Christian

Kildau

Network Engineer


Welcome to my little blog. I am mostly techie over here, blogging about networking and system administration topics, but there will also be some Travel Reports from time to time…

How to activate Serial Console on Debian Squeeze

July 6, 2011Christian Kildau5 Comments

Activating a Serial Console starting at the bootloader all the way up to a tty login requires just a few steps, but it took me some time to figure out all the knobs. Here’s how to do it with Debian Squeeze:

To have configruation changes persistent in Debian, you may not edit /boot/grub/grub.cfg directly, but need to edit/add the appropiate lines in /etc/defaults/grub:

1
2
3
GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,9600n8"
GRUB_TERMINAL=console
GRUB_SERIAL_COMMAND="serial --speed=9600 --unit=0 --word=8 --parity=no --stop=1"

Now run update-grub and you’ll get the Bootloader and all Kernel and Init messages on your serial console the next time you boot.

To get a login promt on serial you need to modify /etc/inittab to:

1
2
3
4
5
6
7
8
1:2345:respawn:/sbin/getty 38400 tty1
2:23:respawn:/sbin/getty 38400 tty2
3:23:respawn:/sbin/getty 38400 tty3
4:23:respawn:/sbin/getty 38400 tty4
5:23:respawn:/sbin/getty 38400 tty5
6:23:respawn:/sbin/getty 38400 tty6
# Serial console
s0:2345:respawn:/sbin/getty -L 9600 ttyS0 vt102

That’s it. run init q to reload init and activate serial login, or simply reboot.

This article has 5 comments
  1. Web Hosting
    2012/03/28

    Thanks, worked perfectly on a HP ProLiant DL380G5 with an iLO 2 mgmt card. No need to buy the expensive advanced license for the iLO2 now!

  2. Maarten
    2012/04/08

    Thanks! Exactly what I was googling for.

  3. Elijah Jericjo
    2012/11/21

    Thanks for that it works well, the only thing is though it really slows the boot process down, but I can live that.

  4. Merlijn
    2013/03/19

    Thanks 🙂
    Easy and simple steps, but I do find myself googling for it every time I need to enable a serial console. This was exactly what I needed. Most console servers doe support 19200 as speed nowadays however 😉

  5. Michal Dwuznik
    2013/07/19

    Well, _most_ servers nowadays support 115200 on Serial-Over-LAN.

    Sluggishness during boot gone…


Leave a Reply