Users Guide

Configuring Linux for serial console during boot in
RHEL 6
The following steps are specific to the Linux GRand Unified Bootloader (GRUB). Similar changes are required if a different boot
loader is used.
NOTE: When you configure the client VT100 emulation window, set the window or application that is displaying the
redirected Virtual Console to 25 rows x 80 columns to make sure the correct text displays. Else, some text screens may be
garbled.
Edit the /etc/grub.conf file as follows:
1. Locate the General Setting sections in the file and add the following:
serial --unit=1 --speed=57600 terminal --timeout=10 serial
2. Append two options to the kernel line:
kernel ............. console=ttyS1,115200n8r console=tty1
3. Disable GRUB's graphical interface and use the text-based interface. Else, the GRUB screen is not displayed in RAC Virtual
Console. To disable the graphical interface, comment-out the line starting with splashimage.
The following example provides a sample /etc/grub.conf file that shows the changes described in this procedure.
# grub.conf generated by anaconda
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that all
# kernel and initrd paths are relative to /, e.g.
# root (hd0,0)
# kernel /boot/vmlinuz-version ro root=/dev/sdal
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=0
timeout=10
#splashimage=(hd0,2)/grub/splash.xpm.gz
serial --unit=1 --speed=57600
terminal --timeout=10 serial
title Red Hat Linux Advanced Server (2.4.9-e.3smp) root (hd0,0)
kernel /boot/vmlinuz-2.4.9-e.3smp ro root=/dev/sda1 hda=ide-scsi console=ttyS0
console=ttyS1,115200n8r
initrd /boot/initrd-2.4.9-e.3smp.img
title Red Hat Linux Advanced Server-up (2.4.9-e.3) root (hd0,00)
kernel /boot/vmlinuz-2.4.9-e.3 ro root=/dev/sda1 s
initrd /boot/initrd-2.4.9-e.3.im
4. To enable multiple GRUB options to start Virtual Console sessions through the RAC serial connection, add the following line
to all options:
console=ttyS1,115200n8r console=tty1
The example shows console=ttyS1,57600 added to the first option.
NOTE:
If the boot loader or operating system provides serial redirection such as GRUB or Linux, then the BIOS
Redirection After Boot setting must be disabled. This is to avoid potential race condition of multiple components
accessing the serial port.
Enabling login to the virtual console after boot
In the file /etc/inittab, add a new line to configure agetty on the COM2 serial port:
Setting up iDRAC communication
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