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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | OPTIONS | FORWARDING TO TRADITIONAL SYSLOG DAEMONS | SEE ALSO | NOTES | COLOPHON |
JOURNALD.CONF(5) journald.conf JOURNALD.CONF(5)
journald.conf, journald.conf.d - Journal service configuration files
/etc/systemd/journald.conf
/etc/systemd/journald.conf.d/*.conf
/run/systemd/journald.conf.d/*.conf
/usr/lib/systemd/journald.conf.d/*.conf
These files configure various parameters of the systemd journal
service, systemd-journald.service(8).
The default configuration is defined during compilation, so a
configuration file is only needed when it is necessary to deviate
from those defaults. By default, the configuration file in
/etc/systemd/ contains commented out entries showing the defaults as
a guide to the administrator. This file can be edited to create local
overrides.
When packages need to customize the configuration, they can install
configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
are reserved for the local administrator, who may use this logic to
override the configuration files installed by vendor packages. The
main configuration file is read before any of the configuration
directories, and has the lowest precedence; entries in a file in any
configuration directory override entries in the single configuration
file. Files in the *.conf.d/ configuration subdirectories are sorted
by their filename in lexicographic order, regardless of which of the
subdirectories they reside in. If multiple files specify the same
option, the entry in the file with the lexicographically latest name
takes precedence. It is recommended to prefix all filenames in those
subdirectories with a two-digit number and a dash, to simplify the
ordering of the files.
To disable a configuration file supplied by the vendor, the
recommended way is to place a symlink to /dev/null in the
configuration directory in /etc/, with the same filename as the
vendor configuration file.
All options are configured in the "[Journal]" section:
Storage=
Controls where to store journal data. One of "volatile",
"persistent", "auto" and "none". If "volatile", journal log data
will be stored only in memory, i.e. below the /run/log/journal
hierarchy (which is created if needed). If "persistent", data
will be stored preferably on disk, i.e. below the
/var/log/journal hierarchy (which is created if needed), with a
fallback to /run/log/journal (which is created if needed), during
early boot and if the disk is not writable. "auto" is similar to
"persistent" but the directory /var/log/journal is not created if
needed, so that its existence controls where log data goes.
"none" turns off all storage, all log data received will be
dropped. Forwarding to other targets, such as the console, the
kernel log buffer, or a syslog socket will still work however.
Defaults to "auto".
Compress=
Takes a boolean value. If enabled (the default), data objects
that shall be stored in the journal and are larger than a certain
threshold are compressed before they are written to the file
system.
Seal=
Takes a boolean value. If enabled (the default), and a sealing
key is available (as created by journalctl(1)'s --setup-keys
command), Forward Secure Sealing (FSS) for all persistent journal
files is enabled. FSS is based on Seekable Sequential Key
Generators[1] by G. A. Marson and B. Poettering
(doi:10.1007/978-3-642-40203-6_7) and may be used to protect
journal files from unnoticed alteration.
SplitMode=
Controls whether to split up journal files per user, either "uid"
or "none". Split journal files are primarily useful for access
control: on UNIX/Linux access control is managed per file, and
the journal daemon will assign users read access to their journal
files. If "uid", all regular users will each get their own
journal files, and system users will log to the system journal.
If "none", journal files are not split up by user and all
messages are instead stored in the single system journal. In this
mode unprivileged users generally do not have access to their own
log data. Note that splitting up journal files by user is only
available for journals stored persistently. If journals are
stored on volatile storage (see Storage= above), only a single
journal file is used. Defaults to "uid".
RateLimitIntervalSec=, RateLimitBurst=
Configures the rate limiting that is applied to all messages
generated on the system. If, in the time interval defined by
RateLimitIntervalSec=, more messages than specified in
RateLimitBurst= are logged by a service, all further messages
within the interval are dropped until the interval is over. A
message about the number of dropped messages is generated. This
rate limiting is applied per-service, so that two services which
log do not interfere with each other's limits. Defaults to 1000
messages in 30s. The time specification for RateLimitIntervalSec=
may be specified in the following units: "s", "min", "h", "ms",
"us". To turn off any kind of rate limiting, set either value to
0.
SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, SystemMaxFiles=,
RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFileSize=,
RuntimeMaxFiles=
Enforce size limits on the journal files stored. The options
prefixed with "System" apply to the journal files when stored on
a persistent file system, more specifically /var/log/journal. The
options prefixed with "Runtime" apply to the journal files when
stored on a volatile in-memory file system, more specifically
/run/log/journal. The former is used only when /var is mounted,
writable, and the directory /var/log/journal exists. Otherwise,
only the latter applies. Note that this means that during early
boot and if the administrator disabled persistent logging, only
the latter options apply, while the former apply if persistent
logging is enabled and the system is fully booted up. journalctl
and systemd-journald ignore all files with names not ending with
".journal" or ".journal~", so only such files, located in the
appropriate directories, are taken into account when calculating
current disk usage.
SystemMaxUse= and RuntimeMaxUse= control how much disk space the
journal may use up at most. SystemKeepFree= and RuntimeKeepFree=
control how much disk space systemd-journald shall leave free for
other uses. systemd-journald will respect both limits and use
the smaller of the two values.
The first pair defaults to 10% and the second to 15% of the size
of the respective file system, but each value is capped to 4G. If
the file system is nearly full and either SystemKeepFree= or
RuntimeKeepFree= are violated when systemd-journald is started,
the limit will be raised to the percentage that is actually free.
This means that if there was enough free space before and journal
files were created, and subsequently something else causes the
file system to fill up, journald will stop using more space, but
it will not be removing existing files to reduce the footprint
again, either.
SystemMaxFileSize= and RuntimeMaxFileSize= control how large
individual journal files may grow at most. This influences the
granularity in which disk space is made available through
rotation, i.e. deletion of historic data. Defaults to one eighth
of the values configured with SystemMaxUse= and RuntimeMaxUse=,
so that usually seven rotated journal files are kept as history.
Specify values in bytes or use K, M, G, T, P, E as units for the
specified sizes (equal to 1024, 1024², ... bytes). Note that size
limits are enforced synchronously when journal files are
extended, and no explicit rotation step triggered by time is
needed.
SystemMaxFiles= and RuntimeMaxFiles= control how many individual
journal files to keep at most. Note that only archived files are
deleted to reduce the number of files until this limit is
reached; active files will stay around. This means that, in
effect, there might still be more journal files around in total
than this limit after a vacuuming operation is complete. This
setting defaults to 100.
MaxFileSec=
The maximum time to store entries in a single journal file before
rotating to the next one. Normally, time-based rotation should
not be required as size-based rotation with options such as
SystemMaxFileSize= should be sufficient to ensure that journal
files do not grow without bounds. However, to ensure that not too
much data is lost at once when old journal files are deleted, it
might make sense to change this value from the default of one
month. Set to 0 to turn off this feature. This setting takes time
values which may be suffixed with the units "year", "month",
"week", "day", "h" or "m" to override the default time unit of
seconds.
MaxRetentionSec=
The maximum time to store journal entries. This controls whether
journal files containing entries older then the specified time
span are deleted. Normally, time-based deletion of old journal
files should not be required as size-based deletion with options
such as SystemMaxUse= should be sufficient to ensure that journal
files do not grow without bounds. However, to enforce data
retention policies, it might make sense to change this value from
the default of 0 (which turns off this feature). This setting
also takes time values which may be suffixed with the units
"year", "month", "week", "day", "h" or " m" to override the
default time unit of seconds.
SyncIntervalSec=
The timeout before synchronizing journal files to disk. After
syncing, journal files are placed in the OFFLINE state. Note that
syncing is unconditionally done immediately after a log message
of priority CRIT, ALERT or EMERG has been logged. This setting
hence applies only to messages of the levels ERR, WARNING,
NOTICE, INFO, DEBUG. The default timeout is 5 minutes.
ForwardToSyslog=, ForwardToKMsg=, ForwardToConsole=, ForwardToWall=
Control whether log messages received by the journal daemon shall
be forwarded to a traditional syslog daemon, to the kernel log
buffer (kmsg), to the system console, or sent as wall messages to
all logged-in users. These options take boolean arguments. If
forwarding to syslog is enabled but nothing reads messages from
the socket, forwarding to syslog has no effect. By default, only
forwarding to wall is enabled. These settings may be overridden
at boot time with the kernel command line options
"systemd.journald.forward_to_syslog",
"systemd.journald.forward_to_kmsg",
"systemd.journald.forward_to_console", and
"systemd.journald.forward_to_wall". If the option name is
specified without "=" and the following argument, true is
assumed. Otherwise, the argument is parsed as a boolean. When
forwarding to the console, the TTY to log to can be changed with
TTYPath=, described below.
MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=,
MaxLevelWall=
Controls the maximum log level of messages that are stored on
disk, forwarded to syslog, kmsg, the console or wall (if that is
enabled, see above). As argument, takes one of "emerg", "alert",
"crit", "err", "warning", "notice", "info", "debug", or integer
values in the range of 0–7 (corresponding to the same levels).
Messages equal or below the log level specified are
stored/forwarded, messages above are dropped. Defaults to "debug"
for MaxLevelStore= and MaxLevelSyslog=, to ensure that the all
messages are written to disk and forwarded to syslog. Defaults to
"notice" for MaxLevelKMsg=, "info" for MaxLevelConsole=, and
"emerg" for MaxLevelWall=. These settings may be overridden at
boot time with the kernel command line options
"systemd.journald.max_level_store=",
"systemd.journald.max_level_syslog=",
"systemd.journald.max_level_kmsg=",
"systemd.journald.max_level_console=",
"systemd.journald.max_level_wall=".
TTYPath=
Change the console TTY to use if ForwardToConsole=yes is used.
Defaults to /dev/console.
Journal events can be transferred to a different logging daemon in
two different ways. With the first method, messages are immediately
forwarded to a socket (/run/systemd/journal/syslog), where the
traditional syslog daemon can read them. This method is controlled by
the ForwardToSyslog= option. With a second method, a syslog daemon
behaves like a normal journal client, and reads messages from the
journal files, similarly to journalctl(1). With this, messages do not
have to be read immediately, which allows a logging daemon which is
only started late in boot to access all messages since the start of
the system. In addition, full structured meta-data is available to
it. This method of course is available only if the messages are
stored in a journal file at all. So it will not work if Storage=none
is set. It should be noted that usually the second method is used by
syslog daemons, so the Storage= option, and not the ForwardToSyslog=
option, is relevant for them.
systemd(1), systemd-journald.service(8), journalctl(1),
systemd.journal-fields(7), systemd-system.conf(5)
1. Seekable Sequential Key Generators
https://eprint.iacr.org/2013/397
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COLOPHON (which is not part of the original manual page), send a mail
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systemd 234 JOURNALD.CONF(5)
Pages that refer to this page: journalctl(1), coredump.conf(5), systemd.directives(7), systemd.index(7), systemd.journal-fields(7), systemd-journald.service(8)