Linux maintains several system logs that help you administer a
Linux system by informing you of important events. Probably the most
important log is the file
/var/log/messages,
which records a variety of events, including system error messages,
system startups, and system shutdowns. Like most other Linux files,
the file contains ASCII text, so you can view it with a text editor or
the text processing commands described in Chapter 13.
A special command,
dmesg, makes it easy to
view the log messages related to the most recent system startup. If
your system is behaving unusually, use
dmesg to
quickly see if something went wrong during the system startup
sequence. Of course, you must have some way of determining what's
usual and unusual among the many messages emitted during system
startup. The best way to do so is to print the output of the
dmesg command and keep it on hand for comparison
with suspicious output. If your system has an attached printer, you
can print the output of
dmesg by entering the
following command:
dmesg | lpr
Other logs found in the
/var/log directory
include:
-
apache
-
A directory that contains two log files
pertaining to the Apache web server,
access.log
and
error.log.
-
exim
-
A directory that contains several log
files pertaining to the
exim mail transfer
agent.
-
nmb and smb
-
Files that contain log entries pertaining
to Samba, the Microsoft-compatible networking server.
-
ppp.log
-
A file the contains log entries
pertaining to PPP.
