coredump.conf, coredump.conf.d — Core dump storage configuration files
/etc/systemd/coredump.conf
/etc/systemd/coredump.conf.d/*.conf
/run/systemd/coredump.conf.d/*.conf
/usr/lib/systemd/coredump.conf.d/*.conf
These files configure the behavior of
systemd-coredump(8),
a handler for core dumps invoked by the kernel. Whether systemd-coredump is used
is determined by the kernel's
kernel.core_pattern sysctl(8)
setting. See
systemd-coredump(8)
and
core(5)
pages for the details.
The default configuration is set during compilation, so configuration is only needed when it is
necessary to deviate from those defaults. The main configuration file is either in
/usr/lib/systemd/ or /etc/systemd/ and contains commented out
entries showing the defaults as a guide to the administrator. Local overrides can be created by creating
drop-ins, as described below. The main configuration file can also be edited for this purpose (or a copy
in /etc/ if it's shipped in /usr/) however using drop-ins for
local configuration is recommended over modifications to the main configuration file.
In addition to the "main" configuration file, drop-in configuration snippets are read from
/usr/lib/systemd/*.conf.d/, /usr/local/lib/systemd/*.conf.d/,
and /etc/systemd/*.conf.d/. Those drop-ins have higher precedence and override the
main configuration file. Files in the *.conf.d/ configuration subdirectories are
sorted by their filename in lexicographic order, regardless of in which of the subdirectories they
reside. When multiple files specify the same option, for options which accept just a single value, the
entry in the file sorted last takes precedence, and for options which accept a list of values, entries
are collected as they occur in the sorted files.
When packages need to customize the configuration, they can install drop-ins under
/usr/. Files in /etc/ are reserved for the local administrator,
who may use this logic to override the configuration files installed by vendor packages. Drop-ins have to
be used to override package drop-ins, since the main configuration file has lower precedence. It is
recommended to prefix all filenames in those subdirectories with a two-digit number and a dash, to
simplify the ordering of the files. This also defined a concept of drop-in priority to allow
distributions to ship drop-ins within a specific range lower than the range used by users. This should
lower the risk of package drop-ins overriding accidentally drop-ins defined by users.
To disable a configuration file supplied by the vendor, the recommended way is to place a symlink
to /dev/null in the configuration directory in /etc/, with the
same filename as the vendor configuration file.
All options are configured in the [Coredump] section:
Storage=¶Controls where to store cores. One of "none",
"external", and "journal". When "none", the core
dumps may be logged (including the backtrace if possible), but not stored permanently. When
"external" (the default), cores will be stored in
/var/lib/systemd/coredump/. When "journal", cores will be
stored in the journal and rotated following normal journal rotation patterns.
When cores are stored in the journal, they might be compressed following journal compression settings, see journald.conf(5). When cores are stored externally, they will be compressed by default, see below.
Note that in order to process a coredump (i.e. extract a stack trace) the core must be written
to disk first. Thus, unless ProcessSizeMax= is set to 0 (see below), the core will
be written to /var/lib/systemd/coredump/ either way (under a temporary filename,
or even in an unlinked file), Storage= thus only controls whether to leave it
there even after it was processed.
Compress=¶Controls compression for external
storage. Takes a boolean argument, which defaults to
"yes".
ProcessSizeMax=¶The maximum size in bytes of a core which will be processed. Core dumps exceeding this size may be stored, but the stack trace will not be generated. Like other sizes in this same config file, the usual suffixes to the base of 1024 are allowed (B, K, M, G, T, P, and E). Defaults to 1G on 32-bit systems, 32G on 64-bit systems.
Setting Storage=none and ProcessSizeMax=0
disables all coredump handling except for a log entry.
ExternalSizeMax=, JournalSizeMax=¶The maximum (compressed or uncompressed) size in bytes of a coredump to be saved in
separate files on disk (default: 1G on 32-bit systems, 32G on 64-bit systems) or in the journal
(default: 767M). Note that the journal service enforces a hard limit on journal log records of 767M,
and will ignore larger submitted log records. Hence, JournalSizeMax= may be
lowered relative to the default, but not increased. Unit suffixes are allowed just as in
ProcessSizeMax=.
ExternalSizeMax=infinity sets the core size to unlimited.
MaxUse=, KeepFree=¶Enforce limits on the disk space, specified
in bytes, taken up by externally stored core dumps.
Unit suffixes are allowed just as in ProcessSizeMax=.
MaxUse= 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). KeepFree=
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 core dumps might temporarily exceed these limits while
core dumps are processed. Note that old core dumps are also
removed based on time via
systemd-tmpfiles(8).
Set either value to 0 to turn off size-based cleanup.
The defaults for all values are listed as comments in the
template /etc/systemd/coredump.conf file that
is installed by default.