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 @@ coredump.conf coredump.conf.d - Coredump storage configuration files + Core dump storage configuration files @@ -86,7 +86,7 @@ Controls where to store cores. One of none, external, journal, and both. When - none, the coredumps will be logged but not + none, the core dumps will be logged but not stored permanently. When external (the default), cores will be stored in /var/lib/systemd/coredump. When journal, cores will be stored in @@ -114,7 +114,7 @@ ProcessSizeMax= 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. @@ -132,14 +132,14 @@ KeepFree= Enforce limits on the disk space taken up by - externally stored coredumps. 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. 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). 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 systemd-tmpfiles8. 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 @@ coredumpctl - Retrieve coredumps from the journal + Retrieve and process saved core dumps and metadata @@ -60,9 +60,10 @@ Description - coredumpctl may be used to - retrieve coredumps from - systemd-journald8. + coredumpctl is a tool that can be used to retrieve and process core + dumps and metadata which were saved by + systemd-coredump8. + @@ -71,18 +72,23 @@ The following options are understood: + + + + - Do not print column headers. - + Do not print column headers. + + - Show information of a single coredump only, - instead of listing all known coredumps. + Show information of a single core dump only, instead of listing + all known core dumps. @@ -90,7 +96,7 @@ FIELD 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. @@ -110,11 +116,11 @@ - - - - + + + + Commands The following commands are understood: @@ -122,23 +128,31 @@ list - List coredumps captured in the journal + List core dumps captured in the journal matching specified characteristics. If no command is - specified, this is the implied default. + specified, this is the implied default. + + It's worth noting that different restrictions apply to + data saved in the journal and core dump files saved in + /var/lib/systemd/coredump, see overview in + systemd-coredump8. + 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. info - Show detailed information about coredumps + Show detailed information about core dumps captured in the journal. dump - Extract the last coredump matching specified - characteristics. The coredump will be written on standard + Extract the last core dump matching specified + characteristics. The core dump will be written on standard output, unless an output file is specified with . @@ -146,7 +160,7 @@ gdb - Invoke the GNU debugger on the last coredump + Invoke the GNU debugger on the last core dump matching specified characteristics. @@ -197,7 +211,7 @@ Exit status 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. @@ -206,13 +220,13 @@ Examples - List all the coredumps of a program named foo + List all the core dumps of a program named foo # coredumpctl list foo - Invoke gdb on the last coredump + Invoke gdb on the last core dump # coredumpctl gdb @@ -225,7 +239,7 @@ - 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> # coredumpctl -o bar.coredump dump /usr/bin/bar 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 @@ systemd-coredump systemd-coredump.socket systemd-coredump@.service - Log and store core dumps + Acquire, save and process core dumps @@ -58,59 +58,76 @@ Description + systemd-coredump is a system service that can acquire core dumps + from the kernel and handle them in various ways. - systemd-coredump 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 - kernel.core_pattern sysctl8 - setting. The syntax of this setting is explained in - core5. - Systemd installs /usr/lib/sysctl.d/50-coredump.conf which configures - kernel.core_pattern to invoke systemd-coredump. - This file may be masked or overridden to use a different setting following normal - sysctl.d5 - rules. - - The behavior of a specific program upon reception of a - signal is governed by a few factors which are described in detail - in core5. - In particular, the coredump will only be processed when the - related resource limits are high enough. For programs started by - systemd, those may be set using - LimitCore= (see - systemd.exec5). - - - The behaviour of systemd-coredump is configured through - /etc/systemd/coredump.conf and other configuration files. See - coredump.conf5 - for details. By default, systemd-coredump 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 /var/lib/systemd/coredump. - - When the kernel invokes systemd-coredump to handle a coredump, - 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 coredump. Hence systemd-coredump.socket - and systemd-coredump@.service are helper units which do the actual - processing of coredumps and are subject to normal service management. - - The log entry and a backtrace are stored in the journal, and can be viewed with - journalctl1. - coredumpctl1 - may be used to list and extract coredumps or load them in + 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 gdb1. - The coredump helper is invoked anew each time. Therefore, any configuration - changes will take effect on the invocation of systemd-coredump. + 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 + core5. + 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.exec5. + + + In order to be used systemd-coredump must be configured in + sysctl8 + parameter kernel.core_pattern. The syntax of this parameter is explained in + core5. + 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.d5 + rules. If the sysctl configuration is modified, it must be updated in the kernel before it takes effect, see - systemd-sysctl8 + sysctl8 and - sysctl8. + systemd-sysctl8. + + 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.conf5. 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 + journalctl1 + as usual. + coredumpctl1 + 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). @@ -119,6 +136,7 @@ coredump.conf5, coredumpctl1, systemd-journald.service8, + systemd-tmpfiles8, core5, sysctl.d5, systemd-sysctl.service8.