[NTLUG:Discuss] GRUB and USB drives.

[Leroy Tennison]

Daniel Hauck wrote:
> Simple: pull the hard drive.
> 
> Steve Baker wrote:
>> I have an HP laptop with WinXP - and I'm not supposed to 'mess it up' by 
>> installing Linux onto it - but I have a 300Gb USB drive, so I'd like to
>> boot Linux from that instead.
>>
>> The BIOS lets me hold down the ESC key during startup - and to select
>> "boot from USB"...so this sounds do-able.
>>
>> I installed SuSE 10.2 on the USB drive - but GRUB tried to write to the
>> laptop's internal drive instead...and that's a "No No".
>>
>> I can't figure out what to tell GRUB to make it install a boot loader
>> onto the USB drive that'll boot from the USB drive.  I can boot from a 
>> SuSE Live-CD and run grub - but I can't figure out what to tell it.
>>
>> The USB drive mounts as /dev/sda1  (system partition) and /dev/sda3
>> (user partition).  Both are formatted 'Linux Native'.  The "must not 
>> touch" hard drive is /dev/hda
>>
>> Help!  Thanks!
>>
>>
>>
>>
>>
>> _______________________________________________
>> http://www.ntlug.org/mailman/listinfo/discuss
>>
> 
> 
> _______________________________________________
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> 

This is really a two-part question: the first is how to get grub to 
install the boot loader on the  USB drive and the second is how to get 
it activated at boot time.

Concerning "part one", have you tried grub-install?  If that's not 
available then, during the SuSE install (I'm looking at 10.1 but suspect 
10.2 isn't too different) on the Installation Settings screen you can 
click Change, select Partitioning, select Create Custom Partition Setup 
and tell SuSE which partition to install on.  From the Expert tab on 
this screen you should be able to select Booting then the Boot Loader 
Installation tab to tell grub where to install.  You might be able to 
get here by launching the SuSE 10 install and selecting Upgrade but I 
haven't tried it.

Now, concerning how to get grub to be activated:

If the BIOS does what it claims, just do it.  It will be far easier and 
keep the Winders drive far more "pure".  Other BIOS tricks (if 
supported) are to change the boot drive order - if you do this you may 
also have to mark the USB drive partition as Active as well.

Another idea:

Unless it's Vista, Windows uses a hidden file at root called boot.ini.

Try the instructions at 
http://www.pmg.lcs.mit.edu/~chandra/install/install_dualboot.html and 
see if they work for you (I took about five minutes and tried it on a 
system I had and it worked - too easy).  From this reference basically you:

plug in your usb drive (once it has grub installed on it)
boot to Linux with a live CD
'dd' the boot sector to a floppy
reboot to Windows
copy the boot sector to the root of C:
At a command prompt change to C:\ and do either 'notepad boot.ini' or 
'edit boot.ini'.  Add a line at the bottom: C:\<name of boot sector 
file>="<Whatever label you want to associate with it>"

If it's Vista then you will have to do the Web research and let us know 
what you find...