73           Forward Secure Sealing (FSS) for all persistent journal files is
74           enabled. FSS is based on Seekable Sequential Key Generators[1] by
75           G. A. Marson and B. Poettering (doi:10.1007/978-3-642-40203-6_7)
76           and may be used to protect journal files from unnoticed alteration.
78       SplitMode=
79           Controls whether to split up journal files per user. One of "uid",
80           "login" and "none". If "uid", all users will get each their own
81           journal files regardless of whether they possess a login session or
82           not, however system users will log into the system journal. If
83           "login", actually logged-in users will get each their own journal
84           files, but users without login session and system users will log
85           into the system journal. If "none", journal files are not split up
86           by user and all messages are instead stored in the single system
87           journal. Note that splitting up journal files by user is only
88           available for journals stored persistently. If journals are stored
89           on volatile storage (see above), only a single journal file for all
90           user IDs is kept. Defaults to "uid".
92       RateLimitInterval=, RateLimitBurst=
93           Configures the rate limiting that is applied to all messages
94           generated on the system. If, in the time interval defined by
95           RateLimitInterval=, more messages than specified in RateLimitBurst=
96           are logged by a service, all further messages within the interval
97           are dropped until the interval is over. A message about the number
98           of dropped messages is generated. This rate limiting is applied
99           per-service, so that two services which log do not interfere with
100           each other's limits. Defaults to 1000 messages in 30s. The time
101           specification for RateLimitInterval= may be specified in the
102           following units: "s", "min", "h", "ms", "us". To turn off any kind
103           of rate limiting, set either value to 0.
105       SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, RuntimeMaxUse=,
106       RuntimeKeepFree=, RuntimeMaxFileSize=
107           Enforce size limits on the journal files stored. The options
108           prefixed with "System" apply to the journal files when stored on a
109           persistent file system, more specifically /var/log/journal. The
110           options prefixed with "Runtime" apply to the journal files when
111           stored on a volatile in-memory file system, more specifically
112           /run/log/journal. The former is used only when /var is mounted,
113           writable, and the directory /var/log/journal exists. Otherwise,
114           only the latter applies. Note that this means that during early
115           boot and if the administrator disabled persistent logging, only the
116           latter options apply, while the former apply if persistent logging
117           is enabled and the system is fully booted up.  journalctl and
118           systemd-journald ignore all files with names not ending with
119           ".journal" or ".journal~", so only such files, located in the
120           appropriate directories, are taken into account when calculating
121           current disk usage.
123           SystemMaxUse= and RuntimeMaxUse= control how much disk space the
124           journal may use up at maximum.  SystemKeepFree= and
125           RuntimeKeepFree= control how much disk space systemd-journald shall
126           leave free for other uses.  systemd-journald will respect both
127           limits and use the smaller of the two values.
129           The first pair defaults to 10% and the second to 15% of the size of
130           the respective file system, but each value is capped to 4G. If the
131           file system is nearly full and either SystemKeepFree= or
132           RuntimeKeepFree= is violated when systemd-journald is started, the
133           value will be raised to percentage that is actually free. This
134           means that if there was enough free space before and journal files
135           were created, and subsequently something else causes the file
136           system to fill up, journald will stop using more space, but it will
137           not be removing existing files to go reduce footprint either.
139           SystemMaxFileSize= and RuntimeMaxFileSize= control how large
140           individual journal files may grow at maximum. This influences the
141           granularity in which disk space is made available through rotation,
142           i.e. deletion of historic data. Defaults to one eighth of the
143           values configured with SystemMaxUse= and RuntimeMaxUse=, so that
144           usually seven rotated journal files are kept as history. Specify
145           values in bytes or use K, M, G, T, P, E as units for the specified
146           sizes (equal to 1024, 1024²,... bytes). Note that size limits are
147           enforced synchronously when journal files are extended, and no
148           explicit rotation step triggered by time is needed.
150       MaxFileSec=
151           The maximum time to store entries in a single journal file before
152           rotating to the next one. Normally, time-based rotation should not
153           be required as size-based rotation with options such as
154           SystemMaxFileSize= should be sufficient to ensure that journal
155           files do not grow without bounds. However, to ensure that not too
156           much data is lost at once when old journal files are deleted, it
157           might make sense to change this value from the default of one
158           month. Set to 0 to turn off this feature. This setting takes time
159           values which may be suffixed with the units "year", "month",
160           "week", "day", "h" or "m" to override the default time unit of
161           seconds.
163       MaxRetentionSec=
164           The maximum time to store journal entries. This controls whether
165           journal files containing entries older then the specified time span
166           are deleted. Normally, time-based deletion of old journal files
167           should not be required as size-based deletion with options such as
168           SystemMaxUse= should be sufficient to ensure that journal files do
169           not grow without bounds. However, to enforce data retention
170           policies, it might make sense to change this value from the default
171           of 0 (which turns off this feature). This setting also takes time
172           values which may be suffixed with the units "year", "month",
173           "week", "day", "h" or " m" to override the default time unit of
174           seconds.
176       SyncIntervalSec=
177           The timeout before synchronizing journal files to disk. After
178           syncing, journal files are placed in the OFFLINE state. Note that
179           syncing is unconditionally done immediately after a log message of
180           priority CRIT, ALERT or EMERG has been logged. This setting hence
181           applies only to messages of the levels ERR, WARNING, NOTICE, INFO,
182           DEBUG. The default timeout is 5 minutes.
184       ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=, ForwardToWall=
185           Control whether log messages received by the journal daemon shall
186           be forwarded to a traditional syslog daemon, to the kernel log
187           buffer (kmsg), to the system console, or sent as wall messages to
188           all logged-in users. These options take boolean arguments. If
189           forwarding to syslog is enabled but nothing reads messages from the
190           socket, forwarding to syslog has no effect. By default, only
191           forwarding to syslog and wall is enabled. These settings may be
192           overridden at boot time with the kernel command line options
193           "systemd.journald.forward_to_syslog=",
194           "systemd.journald.forward_to_kmsg=",
195           "systemd.journald.forward_to_console=", and
196           "systemd.journald.forward_to_wall=". When forwarding to the
197           console, the TTY to log to can be changed with TTYPath=, described
198           below.
200       MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
201       MaxLevelWall=
202           Controls the maximum log level of messages that are stored on disk,
203           forwarded to syslog, kmsg, the console or wall (if that is enabled,
204           see above). As argument, takes one of "emerg", "alert", "crit",
205           "err", "warning", "notice", "info", "debug", or integer values in
206           the range of 0..7 (corresponding to the same levels). Messages
207           equal or below the log level specified are stored/forwarded,
208           messages above are dropped. Defaults to "debug" for MaxLevelStore=
209           and MaxLevelSyslog=, to ensure that the all messages are written to
210           disk and forwarded to syslog. Defaults to "notice" for
211           MaxLevelKMsg=, "info" for MaxLevelConsole=, and "emerg" for
212           MaxLevelWall=.
214       TTYPath=
215           Change the console TTY to use if ForwardToConsole=yes is used.
216           Defaults to /dev/console.
218       LineMax=
219           The maximum line length to permit when converting stream logs into
220           record logs. When a systemd unit's standard output/error are
221           connected to the journal via a stream socket, the data read is
222           split into individual log records at newline ("\n", ASCII 10) and
223           NUL characters. If no such delimiter is read for the specified
224           number of bytes a hard log record boundary is artifically inserted,
225           breaking up overly long lines into multiple log records. Selecting
226           overly large values increases the possible memory usage of the
227           Journal daemon for each stream client, as in the worst case the
228           journal daemon needs to buffer the specified number of bytes in
229           memory before it can flush a new log record to disk. Also note that
230           permitting overly large line maximum line lengths affects
231           compatibility with traditional log protocols as log records might
232           not fit anymore into a single AF_UNIX or AF_INET datagram. Takes a
233           size in bytes. If the value is suffixed with K, M, G or T, the
234           specified size is parsed as Kilobytes, Megabytes, Gigabytes, or
235           Terabytes (with the base 1024), respectively. Defaults to 48K,
236           which is relatively large but still small enough so that log
237           records likely fit into network datagrams along with extra room for
238           metadata. Note that values below 79 are not accepted and will be
239           bumped to 79.


242       Journal events can be transferred to a different logging daemon in two
243       different ways. In the first method, messages are immediately forwarded
244       to a socket (/run/systemd/journal/syslog), where the traditional syslog
245       daemon can read them. This method is controlled by ForwardToSyslog=
246       option. In a second method, a syslog daemon behaves like a normal
247       journal client, and reads messages from the journal files, similarly to
248       journalctl(1). In this method, messages do not have to be read
249       immediately, which allows a logging daemon which is only started late
250       in boot to access all messages since the start of the system. In
251       addition, full structured meta-data is available to it. This method of
252       course is available only if the messages are stored in a journal file
253       at all. So it will not work if Storage=none is set. It should be noted
254       that usually the second method is used by syslog daemons, so the
255       Storage= option, and not the ForwardToSyslog= option, is relevant for
256       them.


259       systemd(1), systemd-journald.service(8), journalctl(1),
260       systemd.journal-fields(7), systemd-system.conf(5)


263        1. Seekable Sequential Key Generators
264           https://eprint.iacr.org/2013/397
268systemd 219                                                   JOURNALD.CONF(5)