Boot to LTSP from USB pen?

[Karl Hegbloom]

On Wed, 2005-10-05 at 16:02 +0100, Eamonn Sullivan wrote:
> I'm afraid I know very little about LTSP and the docs are rather
> involved. I'm wondering if it's possible to just put some code on the
> USB pen, boot from there and get a GDM screen from the server. Is
> anyone doing anything like this? 

If the computers have PXE network boot option in BIOS setup, you can
boot to LTSP from that.  For example, on my laptop, I push F8 during
POST, and I get a menu of boot device options.  I can choose the network
card as the boot device, and it begins the PXE / DHCP boot process that
can boot the laptop as an LTSP client running an X server.

If you put a boot sector on the USB stick, by using either syslinux or
Grub, it is possible to use that to perform a network boot.  You will
need to put a kernel on it, and configure an initramfs that mounts the
root file system over NFS.  It is probably possible to have it get the
NFS server and root file system location from the DHCP server.  Look at
the klibc package as well as the initramfs-tools package to learn about
the toolset you'll have available.  The initramfs-tools already has an
NFS mounted root boot option.  I've never tried to use it.

There is also a program called etherboot that can be used from a floppy
disk or from a network card's boot ROM.  Find it via the link at the
bottom of:

 http://wiki.ltsp.org/twiki/bin/view/Ltsp/PXE

You may be able to chain-load to the etherboot image from Grub installed
on the USB stick...  I'm not sure if you'd treat it like a kernel, or if
you'd chain-load to it like it's a Windows/DOS partition.  I'm also not
sure if it would need to be the data of it's own partition, or if it can
be a file in the /boot directory of the USB stick.  If it works from
Grub, it would probably work from syslinux also, in case you want a vfat
file system on the stick for Windows compatibility.  (I'd use ext3 and
the Windows driver for that.)

-- 
Karl Hegbloom <hegbloom at pdx.edu>