Serial Console HowTo
Overview
Sometimes it is handy to be able to redirect a TTY Console to a serial port. One such example might be that your server is headless (No VGA, Keyboard, or Monitor) The info on this page will help you enable console access via a serial port.
Instructions
To redirect a Linux Console to a serial port edit /etc/inittab and add this line at the end of the '# Run gettys in standard runlevels' section.
S0:2345:respawn /usr/sbin/agetty -h ttyS0 38400 vt100
When done issue this command to make the changes take effect:
init q
Explanation
TTY-ID:RUN-LEVELS:respawn COMMAND -SWITCHES PORT TERMINAL-EMULATION (For greater detail on inittab or agetty see the References Section below)
General Notes
1) There will most likely already be a 6:12345, if that is the case comment out the old 6:12345 with a # like this #6:12345.
2) In this HowTo I used 'agetty' but there are other getty packages such as 'getty', 'mgetty', and 'mingetty' use whichever is the default on your distribution. If you use one of the other getty packages keep in mind that the syntax will most likely be different.
3) ttyS0 = COM1, ttyS1 = COM2 etc...
References
Linux Serial Console HowTo
Linux Journal - Serial as a Console
inittab Man Pages
agetty Man Pages