systemd-coredump(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION | USAGE | SEE ALSO | NOTES | COLOPHON

SYSTEMD-COREDUMP(8)         systemd-coredump         SYSTEMD-COREDUMP(8)

NAME         top

       systemd-coredump, systemd-coredump.socket, systemd-
       coredump@.service - Acquire, save and process core dumps

SYNOPSIS         top

       /usr/lib/systemd/systemd-coredump

       /usr/lib/systemd/systemd-coredump --backtrace

       systemd-coredump@.service

       systemd-coredump.socket

DESCRIPTION         top

       systemd-coredump@.service is a system service that can acquire
       core dumps from the kernel and handle them in various ways. The
       systemd-coredump executable does the actual work. It is invoked
       twice: once as the handler by the kernel, and the second time in
       the systemd-coredump@.service to actually write the data to the
       journal.

       When the kernel invokes systemd-coredump to handle a core dump,
       it runs in privileged mode, and will connect to the socket
       created by the systemd-coredump.socket unit, which in turn will
       spawn an unprivileged systemd-coredump@.service instance to
       process the core dump. Hence systemd-coredump.socket and
       systemd-coredump@.service are helper units which do the actual
       processing of core dumps and are subject to normal service
       management.

       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 gdb(1).

       By default, systemd-coredump will log the core dump including a
       backtrace if possible to the journal and store the core dump
       itself in an external file in /var/lib/systemd/coredump.

       The behavior of a specific program upon reception of a signal is
       governed by a few factors which are described in detail in
       core(5). In particular, the core dump will only be processed when
       the related resource limits are sufficient.

       It is also possible to invoke systemd-coredump with --backtrace
       option. In this case, systemd-coredump expects a journal entry in
       the journal Journal Export Format[1] on standard input. The entry
       should contain a MESSAGE= field and any additional metadata
       fields the caller deems reasonable.  systemd-coredump will append
       additional metadata fields in the same way it does for core dumps
       received from the kernel. In this mode, no core dump is stored in
       the journal.

CONFIGURATION         top

       For programs started by systemd, process resource limits can be
       set by directive LimitCORE=, see systemd.exec(5).

       In order to be used by the kernel to handle core dumps,
       systemd-coredump must be configured in sysctl(8) parameter
       kernel.core_pattern. The syntax of this parameter is explained in
       core(5). systemd installs the file
       /usr/lib/sysctl.d/50-coredump.conf which configures
       kernel.core_pattern accordingly. This file may be masked or
       overridden to use a different setting following normal
       sysctl.d(5) rules. If the sysctl configuration is modified, it
       must be updated in the kernel before it takes effect, see
       sysctl(8) and systemd-sysctl(8).

       In order to be used in the --backtrace mode, an appropriate
       backtrace handler must be installed on the sender side. For
       example, in case of python(1), this means a sys.excepthook must
       be installed, see systemd-coredump-python[2].

       The behavior of systemd-coredump itself is configured through the
       configuration file /etc/systemd/coredump.conf and corresponding
       snippets /etc/systemd/coredump.conf.d/*.conf, see
       coredump.conf(5). A new instance of systemd-coredump is invoked
       upon receiving every core dump. Therefore, changes in these files
       will take effect the next time a core dump is received.

       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 /etc/systemd/coredump.conf and snippets mentioned
       above. In addition the storage time of core dump files is
       restricted by systemd-tmpfiles, corresponding settings are by
       default in /usr/lib/tmpfiles.d/systemd.conf.

   Disabling coredump processing
       To disable potentially resource-intensive processing by
       systemd-coredump, set

           Storage=none
           ProcessSizeMax=0

       in coredump.conf(5).

USAGE         top

       Data stored in the journal can be viewed with journalctl(1) as
       usual.  coredumpctl(1) 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).

SEE ALSO         top

       coredump.conf(5), coredumpctl(1), systemd-journald.service(8),
       systemd-tmpfiles(8), core(5), sysctl.d(5),
       systemd-sysctl.service(8).

NOTES         top

        1. Journal Export Format
           https://www.freedesktop.org/wiki/Software/systemd/export

        2. systemd-coredump-python
           https://github.com/keszybz/systemd-coredump-python

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-12-18.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2020-12-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 247                                          SYSTEMD-COREDUMP(8)

Pages that refer to this page: coredumpctl(1)core(5)coredump.conf(5)systemd.directives(7)systemd.index(7)systemd-journald.service(8)