diff options
Diffstat (limited to 'man/systemd-coredump.xml')
| -rw-r--r-- | man/systemd-coredump.xml | 98 |
1 files changed, 58 insertions, 40 deletions
diff --git a/man/systemd-coredump.xml b/man/systemd-coredump.xml index 51dc27e8d3..a28dc62e5a 100644 --- a/man/systemd-coredump.xml +++ b/man/systemd-coredump.xml @@ -47,7 +47,7 @@ <refname>systemd-coredump</refname> <refname>systemd-coredump.socket</refname> <refname>systemd-coredump@.service</refname> - <refpurpose>Log and store core dumps</refpurpose> + <refpurpose>Acquire, save and process core dumps</refpurpose> </refnamediv> <refsynopsisdiv> @@ -58,59 +58,76 @@ <refsect1> <title>Description</title> + <para><command>systemd-coredump</command> is a system service that can acquire core dumps + from the kernel and handle them in various ways.</para> - <para><command>systemd-coredump</command> can be used as a helper - binary by the kernel when a user space program receives a fatal - signal and dumps core. For it to be used in this capacity, it must - be specified by the - <varname>kernel.core_pattern</varname> <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> - setting. The syntax of this setting is explained in - <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>. - Systemd installs <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> which configures - <varname>kernel.core_pattern</varname> to invoke <command>systemd-coredump</command>. - This file may be masked or overridden to use a different setting following normal - <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> - rules.</para> - - <para>The behavior of a specific program upon reception of a - signal is governed by a few factors which are described in detail - in <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>. - In particular, the coredump will only be processed when the - related resource limits are high enough. For programs started by - <command>systemd</command>, those may be set using - <varname>LimitCore=</varname> (see - <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>). + <para>Core dumps can be written to the journal or saved as a file. Once saved they can be retrieved + for further processing, for example in + <citerefentry project='man-pages'><refentrytitle>gdb</refentrytitle><manvolnum>1</manvolnum></citerefentry>. </para> - <para>The behaviour of <command>systemd-coredump</command> is configured through - <filename>/etc/systemd/coredump.conf</filename> and other configuration files. See - <citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details. By default, <command>systemd-coredump</command> will log the coredump including a - backtrace if possible, and store the core (contents of process' memory contents) in an external - file on disk in <filename>/var/lib/systemd/coredump</filename>.</para> + <para>By default, <command>systemd-coredump</command> will log the core dump including a backtrace + if possible to the journal and store the core dump itself in an external file in + <filename>/var/lib/systemd/coredump</filename>.</para> - <para>When the kernel invokes <command>systemd-coredump</command> to handle a coredump, + <para>When the kernel invokes <command>systemd-coredump</command> to handle a core dump, it will connect to the socket created by the <filename>systemd-coredump.socket</filename> unit, which in turn will spawn a <filename>systemd-coredump@.service</filename> instance - to process the coredump. Hence <filename>systemd-coredump.socket</filename> + to process the core dump. Hence <filename>systemd-coredump.socket</filename> and <filename>systemd-coredump@.service</filename> are helper units which do the actual - processing of coredumps and are subject to normal service management.</para> + processing of core dumps and are subject to normal service management.</para> - <para>The log entry and a backtrace are stored in the journal, and can be viewed with - <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. - <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> - may be used to list and extract coredumps or load them in - <citerefentry project='man-pages'><refentrytitle>gdb</refentrytitle><manvolnum>1</manvolnum></citerefentry>. + <para>The behavior of a specific program upon reception of a signal is governed by a few + factors which are described in detail in + <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + In particular, the core dump will only be processed when the related resource limits are sufficient. </para> + </refsect1> - <para>The coredump helper is invoked anew each time. Therefore, any configuration - changes will take effect on the invocation of <command>systemd-coredump</command>. + <refsect1> + <title>Configuration</title> + <para>For programs started by <command>systemd</command> process resource limits can be set by directive + <varname>LimitCore=</varname>, see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + + <para>In order to be used <command>systemd-coredump</command> must be configured in + <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> + parameter <varname>kernel.core_pattern</varname>. The syntax of this parameter is explained in + <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + Systemd installs the file <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> which configures + <varname>kernel.core_pattern</varname> accordingly. This file may be masked or overridden to use a different + setting following normal + <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> + rules. If the sysctl configuration is modified, it must be updated in the kernel before it takes effect, see - <citerefentry><refentrytitle>systemd-sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> + <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> and - <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>. + <citerefentry><refentrytitle>systemd-sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>. </para> + + <para>The behaviour of <command>systemd-coredump</command> itself is configured through the configuration file + <filename>/etc/systemd/coredump.conf</filename> and corresponding snippets + <filename>/etc/systemd/coredump.conf.d/*.conf</filename>, see + <citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. A new + instance of <command>systemd-coredump</command> is invoked upon receiving every core dump. Therefore, changes + in these files will take effect the next time a core dump is received.</para> + + <para>Resources used by core dump files are restricted in two ways. Parameters like maximum size of acquired + core dumps and files can be set in files <filename>/etc/systemd/coredump.conf</filename> and snippets mentioned + above. In addition the storage time of core dump files is restricted by <command>systemd-tmpfiles</command>, + corresponding settings are by default in <filename>/usr/lib/tmpfiles.d/systemd.conf</filename>.</para> + </refsect1> + + <refsect1> + <title>Usage</title> + <para>Data stored in the journal can be viewed with + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + as usual. + <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + can be used to retrieve saved core dumps independent of their location, to display information and to process + them e.g. by passing to the GNU debugger (gdb).</para> </refsect1> <refsect1> @@ -119,6 +136,7 @@ <citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-sysctl.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. |