Ubuntu 8.04

[Karl Larsen]

Derek Broughton wrote:
> Karl Larsen wrote:
>
>   
>> Rob wrote:
>>     
>>> Several days ago, I installed Ubuntu 8.04 to an external drive here (a
>>> Hitachi 300 gig which has an option of a SATA connection or USB -- I'm
>>> using USB).  Following the installation and reboot (it did NOT ask me
>>> where -- or even if -- I wanted to install Grub) I am confronted with a
>>> Grub error nbr 21.  Unfortunately, the boot process gets no further.  I
>>> do not know how to fix this unless it's editing Grub but I have no idea
>>> where the installation tried to put Grub.  I'm guessing on my internal
>>> hard drive and not very successfully.
>>>
>>>       
>>     I think you should just forget trying to put Ubuntu on a USB
>> connected hard drive. I say this because I KNOW that the USB drive is
>> not active until AFTER Grub loads the kernel,
>>     
>
> What you KNOW is, as so often, completely wrong.  
>
>   
>> and it can't get to the 
>> kernel until the USB drive is active. It is a catch 22 problem and you
>> will never be able to fix it.
>>     
>
> Sure he will.  Two short lines to come, after I finish explaining why you
> don't have a clue what you're talking about.
>
> Modern systems not only can recognize a USB drive in grub - they can
> recognize it in the BIOS.
    My 2 year old motherboard will not recognize it. It has zero ability 
to mount a USB devise.



>   Try sticking any old USB stick in the system,
> setting the USB boot priority ahead of the hard drive in the BIOS, and
> boot.  The machine will hang because it can't find a boot block on the
> USB - because it is already reading it!  As long as the USB drive has a
> boot sector, grub can read it.  Whether grub can then _boot_ from it
> depends on "usbstorage" and probably some other modules being available in
> the initrd.  afaik, that's actually default these days - at least when I
> did the impossible and created an external USB boot drive, I didn't have to
> fiddle with the initrd.
>
> Now, to fix your USB boot problem.
>
> 1) Boot a live CD
> 2) Open a terminal session 
> 3) Plug in the USB drive
> 4) If the USB drive doesn't mount automatically:
>     sudo mount /dev/xxxx  /mnt
>    where 'xxxx' is the device name assigned to your drive's linux partition
> 5) sudo grub-install --root-directory=MOUNTPOINT DEVICE
>    where MOUNTPOINT is /mnt or /media/... (wherever it got automounted) and 
>    DEVICE is the /dev name of the device, not the partition (eg, /dev/sdb 
>    where the linux partition is /dev/sdb1)
>   
    I do the same thing using the grub system. It works fine and this 
should make it boot IF you can get BIOS to look at the right place. As I 
say my BIOS and I expect thousands of Ubuntu users do not have a 
motherboard that will boot a USB port.

Karl

> 6) reboot with your USB drive
>
>
>   


-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.
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