JOURNALD.CONF(5)journald.confJOURNALD.CONF(5)NAMEjournald.conf - Journal service configuration file
SYNOPSIS
/etc/systemd/journald.conf
DESCRIPTION
This file configures various parameters of the systemd journal service,
systemd-journald.service(8).
OPTIONS
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 daemon 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 with the XZ compression algorithm 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. One of
"login", "uid" and "none". If "login", each logged-in user will get
his own journal files, but systemd user IDs will log into the
system journal. If "uid", any user ID will get his own journal
files regardless of whether it belongs to a system service or
refers to a real logged in user. If "none", journal files are not
split up by user and all messages are instead stored in the single
system journal. Note that splitting up journal files by user is
only available for journals stored persistently. If journals are
stored on volatile storage (see above), only a single journal file
for all user IDs is kept. Defaults to "login".
RateLimitInterval=, RateLimitBurst=
Configures the rate limiting that is applied to all messages
generated on the system. If, in the time interval defined by
RateLimitInterval=, 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 200 messages in 10s. The time
specification for RateLimitInterval= 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=, RuntimeMaxUse=,
RuntimeKeepFree=, RuntimeMaxFileSize=
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 maximum. 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. If the file system is nearly full and
either SystemKeepFree= or RuntimeKeepFree= is violated when
systemd-journald is started, the value will be raised to percentage
that is actually free. This means that if before there was enough
free space and journal files were created, and subsequently
something else causes the file system to fill up, journald will
stop using more space, but it'll will not removing existing files
to go reduce footprint either.
SystemMaxFileSize= and RuntimeMaxFileSize= control how large
individual journal files may grow at maximum. 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.
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=
Control whether log messages received by the journal daemon shall
be forwarded to a traditional syslog daemon, to the kernel log
buffer (kmsg), or to the system console. These options take boolean
arguments. If forwarding to syslog is enabled but no syslog daemon
is running, the respective option has no effect. By default, only
forwarding to syslog 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=" and
"systemd.journald.forward_to_console=".
MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=
Controls the maximum log level of messages that are stored on disk,
forwarded to syslog, kmsg or the console (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= and "info" for MaxLevelConsole=.
TTYPath=
Change the console TTY to use if ForwardToConsole=yes is used.
Defaults to /dev/console.
SEE ALSOsystemd(1), systemd-journald.service(8), journalctl(1),
systemd.journal-fields(7), systemd-system.conf(5)NOTES
1. Seekable Sequential Key Generators
https://eprint.iacr.org/2013/397
systemd 208JOURNALD.CONF(5)