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>3</manvolnum></citerefentry></para></listitem>
+ <listitem><para>Structured system log messages via the native Journal API, see
+ <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ and <ulink url="https://systemd.io/JOURNAL_NATIVE_PROTOCOL">Native Journal
+ Protocol</ulink></para></listitem>
<listitem><para>Standard output and standard error of service units. For further details see
below.</para></listitem>
<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> to configure
where log data is placed, independently of the existence of <filename>/var/log/journal/</filename>.</para>
+ <para>Note that journald will initially use volatile storage, until a call to
+ <command>journalctl --flush</command> (or sending <constant>SIGUSR1</constant> to journald) will cause
+ it to switch to persistent logging (under the conditions mentioned above). This is done automatically
+ on boot via <literal>systemd-journal-flush.service</literal>.</para>
+
<para>On systems where <filename>/var/log/journal/</filename> does not exist yet but where persistent logging is
desired (and the default <filename>journald.conf</filename> is used), it is sufficient to create the directory, and
ensure it has the correct access modes and ownership:</para>