diff options
| -rw-r--r-- | man/coredump.conf.xml | 16 | ||||
| -rw-r--r-- | man/coredumpctl.xml | 60 | ||||
| -rw-r--r-- | man/systemd-coredump.xml | 98 |
3 files changed, 103 insertions, 71 deletions
diff --git a/man/coredump.conf.xml b/man/coredump.conf.xml index 2064a96523..4f95680a3a 100644 --- a/man/coredump.conf.xml +++ b/man/coredump.conf.xml @@ -45,7 +45,7 @@ <refnamediv> <refname>coredump.conf</refname> <refname>coredump.conf.d</refname> - <refpurpose>Coredump storage configuration files</refpurpose> + <refpurpose>Core dump storage configuration files</refpurpose> </refnamediv> <refsynopsisdiv> @@ -86,7 +86,7 @@ <listitem><para>Controls where to store cores. One of <literal>none</literal>, <literal>external</literal>, <literal>journal</literal>, and <literal>both</literal>. When - <literal>none</literal>, the coredumps will be logged but not + <literal>none</literal>, the core dumps will be logged but not stored permanently. When <literal>external</literal> (the default), cores will be stored in <filename>/var/lib/systemd/coredump</filename>. When <literal>journal</literal>, cores will be stored in @@ -114,7 +114,7 @@ <term><varname>ProcessSizeMax=</varname></term> <listitem><para>The maximum size in bytes of a core - which will be processed. Coredumps exceeding this size + which will be processed. Core dumps exceeding this size will be logged, but the backtrace will not be generated and the core will not be stored.</para></listitem> </varlistentry> @@ -132,14 +132,14 @@ <term><varname>KeepFree=</varname></term> <listitem><para>Enforce limits on the disk space taken up by - externally stored coredumps. <option>MaxUse=</option> makes - sure that old coredumps are removed as soon as the total disk - space taken up by coredumps grows beyond this limit (defaults + externally stored core dumps. <option>MaxUse=</option> makes + sure that old core dumps are removed as soon as the total disk + space taken up by core dumps grows beyond this limit (defaults to 10% of the total disk size). <option>KeepFree=</option> controls how much disk space to keep free at least (defaults to 15% of the total disk size). Note that the disk space used - by coredumps might temporarily exceed these limits while - coredumps are processed. Note that old coredumps are also + by core dumps might temporarily exceed these limits while + core dumps are processed. Note that old core dumps are also removed based on time via <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Set either value to 0 to turn off size-based diff --git a/man/coredumpctl.xml b/man/coredumpctl.xml index 0f1afe77c3..abc245be5e 100644 --- a/man/coredumpctl.xml +++ b/man/coredumpctl.xml @@ -45,7 +45,7 @@ <refnamediv> <refname>coredumpctl</refname> - <refpurpose>Retrieve coredumps from the journal</refpurpose> + <refpurpose>Retrieve and process saved core dumps and metadata</refpurpose> </refnamediv> <refsynopsisdiv> @@ -60,9 +60,10 @@ <refsect1> <title>Description</title> - <para><command>coredumpctl</command> may be used to - retrieve coredumps from - <citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + <para><command>coredumpctl</command> is a tool that can be used to retrieve and process core + dumps and metadata which were saved by + <citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>. + </para> </refsect1> <refsect1> @@ -71,18 +72,23 @@ <para>The following options are understood:</para> <variablelist> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="version" /> + <varlistentry> <term><option>--no-legend</option></term> - <listitem><para>Do not print column headers. - </para></listitem> + <listitem><para>Do not print column headers.</para></listitem> </varlistentry> + <xi:include href="standard-options.xml" xpointer="no-pager" /> + <varlistentry> <term><option>-1</option></term> - <listitem><para>Show information of a single coredump only, - instead of listing all known coredumps. </para></listitem> + <listitem><para>Show information of a single core dump only, instead of listing + all known core dumps.</para></listitem> </varlistentry> <varlistentry> @@ -90,7 +96,7 @@ <term><option>--field=</option><replaceable>FIELD</replaceable></term> <listitem><para>Print all possible data values the specified - field takes in matching coredump entries of the + field takes in matching core dump entries of the journal.</para></listitem> </varlistentry> @@ -110,11 +116,11 @@ </para></listitem> </varlistentry> - <xi:include href="standard-options.xml" xpointer="help" /> - <xi:include href="standard-options.xml" xpointer="version" /> - <xi:include href="standard-options.xml" xpointer="no-pager" /> - </variablelist> + </refsect1> + + <refsect1> + <title>Commands</title> <para>The following commands are understood:</para> @@ -122,23 +128,31 @@ <varlistentry> <term><command>list</command></term> - <listitem><para>List coredumps captured in the journal + <listitem><para>List core dumps captured in the journal matching specified characteristics. If no command is - specified, this is the implied default.</para></listitem> + specified, this is the implied default.</para> + + <para>It's worth noting that different restrictions apply to + data saved in the journal and core dump files saved in + <filename>/var/lib/systemd/coredump</filename>, see overview in + <citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>. + Thus it may very well happen that a particular core dump is still listed + in the journal while its corresponding core dump file has already been + removed.</para></listitem> </varlistentry> <varlistentry> <term><command>info</command></term> - <listitem><para>Show detailed information about coredumps + <listitem><para>Show detailed information about core dumps captured in the journal.</para></listitem> </varlistentry> <varlistentry> <term><command>dump</command></term> - <listitem><para>Extract the last coredump matching specified - characteristics. The coredump will be written on standard + <listitem><para>Extract the last core dump matching specified + characteristics. The core dump will be written on standard output, unless an output file is specified with <option>--output=</option>. </para></listitem> </varlistentry> @@ -146,7 +160,7 @@ <varlistentry> <term><command>gdb</command></term> - <listitem><para>Invoke the GNU debugger on the last coredump + <listitem><para>Invoke the GNU debugger on the last core dump matching specified characteristics. </para></listitem> </varlistentry> @@ -197,7 +211,7 @@ <refsect1> <title>Exit status</title> <para>On success, 0 is returned; otherwise, a non-zero failure - code is returned. Not finding any matching coredumps is treated as + code is returned. Not finding any matching core dumps is treated as failure. </para> </refsect1> @@ -206,13 +220,13 @@ <title>Examples</title> <example> - <title>List all the coredumps of a program named foo</title> + <title>List all the core dumps of a program named foo</title> <programlisting># coredumpctl list foo</programlisting> </example> <example> - <title>Invoke gdb on the last coredump</title> + <title>Invoke gdb on the last core dump</title> <programlisting># coredumpctl gdb</programlisting> </example> @@ -225,7 +239,7 @@ </example> <example> - <title>Extract the last coredump of /usr/bin/bar to a file named + <title>Extract the last core dump of /usr/bin/bar to a file named <filename noindex="true">bar.coredump</filename></title> <programlisting># coredumpctl -o bar.coredump dump /usr/bin/bar</programlisting> 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>. |