path: root/man/journald.conf.xml

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<refentry id="journald.conf">
        <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>
                <refpurpose>Journal service configuration file</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <para><filename>/etc/systemd/journald.conf</filename></para>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para>This file configures various parameters of the
                systemd journal service,
                <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

        </refsect1>

        <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 daemon
                                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 with the XZ
                                compression algorithm 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. 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></listitem>
                        </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 no
                                syslog daemon is running, the
                                respective option has no effect. By
                                default, only forwarding 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>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>