“…people like me are fortunate that Linux comes with lots of great tools for recording and storing information about system operations on an ongoing basis. This is accomplished via the syslog facility, a central system message logging facility standard on all modern Unix systems.”
“Under Linux, this subsystem consists of a number of components: two daemons, a configuration file, and a number of log files that will record the actual data. The daemons are called syslogd and klogd, and they are usually started automatically when the system boots. (The file that actually does the work is typically /etc/rc.d/init. d/syslog, executed via a link to a file in one of the rcn.d subdirectories.)”
“The syslog facility collects all of the system messages produced by all of the various subsystems running on Linux and either records them or forwards them to some responsible party as specified by its configuration file. Most messages tend to be written to a log file, and the conventional location for these log files is /var/log.”