systemd-coredump, systemd-coredump.socket, systemd-coredump@.service - Acquire, save and process core dumps
/lib/systemd/systemd-coredump systemd-coredump@.service systemd-coredump.socket
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.
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 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.
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).
coredump.conf(5), coredumpctl(1), systemd-journald.service(8), systemd- tmpfiles(8), core(5), sysctl.d(5), systemd-sysctl.service(8).
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.