NAME¶
systemd-coredump, systemd-coredump.socket, systemd-coredump@.service - Acquire,
save and process core dumps
SYNOPSIS¶
/lib/systemd/systemd-coredump
systemd-coredump@.service
systemd-coredump.socket
DESCRIPTION¶
systemd-coredump is a system service that can acquire core dumps from the
kernel and handle them in various ways.
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.
When the kernel invokes
systemd-coredump to handle a core dump, it will
connect to the socket created by the systemd-coredump.socket unit, which in
turn will spawn a 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.
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.
CONFIGURATION¶
For programs started by
systemd process resource limits can be set by
directive
LimitCore=, see
systemd.exec(5).
In order to be used
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).
The behaviour 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.
USAGE¶
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¶
coredump.conf(5),
coredumpctl(1),
systemd-journald.service(8),
systemd-tmpfiles(8),
core(5),
sysctl.d(5),
systemd-sysctl.service(8).