man/systemd-coredump.xml

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  23
  24 <refentry id="systemd-coredump" conditional='ENABLE_COREDUMP'
  25           xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27   <refentryinfo>
  28     <title>systemd-coredump</title>
  29     <productname>systemd</productname>
  30
  31     <authorgroup>
  32       <author>
  33         <contrib>Developer</contrib>
  34         <firstname>Lennart</firstname>
  35         <surname>Poettering</surname>
  36         <email>lennart@poettering.net</email>
  37       </author>
  38     </authorgroup>
  39   </refentryinfo>
  40
  41   <refmeta>
  42     <refentrytitle>systemd-coredump</refentrytitle>
  43     <manvolnum>8</manvolnum>
  44   </refmeta>
  45
  46   <refnamediv>
  47     <refname>systemd-coredump</refname>
  48     <refpurpose>Log and store core dumps</refpurpose>
  49   </refnamediv>
  50
  51   <refsynopsisdiv>
  52     <para><filename>/usr/lib/systemd/systemd-coredump</filename></para>
  53   </refsynopsisdiv>
  54
  55   <refsect1>
  56     <title>Description</title>
  57
  58     <para><command>systemd-coredump</command> can be used as a helper
  59     binary by the kernel when a user space program receives a fatal
  60     signal and dumps core. For it to be used in this capacity, it must
  61     be specified by the
  62     <varname>kernel.core_pattern</varname> <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  63     setting. The syntax of this setting is explained in
  64     <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
  65     Systemd installs <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> which configures
  66     <varname>kernel.core_pattern</varname> to invoke <command>systemd-coredump</command>.
  67     This file may be masked or overridden to use a different setting following normal
  68     <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  69     rules.</para>
  70
  71     <para>The behavior of a specific program upon reception of a
  72     signal is governed by a few factors which are described in detail
  73     in <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
  74     In particular, the coredump will only be processed when the
  75     related resource limits are high enough. For programs started by
  76     <command>systemd</command>, those may be set using
  77     <varname>LimitCore=</varname> (see
  78     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
  79     </para>
  80
  81     <para>The behaviour of <command>systemd-coredump</command> is configured through
  82     <filename>/etc/systemd/coredump.conf</filename> and other configuration files. See
  83     <citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  84     for details. By default, <command>systemd-coredump</command> will log the coredump including a
  85     backtrace if possible, and store the core (contents of process' memory contents) in an external
  86     file on disk in <filename>/var/lib/systemd/coredump</filename>.</para>
  87
  88     <para>The log entry and a backtrace are stored in the journal, and can be viewed with
  89     <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
  90     <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  91     may be used to list and extract coredumps or load them in
  92     <citerefentry project='man-pages'><refentrytitle>gdb</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
  93     </para>
  94
  95     <para>The coredump helper is invoked anew each time. Therefore, any configuration
  96     changes will take effect on the invocation of <command>systemd-coredump</command>.
  97     If the sysctl configuration is modified, it must be updated in the kernel before
  98     it takes effect, see
  99     <citerefentry><refentrytitle>systemd-sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 100     and
 101     <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 102     </para>
 103   </refsect1>
 104
 105   <refsect1>
 106     <title>See Also</title>
 107     <para>
 108       <citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 109       <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 110       <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 111       <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 112       <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 113       <citerefentry><refentrytitle>systemd-sysctl.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 114     </para>
 115   </refsect1>
 116 </refentry>