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Diffstat (limited to 'src/grp-journal/systemd-journald/systemd-journald.service.xml')
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diff --git a/src/grp-journal/systemd-journald/systemd-journald.service.xml b/src/grp-journal/systemd-journald/systemd-journald.service.xml new file mode 100644 index 0000000000..2810638bc2 --- /dev/null +++ b/src/grp-journal/systemd-journald/systemd-journald.service.xml @@ -0,0 +1,276 @@ +<?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"> + +<!-- + 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 + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="systemd-journald.service"> + + <refentryinfo> + <title>systemd-journald.service</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>systemd-journald.service</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-journald.service</refname> + <refname>systemd-journald.socket</refname> + <refname>systemd-journald-dev-log.socket</refname> + <refname>systemd-journald-audit.socket</refname> + <refname>systemd-journald</refname> + <refpurpose>Journal service</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>systemd-journald.service</filename></para> + <para><filename>systemd-journald.socket</filename></para> + <para><filename>systemd-journald-dev-log.socket</filename></para> + <para><filename>systemd-journald-audit.socket</filename></para> + <para><filename>/usr/lib/systemd/systemd-journald</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>systemd-journald</filename> is a system service + that collects and stores logging data. It creates and maintains + structured, indexed journals based on logging information that is + received from a variety of sources:</para> + + <itemizedlist> + <listitem><para>Kernel log messages, via kmsg</para></listitem> + + <listitem><para>Simple system log messages, via the libc + <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> + call</para></listitem> + + <listitem><para>Structured system log messages via the native + Journal API, see + <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>4</manvolnum></citerefentry></para></listitem> + + <listitem><para>Standard output and standard error of system + services</para></listitem> + + <listitem><para>Audit records, via the audit + subsystem</para></listitem> + </itemizedlist> + + <para>The daemon will implicitly collect numerous metadata fields + for each log messages in a secure and unfakeable way. See + <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for more information about the collected metadata. + </para> + + <para>Log data collected by the journal is primarily text-based + but can also include binary data where necessary. All objects + stored in the journal can be up to 2^64-1 bytes in size.</para> + + <para>By default, the journal stores log data in + <filename>/run/log/journal/</filename>. Since + <filename>/run/</filename> is volatile, log data is lost at + reboot. To make the data persistent, it is sufficient to create + <filename>/var/log/journal/</filename> where + <filename>systemd-journald</filename> will then store the + data:</para> + + <programlisting>mkdir -p /var/log/journal +systemd-tmpfiles --create --prefix /var/log/journal</programlisting> + + <para>See + <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for information about the configuration of this service.</para> + </refsect1> + + <refsect1> + <title>Signals</title> + + <variablelist> + <varlistentry> + <term>SIGUSR1</term> + + <listitem><para>Request that journal data from + <filename>/run/</filename> is flushed to + <filename>/var/</filename> in order to make it persistent (if + this is enabled). This must be used after + <filename>/var/</filename> is mounted, as otherwise log data + from <filename>/run</filename> is never flushed to + <filename>/var</filename> regardless of the configuration. The + <command>journalctl --flush</command> command uses this signal + to request flushing of the journal files, and then waits for + the operation to complete. See + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + for details.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGUSR2</term> + + <listitem><para>Request immediate rotation of the journal + files. The <command>journalctl --rotate</command> command uses + this signal to request journal file + rotation.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+1</term> + + <listitem><para>Request that all unwritten log data is written + to disk. The <command>journalctl --sync</command> command uses + this signal to trigger journal synchronization, and then waits + for the operation to complete.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Kernel Command Line</title> + + <para>A few configuration parameters from + <filename>journald.conf</filename> may be overridden on the kernel + command line:</para> + + <variablelist class='kernel-commandline-options'> + <varlistentry> + <term><varname>systemd.journald.forward_to_syslog=</varname></term> + <term><varname>systemd.journald.forward_to_kmsg=</varname></term> + <term><varname>systemd.journald.forward_to_console=</varname></term> + <term><varname>systemd.journald.forward_to_wall=</varname></term> + + <listitem><para>Enables/disables forwarding of collected log + messages to syslog, the kernel log buffer, the system console + or wall. + </para> + + <para>See + <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for information about these settings.</para> + </listitem> + + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Access Control</title> + + <para>Journal files are, by default, owned and readable by the + <literal>systemd-journal</literal> system group but are not + writable. Adding a user to this group thus enables her/him to read + the journal files.</para> + + <para>By default, each logged in user will get her/his own set of + journal files in <filename>/var/log/journal/</filename>. These + files will not be owned by the user, however, in order to avoid + that the user can write to them directly. Instead, file system + ACLs are used to ensure the user gets read access only.</para> + + <para>Additional users and groups may be granted access to journal + files via file system access control lists (ACL). Distributions + and administrators may choose to grant read access to all members + of the <literal>wheel</literal> and <literal>adm</literal> system + groups with a command such as the following:</para> + + <programlisting># setfacl -Rnm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/</programlisting> + + <para>Note that this command will update the ACLs both for + existing journal files and for future journal files created in the + <filename>/var/log/journal/</filename> directory.</para> + </refsect1> + + <refsect1> + <title>Files</title> + + <variablelist> + <varlistentry> + <term><filename>/etc/systemd/journald.conf</filename></term> + + <listitem><para>Configure + <command>systemd-journald</command> + behavior. See + <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><filename>/run/log/journal/<replaceable>machine-id</replaceable>/*.journal</filename></term> + <term><filename>/run/log/journal/<replaceable>machine-id</replaceable>/*.journal~</filename></term> + <term><filename>/var/log/journal/<replaceable>machine-id</replaceable>/*.journal</filename></term> + <term><filename>/var/log/journal/<replaceable>machine-id</replaceable>/*.journal~</filename></term> + + <listitem><para><command>systemd-journald</command> writes + entries to files in + <filename>/run/log/journal/<replaceable>machine-id</replaceable>/</filename> + or + <filename>/var/log/journal/<replaceable>machine-id</replaceable>/</filename> + with the <literal>.journal</literal> suffix. If the daemon is + stopped uncleanly, or if the files are found to be corrupted, + they are renamed using the <literal>.journal~</literal> + suffix, and <command>systemd-journald</command> starts writing + to a new file. <filename>/run</filename> is used when + <filename>/var/log/journal</filename> is not available, or + when <option>Storage=volatile</option> is set in the + <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + configuration file.</para></listitem> + </varlistentry> + + <varlistentry> + <term><filename>/dev/kmsg</filename></term> + <term><filename>/dev/log</filename></term> + <term><filename>/run/systemd/journal/dev-log</filename></term> + <term><filename>/run/systemd/journal/socket</filename></term> + <term><filename>/run/systemd/journal/stdout</filename></term> + + <listitem><para>Sockets and other paths that + <command>systemd-journald</command> will listen on that are + visible in the file system. In addition to these, journald can + listen for audit events using netlink.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry project='die-net'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>4</manvolnum></citerefentry>, + <command>pydoc systemd.journal</command> + </para> + </refsect1> + +</refentry> |