Q. where are the log files are located under redhat or Debian or Cento OS Linux server? How do I open or view log files?
Almost all log files are located under /var/log directory (and subdirectory). You can change to this directory using cd command. You can use less, more, cat or tail command to see the logs. To Go to /var/logs directory:
# cd /var/log/
# ls
To View common log file /var/log/messages using any one of the following command:
# tail -f /var/log/messages, used in real time, it will show last 10 logs
# less /var/log/messages
# more /var/log/messages, we can see page page, press Tab to toggle between pages.
# vi /var/log/messages , to see in vi editor
# cat /var/log/messages
Q. what is the use of log messages?
- logs are used to see the status of your system. which provides the error messages and services return messages
- with the help of logs we can trouble shoot the system erors
Linux Log files and usage
/var/log/dmesg --> used for kernel boot messages
/var/log/messages --> stores the standard system error messages
/var/log/maillog --> mail system messages
/var/log/secure --> security , authentication messages
/var/log/audit/audit.log --> kernel auditing messages
var/log/debug -->Debugging log messages
/var/log/faillog --> User failed login log file
/var/log/kern.log --> Kernel log file
/var/log/lpr.log -->Printer log file
/var/log/mail.* : All mail server message log files
/var/log/mysql.* : MySQL server log file
/var/log/user.log : All userlevel logs
/var/log/xorg.0.log : X.org log file
/var/log/apache2/* : Apache web server log files directory
/var/log/lighttpd/* : Lighttpd web server log files directory
/var/log/fsck/* : fsck command log
/var/log/apport.log : Application crash report
