Booting from a USB drive

Bratmon · 12-24-2009, 07:58 AM

Hello,

I believe I successfully installed Debian onto my external hard drive, but when I try to boot to it from grub I get "unrecognized device string". My HD install of Ubuntu works correctly. From a running system I get:

Code:

grub> root (hd
 Possible disks are:  hd0 hd1

But from the grub command line I get:

Code:

grub> root (hd
Possible disks are:  hd0

So I believe I need to get grub to see the drive somehow.
Attached is the menu.lst (create by Ubuntu.)

Thanks,
Bratmon

minrich · 12-24-2009, 08:25 AM

Assuming your external hard drive is connected by usb, and assuming your bios allows for booting from usb, and assuming you have set up your computer to boot from usb, and assuming that both your ubuntu 9.10 and debian external hard drive are formatted as ext3, I think that 9.10 defaults to ext4 and to GRUB2 (looking at your file.txt/menu.lst attachment this is plain GRUB, but it has no menu entry for your external drive which would be sda or sbd).

What I would suggest is that you boot into ubuntu and attach the external harddrive and find out what UUID it has.

run:

ls /dev/disk/by-uuid

do this before and after attaching the external hard drive to find out which uuid applies.

If I recall correctly,ubuntu 9.10 doesn't see devices as hd* and sd* anymore, hence the need to address it by its univeral id

Hope this helps

Bratmon · 12-24-2009, 09:20 PM

The thing is, my BIOS doesn't support booting from USB. I'm looking for a way around that.

cola · 12-24-2009, 11:31 PM

Quote:

Originally Posted by Bratmon

Hello,

I believe I successfully installed Debian onto my external hard drive, but when I try to boot to it from grub I get "unrecognized device string". My HD install of Ubuntu works correctly. From a running system I get:

Code:

grub> root (hd
 Possible disks are:  hd0 hd1

But from the grub command line I get:

Code:

grub> root (hd
Possible disks are:  hd0

So I believe I need to get grub to see the drive somehow.
Attached is the menu.lst (create by Ubuntu.)

Thanks,
Bratmon

Look at the lines for Debian.

Code:

title Debian
root (hd1,1)
kernel /boot/initrd.img-2.6.26-2-686
initrd /boot/vmlinuz-2.6.26-2-686

Code:

title Debian
root (hd1,1)
kernel /boot/vmlinuz-2.6.26-2-686
initrd /boot/initrd.img-2.6.26-2-686

michaelk · 12-25-2009, 10:36 AM

grub relies on the BIOS for drive detection but since your BIOS can not boot from USB you will need to use another boot manager. Check out PLoP.
http://www.plop.at/en/bootmanager.html