diff options
Diffstat (limited to 'man/systemd-journald.service.xml')
| -rw-r--r-- | man/systemd-journald.service.xml | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/man/systemd-journald.service.xml b/man/systemd-journald.service.xml index fec0e1fe88..8ca0e896ab 100644 --- a/man/systemd-journald.service.xml +++ b/man/systemd-journald.service.xml @@ -3,6 +3,8 @@ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- + SPDX-License-Identifier: LGPL-2.1+ + This file is part of systemd. Copyright 2010 Lennart Poettering @@ -90,17 +92,19 @@ 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>Log data collected by the journal is primarily text-based but can also include binary data where + necessary. Individual fields making up a log record stored in the journal may be up to 2^64-1 bytes in size.</para> + + <para>The journal service stores log data either persistently below <filename>/var/log/journal</filename> or in a + volatile way below <filename>/run/log/journal/</filename> (in the latter case it is lost at reboot). By default, log + data is stored persistently if <filename>/var/log/journal/</filename> exists during boot, with an implicit fallback + to volatile storage otherwise. Use <varname>Storage=</varname> in + <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>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> + <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> <programlisting>mkdir -p /var/log/journal systemd-tmpfiles --create --prefix /var/log/journal</programlisting> @@ -123,7 +127,7 @@ systemd-tmpfiles --create --prefix /var/log/journal</programlisting> <para>If <filename>systemd-journald.service</filename> is stopped, the stream connections associated with all services are terminated. Further writes to those streams by the service will result in <constant>EPIPE</constant> errors. In order to react gracefully in this case it is recommended that programs logging to standard output/error - ignore such errors. If the the <constant>SIGPIPE</constant> UNIX signal handler is not blocked or turned off, such + ignore such errors. If the <constant>SIGPIPE</constant> UNIX signal handler is not blocked or turned off, such write attempts will also result in such process signals being generated, see <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>. To mitigate this issue, systemd service manager explicitly turns off the <constant>SIGPIPE</constant> signal for all invoked processes by @@ -145,12 +149,12 @@ systemd-tmpfiles --create --prefix /var/log/journal</programlisting> transports listed above, which are inherently record based and where the metadata is always associated with the individual record.</para> - <para>In addition to the the implicit standard output/error logging of services, stream logging is also available + <para>In addition to the implicit standard output/error logging of services, stream logging is also available via the <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry> command line tool.</para> <para>Currently, the number of parallel log streams <filename>systemd-journald</filename> will accept is limited to - 4096. When this limit is reached further log streams may be established but will receieve + 4096. When this limit is reached further log streams may be established but will receive <constant>EPIPE</constant> right from the beginning.</para> </refsect1> |