systemd-journald.service.xml revision 01cf0ca850dd1c21e1c405a4493fe61d0c28d721
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<refentry id="systemd-journald.service">
<refentryinfo>
<title>systemd-journald</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</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-journald.service</refname>
<refname>systemd-journald</refname>
<refpurpose>systemd Journal Service</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd-journald.service</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 the kernel, from user processes via the libc
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
call, from STDOUT/STDERR of system services or via its
native API. It will implicitly collect numerous meta
data 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 meta data.
</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 persistant it
is sufficient to create
<filename>/var/log/journal/</filename> where
<filename>systemd-journald</filename> will then store
the data.</para>
<para><filename>systemd-journald</filename> will
forward all received log messages to the AF_UNIX
SOCK_DGRAM socket
<filename>/run/systemd/journal/syslog</filename> (if it exists) which
may be used by UNIX syslog daemons to process the data
further.</para>
<para>See
<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for information about the configuration of this
service.</para>
</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>
</para>
</refsect1>
</refentry>