ubuntu on external USB harddrive
Published on June 17, 2009 By werewolf In Personal Computing

Hi all,

I have Vista installed to boot on my C: drive.  I installed Ubuntu on my external USB harddrive and as long as the external is on, my GRUB loader comes up correctly.

The thing is that I don't want to leave my USB drive turned on all the time.  I would like to be able to turn it off, but still get the boot loader.  I get "Error 21" if the drive is turned off.

I believe that the loader is actually on the USB drive.  I have not figured out how to move it to the Vista boot partition.  This is a Dell machine, so there is that little hidden partition to deal with, but I believe that the boot part is HD0,2

I have the following in my menu.lst:

## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

.....i deleted lines for brevity .....
##      kopt_2_6_8=root=/dev/hdc1 ro
##      kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=/dev/sdc5 ro <--------------------------------- I added this line

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd2,4) <--------------------------------- I added this line. this is where ubuntu is installed

This is the Vista load entry:

# This entry automatically added by the Debian installer for a non-linux OS
# on /dev/sda3
title        Windows Vista (loader)
rootnoverify    (hd0,2)
chainloader    +1

I guess I have to figure out how to move the grub to hd0,2

Anyone have any ideas?




on Jun 17, 2009

I had the same issue, but I cannot remember what I did to fix it.  Try searching the Ubuntu Forums, I think thats  where I found the fix for this.  If I find it i will post it here for you but you might want to yourself because I'm in the middle of taking my finals.  But If i remember you have to have the boot loader moved to the boot drive... (usually where ever C is located)... 

The reason why I don't remember the fix is because I recently reinstalled Windows and  Ubuntu and set aside a 25GB partition for it and dual booted that way...

on Jun 17, 2009

Okay...back to the forums...thanks and GOOD LUCK on the finals

and just to be clear, I think I need to move the grub from the USB drive to the Vista drive.  Not just install a new grub on the Vista.

on Jun 18, 2009

That's why I don't use boot managers anymore.

Now, if I install another OS to a separate drive, I disconnect any other drive with an OS installed on it first.

Then all I have to do is change the boot order in the BIOS to choose which one I boot to.