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systemd-stable/man/journald.conf.xml
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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
<!ENTITY % entities SYSTEM "custom-entities.ent" >
%entities;
]>
<!--
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
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You should have received a copy of the GNU Lesser General Public License
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-->
<refentry id="journald.conf"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>journald.conf</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>journald.conf</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>journald.conf</refname>
<refname>journald.conf.d</refname>
<refpurpose>Journal service configuration files</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>&pkgsysconfdir;/journald.conf</filename></para>
<para><filename>&pkgsysconfdir;/journald.conf.d/*.conf</filename></para>
<para><filename>/run/systemd/journald.conf.d/*.conf</filename></para>
<para><filename>&rootlibexecdir;/journald.conf.d/*.conf</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>These files configure various parameters of the systemd
journal service,
<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</refsect1>
<xi:include href="standard-conf.xml" xpointer="main-conf" />
<refsect1>
<title>Options</title>
<para>All options are configured in the
<literal>[Journal]</literal> section:</para>
<variablelist>
<varlistentry>
<term><varname>Storage=</varname></term>
<listitem><para>Controls where to store journal data. One of
<literal>volatile</literal>,
<literal>persistent</literal>,
<literal>auto</literal> and
<literal>none</literal>. If
<literal>volatile</literal>, journal
log data will be stored only in memory, i.e. below the
<filename>/run/log/journal</filename> hierarchy (which is
created if needed). If <literal>persistent</literal>, data
will be stored preferably on disk, i.e. below the
<filename>/var/log/journal</filename> hierarchy (which is
created if needed), with a fallback to
<filename>/run/log/journal</filename> (which is created if
needed), during early boot and if the disk is not writable.
<literal>auto</literal> is similar to
<literal>persistent</literal> but the directory
<filename>/var/log/journal</filename> is not created if
needed, so that its existence controls where log data goes.
<literal>none</literal> 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
<literal>auto</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>Compress=</varname></term>
<listitem><para>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.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>Seal=</varname></term>
<listitem><para>Takes a boolean value. If enabled (the
default), and a sealing key is available (as created by
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
<option>--setup-keys</option> command), Forward Secure Sealing
(FSS) for all persistent journal files is enabled. FSS is
based on <ulink
url="https://eprint.iacr.org/2013/397">Seekable Sequential Key
Generators</ulink> 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.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>SplitMode=</varname></term>
<listitem><para>Controls whether to split up journal files per
user. One of <literal>uid</literal>, <literal>login</literal>
and <literal>none</literal>. If <literal>uid</literal>, all
users will get each their own journal files regardless of
whether they possess a login session or not, however system
users will log into the system journal. If
<literal>login</literal>, actually logged-in users will get
each their own journal files, but users without login session
and system users will log into the system journal. If
<literal>none</literal>, 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
<literal>uid</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>RateLimitInterval=</varname></term>
<term><varname>RateLimitBurst=</varname></term>
<listitem><para>Configures the rate limiting that is applied
to all messages generated on the system. If, in the time
interval defined by <varname>RateLimitInterval=</varname>,
more messages than specified in
<varname>RateLimitBurst=</varname> 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
<varname>RateLimitInterval=</varname> may be specified in the
following units: <literal>s</literal>, <literal>min</literal>,
<literal>h</literal>, <literal>ms</literal>,
<literal>us</literal>. To turn off any kind of rate limiting,
set either value to 0.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>SystemMaxUse=</varname></term>
<term><varname>SystemKeepFree=</varname></term>
<term><varname>SystemMaxFileSize=</varname></term>
<term><varname>RuntimeMaxUse=</varname></term>
<term><varname>RuntimeKeepFree=</varname></term>
<term><varname>RuntimeMaxFileSize=</varname></term>
<listitem><para>Enforce size limits on the journal files
stored. The options prefixed with <literal>System</literal>
apply to the journal files when stored on a persistent file
system, more specifically
<filename>/var/log/journal</filename>. The options prefixed
with <literal>Runtime</literal> apply to the journal files
when stored on a volatile in-memory file system, more
specifically <filename>/run/log/journal</filename>. The former
is used only when <filename>/var</filename> is mounted,
writable, and the directory
<filename>/var/log/journal</filename> 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. <command>journalctl</command> and
<command>systemd-journald</command> ignore all files with
names not ending with <literal>.journal</literal> or
<literal>.journal~</literal>, so only such files, located in
the appropriate directories, are taken into account when
calculating current disk usage.
</para>
<para><varname>SystemMaxUse=</varname> and
<varname>RuntimeMaxUse=</varname> control how much disk space
the journal may use up at maximum.
<varname>SystemKeepFree=</varname> and
<varname>RuntimeKeepFree=</varname> control how much disk
space systemd-journald shall leave free for other uses.
<command>systemd-journald</command> will respect both limits
and use the smaller of the two values.</para>
<para>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 <varname>SystemKeepFree=</varname> or
<varname>RuntimeKeepFree=</varname> is violated when
systemd-journald is started, the value will be raised to
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 go reduce footprint either.</para>
<para><varname>SystemMaxFileSize=</varname> and
<varname>RuntimeMaxFileSize=</varname> 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
<varname>SystemMaxUse=</varname> and
<varname>RuntimeMaxUse=</varname>, so that usually seven
rotated journal files are kept as history.</para></listitem>
<para>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.</para>
</varlistentry>
<varlistentry>
<term><varname>MaxFileSec=</varname></term>
<listitem><para>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
<varname>SystemMaxFileSize=</varname> 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 <literal>year</literal>,
<literal>month</literal>, <literal>week</literal>,
<literal>day</literal>, <literal>h</literal> or
<literal>m</literal> to override the default time unit of
seconds.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>MaxRetentionSec=</varname></term>
<listitem><para>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
<varname>SystemMaxUse=</varname> 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 <literal>year</literal>,
<literal>month</literal>, <literal>week</literal>,
<literal>day</literal>, <literal>h</literal> or <literal>
m</literal> to override the default time unit of
seconds.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>SyncIntervalSec=</varname></term>
<listitem><para>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. </para></listitem>
</varlistentry>
<varlistentry>
<term><varname>ForwardToSyslog=</varname></term>
<term><varname>ForwardToKMsg=</varname></term>
<term><varname>ForwardToConsole=</varname></term>
<term><varname>ForwardToWall=</varname></term>
<listitem><para>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
<literal>systemd.journald.forward_to_syslog=</literal>,
<literal>systemd.journald.forward_to_kmsg=</literal>,
<literal>systemd.journald.forward_to_console=</literal>, and
<literal>systemd.journald.forward_to_wall=</literal>. When
forwarding to the console, the TTY to log to can be changed
with <varname>TTYPath=</varname>, described
below.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>MaxLevelStore=</varname></term>
<term><varname>MaxLevelSyslog=</varname></term>
<term><varname>MaxLevelKMsg=</varname></term>
<term><varname>MaxLevelConsole=</varname></term>
<term><varname>MaxLevelWall=</varname></term>
<listitem><para>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
<literal>emerg</literal>,
<literal>alert</literal>,
<literal>crit</literal>,
<literal>err</literal>,
<literal>warning</literal>,
<literal>notice</literal>,
<literal>info</literal>,
<literal>debug</literal>,
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
<literal>debug</literal> for <varname>MaxLevelStore=</varname>
and <varname>MaxLevelSyslog=</varname>, to ensure that the all
messages are written to disk and forwarded to syslog. Defaults
to
<literal>notice</literal> for <varname>MaxLevelKMsg=</varname>,
<literal>info</literal> for <varname>MaxLevelConsole=</varname>,
and <literal>emerg</literal> for
<varname>MaxLevelWall=</varname>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>TTYPath=</varname></term>
<listitem><para>Change the console TTY to use if
<varname>ForwardToConsole=yes</varname> is used. Defaults to
<filename>/dev/console</filename>.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Forwarding to traditional syslog daemons</title>
<para>
Journal events can be transferred to a different logging daemon
in two different ways. In the first method, messages are
immediately forwarded to a socket
(<filename>/run/systemd/journal/syslog</filename>), where the
traditional syslog daemon can read them. This method is
controlled by <varname>ForwardToSyslog=</varname> option. In a
second method, a syslog daemon behaves like a normal journal
client, and reads messages from the journal files, similarly to
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
In this method, 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
<varname>Storage=none</varname> is set. It should be noted that
usually the <emphasis>second</emphasis> method is used by syslog
daemons, so the <varname>Storage=</varname> option, and not the
<varname>ForwardToSyslog=</varname> option, is relevant for them.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
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