IPMI

Start IPMI shell;

# ipmitool -I lanplus -H 1.2.3.4 -U ADMIN shell

Use ipmitool to for serial over lan to host;

# ipmitool -I lanplus -H 1.2.3.4 -U ADMIN sol activate

Configure GRUB to work with Serial Device;

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
#          initrd /initrd-version.img
#boot=/dev/sda

# Redirect grub output to serial console, which is on COM Port 2
serial --unit=1 --speed=19200 --word=8 --parity=no --stop=1   
terminal --timeout=10 serial console

default=0
timeout=10

# making IPMI friendly
#splashimage=(hd0,0)/grub/splash.xpm.gz
#hiddenmenu

title CentOS (2.6.18-92.1.22.el5)
	root (hd0,0)
	kernel /vmlinuz-2.6.18-92.1.22.el5 ro root=/dev/VolGroup00/LogVol00 console=ttyS1,19200n8 console=tty0
	initrd /initrd-2.6.18-92.1.22.el5.img
title CentOS (2.6.18-92.el5)
	root (hd0,0)
	kernel /vmlinuz-2.6.18-92.el5 ro root=/dev/VolGroup00/LogVol00 console=tty0 console=ttyS1,19200n8
	initrd /initrd-2.6.18-92.el5.img
title "My bios update"
	kernel /memdisk
	initrd /fwdisk.img floppy