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Double newlines (i.e. one empty lines) are great to structure code. But let's avoid triple newlines (i.e. two empty lines), quadruple newlines, quintuple newlines, …, that's just spurious whitespace. It's an easy way to drop 121 lines of code, and keeps the coding style of our sources a bit tigther.
429 lines
21 KiB
XML
429 lines
21 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!--
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SPDX-License-Identifier: LGPL-2.1+
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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-->
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<refentry id="journald.conf"
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xmlns:xi="http://www.w3.org/2001/XInclude">
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<refentryinfo>
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<title>journald.conf</title>
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<productname>systemd</productname>
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<authorgroup>
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<author>
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<contrib>Developer</contrib>
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<firstname>Lennart</firstname>
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<surname>Poettering</surname>
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<email>lennart@poettering.net</email>
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</author>
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</authorgroup>
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</refentryinfo>
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<refmeta>
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<refentrytitle>journald.conf</refentrytitle>
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<manvolnum>5</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>journald.conf</refname>
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<refname>journald.conf.d</refname>
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<refpurpose>Journal service configuration files</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<para><filename>/etc/systemd/journald.conf</filename></para>
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<para><filename>/etc/systemd/journald.conf.d/*.conf</filename></para>
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<para><filename>/run/systemd/journald.conf.d/*.conf</filename></para>
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<para><filename>/usr/lib/systemd/journald.conf.d/*.conf</filename></para>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>These files configure various parameters of the systemd journal service,
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<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
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See
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<citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>5</manvolnum></citerefentry>
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for a general description of the syntax.</para>
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</refsect1>
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<xi:include href="standard-conf.xml" xpointer="main-conf" />
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<refsect1>
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<title>Options</title>
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<para>All options are configured in the
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<literal>[Journal]</literal> section:</para>
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<variablelist>
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<varlistentry>
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<term><varname>Storage=</varname></term>
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<listitem><para>Controls where to store journal data. One of
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<literal>volatile</literal>,
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<literal>persistent</literal>,
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<literal>auto</literal> and
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<literal>none</literal>. If
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<literal>volatile</literal>, journal
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log data will be stored only in memory, i.e. below the
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<filename>/run/log/journal</filename> hierarchy (which is
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created if needed). If <literal>persistent</literal>, data
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will be stored preferably on disk, i.e. below the
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<filename>/var/log/journal</filename> hierarchy (which is
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created if needed), with a fallback to
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<filename>/run/log/journal</filename> (which is created if
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needed), during early boot and if the disk is not writable.
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<literal>auto</literal> is similar to
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<literal>persistent</literal> but the directory
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<filename>/var/log/journal</filename> is not created if
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needed, so that its existence controls where log data goes.
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<literal>none</literal> turns off all storage, all log data
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received will be dropped. Forwarding to other targets, such as
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the console, the kernel log buffer, or a syslog socket will
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still work however. Defaults to
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<literal>auto</literal>.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>Compress=</varname></term>
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<listitem><para>Can take a boolean value. If enabled (the
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default), data objects that shall be stored in the journal
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and are larger than the default threshold of 512 bytes are
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compressed before they are written to the file system. It
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can also be set to a number of bytes to specify the
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compression threshold directly. Suffixes like K, M, and G
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can be used to specify larger units.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>Seal=</varname></term>
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<listitem><para>Takes a boolean value. If enabled (the
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default), and a sealing key is available (as created by
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<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
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<option>--setup-keys</option> command), Forward Secure Sealing
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(FSS) for all persistent journal files is enabled. FSS is
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based on <ulink
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url="https://eprint.iacr.org/2013/397">Seekable Sequential Key
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Generators</ulink> by G. A. Marson and B. Poettering
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(doi:10.1007/978-3-642-40203-6_7) and may be used to protect
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journal files from unnoticed alteration.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>SplitMode=</varname></term>
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<listitem><para>Controls whether to split up journal files per user, either <literal>uid</literal> or
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<literal>none</literal>. Split journal files are primarily useful for access control: on UNIX/Linux access
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control is managed per file, and the journal daemon will assign users read access to their journal files. If
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<literal>uid</literal>, all regular users will each get their own journal files, and system users will log to
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the system journal. If <literal>none</literal>, journal files are not split up by user and all messages are
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instead stored in the single system journal. In this mode unprivileged users generally do not have access to
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their own log data. Note that splitting up journal files by user is only available for journals stored
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persistently. If journals are stored on volatile storage (see <varname>Storage=</varname> above), only a single
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journal file is used. Defaults to <literal>uid</literal>.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>RateLimitIntervalSec=</varname></term>
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<term><varname>RateLimitBurst=</varname></term>
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<listitem><para>Configures the rate limiting that is applied
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to all messages generated on the system. If, in the time
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interval defined by <varname>RateLimitIntervalSec=</varname>,
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more messages than specified in
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<varname>RateLimitBurst=</varname> are logged by a service,
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all further messages within the interval are dropped until the
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interval is over. A message about the number of dropped
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messages is generated. This rate limiting is applied
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per-service, so that two services which log do not interfere
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with each other's limits. Defaults to 10000 messages in 30s.
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The time specification for
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<varname>RateLimitIntervalSec=</varname> may be specified in the
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following units: <literal>s</literal>, <literal>min</literal>,
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<literal>h</literal>, <literal>ms</literal>,
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<literal>us</literal>. To turn off any kind of rate limiting,
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set either value to 0.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>SystemMaxUse=</varname></term>
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<term><varname>SystemKeepFree=</varname></term>
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<term><varname>SystemMaxFileSize=</varname></term>
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<term><varname>SystemMaxFiles=</varname></term>
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<term><varname>RuntimeMaxUse=</varname></term>
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<term><varname>RuntimeKeepFree=</varname></term>
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<term><varname>RuntimeMaxFileSize=</varname></term>
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<term><varname>RuntimeMaxFiles=</varname></term>
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<listitem><para>Enforce size limits on the journal files
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stored. The options prefixed with <literal>System</literal>
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apply to the journal files when stored on a persistent file
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system, more specifically
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<filename>/var/log/journal</filename>. The options prefixed
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with <literal>Runtime</literal> apply to the journal files
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when stored on a volatile in-memory file system, more
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specifically <filename>/run/log/journal</filename>. The former
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is used only when <filename>/var</filename> is mounted,
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writable, and the directory
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<filename>/var/log/journal</filename> exists. Otherwise, only
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the latter applies. Note that this means that during early
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boot and if the administrator disabled persistent logging,
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only the latter options apply, while the former apply if
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persistent logging is enabled and the system is fully booted
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up. <command>journalctl</command> and
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<command>systemd-journald</command> ignore all files with
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names not ending with <literal>.journal</literal> or
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<literal>.journal~</literal>, so only such files, located in
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the appropriate directories, are taken into account when
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calculating current disk usage.</para>
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<para><varname>SystemMaxUse=</varname> and
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<varname>RuntimeMaxUse=</varname> control how much disk space
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the journal may use up at most.
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<varname>SystemKeepFree=</varname> and
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<varname>RuntimeKeepFree=</varname> control how much disk
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space systemd-journald shall leave free for other uses.
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<command>systemd-journald</command> will respect both limits
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and use the smaller of the two values.</para>
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<para>The first pair defaults to 10% and the second to 15% of
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the size of the respective file system, but each value is
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capped to 4G. If the file system is nearly full and either
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<varname>SystemKeepFree=</varname> or
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<varname>RuntimeKeepFree=</varname> are violated when
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systemd-journald is started, the limit will be raised to the
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percentage that is actually free. This means that if there was
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enough free space before and journal files were created, and
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subsequently something else causes the file system to fill up,
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journald will stop using more space, but it will not be
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removing existing files to reduce the footprint again,
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either.</para>
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<para><varname>SystemMaxFileSize=</varname> and
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<varname>RuntimeMaxFileSize=</varname> control how large
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individual journal files may grow at most. This influences
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the granularity in which disk space is made available through
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rotation, i.e. deletion of historic data. Defaults to one
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eighth of the values configured with
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<varname>SystemMaxUse=</varname> and
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<varname>RuntimeMaxUse=</varname>, so that usually seven
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rotated journal files are kept as history.</para>
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<para>Specify values in bytes or use K, M, G, T, P, E as
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units for the specified sizes (equal to 1024, 1024², … bytes).
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Note that size limits are enforced synchronously when journal
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files are extended, and no explicit rotation step triggered by
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time is needed.</para>
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<para><varname>SystemMaxFiles=</varname> and
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<varname>RuntimeMaxFiles=</varname> control how many
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individual journal files to keep at most. Note that only
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archived files are deleted to reduce the number of files until
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this limit is reached; active files will stay around. This
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means that, in effect, there might still be more journal files
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around in total than this limit after a vacuuming operation is
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complete. This setting defaults to 100.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MaxFileSec=</varname></term>
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<listitem><para>The maximum time to store entries in a single
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journal file before rotating to the next one. Normally,
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time-based rotation should not be required as size-based
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rotation with options such as
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<varname>SystemMaxFileSize=</varname> should be sufficient to
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ensure that journal files do not grow without bounds. However,
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to ensure that not too much data is lost at once when old
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journal files are deleted, it might make sense to change this
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value from the default of one month. Set to 0 to turn off this
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feature. This setting takes time values which may be suffixed
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with the units <literal>year</literal>,
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<literal>month</literal>, <literal>week</literal>,
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<literal>day</literal>, <literal>h</literal> or
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<literal>m</literal> to override the default time unit of
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seconds.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MaxRetentionSec=</varname></term>
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<listitem><para>The maximum time to store journal entries.
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This controls whether journal files containing entries older
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then the specified time span are deleted. Normally, time-based
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deletion of old journal files should not be required as
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size-based deletion with options such as
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<varname>SystemMaxUse=</varname> should be sufficient to
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ensure that journal files do not grow without bounds. However,
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to enforce data retention policies, it might make sense to
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change this value from the default of 0 (which turns off this
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feature). This setting also takes time values which may be
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suffixed with the units <literal>year</literal>,
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<literal>month</literal>, <literal>week</literal>,
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<literal>day</literal>, <literal>h</literal> or <literal>
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m</literal> to override the default time unit of
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seconds.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>SyncIntervalSec=</varname></term>
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<listitem><para>The timeout before synchronizing journal files
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to disk. After syncing, journal files are placed in the
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OFFLINE state. Note that syncing is unconditionally done
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immediately after a log message of priority CRIT, ALERT or
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EMERG has been logged. This setting hence applies only to
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messages of the levels ERR, WARNING, NOTICE, INFO, DEBUG. The
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default timeout is 5 minutes. </para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ForwardToSyslog=</varname></term>
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<term><varname>ForwardToKMsg=</varname></term>
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<term><varname>ForwardToConsole=</varname></term>
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<term><varname>ForwardToWall=</varname></term>
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<listitem><para>Control whether log messages received by the journal daemon shall
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be forwarded to a traditional syslog daemon, to the kernel log buffer (kmsg), to
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the system console, or sent as wall messages to all logged-in users. These
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options take boolean arguments. If forwarding to syslog is enabled but nothing
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reads messages from the socket, forwarding to syslog has no effect. By default,
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only forwarding to wall is enabled. These settings may be overridden at boot time
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with the kernel command line options
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<literal>systemd.journald.forward_to_syslog</literal>,
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<literal>systemd.journald.forward_to_kmsg</literal>,
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<literal>systemd.journald.forward_to_console</literal>, and
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<literal>systemd.journald.forward_to_wall</literal>. If the option name is
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specified without <literal>=</literal> and the following argument, true is
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assumed. Otherwise, the argument is parsed as a boolean. When forwarding to the
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console, the TTY to log to can be changed with <varname>TTYPath=</varname>,
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described below.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MaxLevelStore=</varname></term>
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<term><varname>MaxLevelSyslog=</varname></term>
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<term><varname>MaxLevelKMsg=</varname></term>
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<term><varname>MaxLevelConsole=</varname></term>
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<term><varname>MaxLevelWall=</varname></term>
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<listitem><para>Controls the maximum log level of messages
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that are stored on disk, forwarded to syslog, kmsg, the
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console or wall (if that is enabled, see above). As argument,
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takes one of
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<literal>emerg</literal>,
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<literal>alert</literal>,
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<literal>crit</literal>,
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<literal>err</literal>,
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<literal>warning</literal>,
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<literal>notice</literal>,
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<literal>info</literal>,
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<literal>debug</literal>,
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or integer values in the range of 0–7 (corresponding to the
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same levels). Messages equal or below the log level specified
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are stored/forwarded, messages above are dropped. Defaults to
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<literal>debug</literal> for <varname>MaxLevelStore=</varname>
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and <varname>MaxLevelSyslog=</varname>, to ensure that the all
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messages are written to disk and forwarded to syslog. Defaults
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to
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<literal>notice</literal> for <varname>MaxLevelKMsg=</varname>,
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<literal>info</literal> for <varname>MaxLevelConsole=</varname>,
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and <literal>emerg</literal> for
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<varname>MaxLevelWall=</varname>. These settings may be
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overridden at boot time with the kernel command line options
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<literal>systemd.journald.max_level_store=</literal>,
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<literal>systemd.journald.max_level_syslog=</literal>,
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<literal>systemd.journald.max_level_kmsg=</literal>,
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<literal>systemd.journald.max_level_console=</literal>,
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<literal>systemd.journald.max_level_wall=</literal>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ReadKMsg=</varname></term>
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<listitem><para>Takes a boolean value. If enabled (the
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||
default), journal reads <filename>/dev/kmsg</filename>
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messages generated by the kernel.</para></listitem>
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</varlistentry>
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<varlistentry>
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||
<term><varname>TTYPath=</varname></term>
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||
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<listitem><para>Change the console TTY to use if
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<varname>ForwardToConsole=yes</varname> is used. Defaults to
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<filename>/dev/console</filename>.</para></listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><varname>LineMax=</varname></term>
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||
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<listitem><para>The maximum line length to permit when converting stream logs into record logs. When a systemd
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||
unit's standard output/error are connected to the journal via a stream socket, the data read is split into
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||
individual log records at newline (<literal>\n</literal>, ASCII 10) and NUL characters. If no such delimiter is
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read for the specified number of bytes a hard log record boundary is artificially inserted, breaking up overly
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||
long lines into multiple log records. Selecting overly large values increases the possible memory usage of the
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Journal daemon for each stream client, as in the worst case the journal daemon needs to buffer the specified
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||
number of bytes in memory before it can flush a new log record to disk. Also note that permitting overly large
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||
line maximum line lengths affects compatibility with traditional log protocols as log records might not fit
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||
anymore into a single <constant>AF_UNIX</constant> or <constant>AF_INET</constant> datagram. Takes a size in
|
||
bytes. If the value is suffixed with K, M, G or T, the specified size is parsed as Kilobytes, Megabytes,
|
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Gigabytes, or Terabytes (with the base 1024), respectively. Defaults to 48K, which is relatively large but
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||
still small enough so that log records likely fit into network datagrams along with extra room for
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||
metadata. Note that values below 79 are not accepted and will be bumped to 79.</para></listitem>
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||
</varlistentry>
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||
</variablelist>
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||
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</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Forwarding to traditional syslog daemons</title>
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||
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||
<para>
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||
Journal events can be transferred to a different logging daemon
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||
in two different ways. With the first method, messages are
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||
immediately forwarded to a socket
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||
(<filename>/run/systemd/journal/syslog</filename>), where the
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||
traditional syslog daemon can read them. This method is
|
||
controlled by the <varname>ForwardToSyslog=</varname> option. With a
|
||
second method, a syslog daemon behaves like a normal journal
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||
client, and reads messages from the journal files, similarly to
|
||
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||
With this, messages do not have to be read immediately,
|
||
which allows a logging daemon which is only started late in boot
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||
to access all messages since the start of the system. In
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||
addition, full structured meta-data is available to it. This
|
||
method of course is available only if the messages are stored in
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||
a journal file at all. So it will not work if
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<varname>Storage=none</varname> is set. It should be noted that
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||
usually the <emphasis>second</emphasis> method is used by syslog
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||
daemons, so the <varname>Storage=</varname> option, and not the
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<varname>ForwardToSyslog=</varname> option, is relevant for them.
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||
</para>
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||
</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>
|