Bug 445650

Description of problem:

This one is interesting one :)

I was testing GUI friendlyness of Preupgrade so 
I installed FC8 on external USB connected HD took
the drive and plugged it to my mothers desktop machine and booted
of the drive and then I did let her go through the "preupgrade" phaze.

The everything went fine until it came to upgrade to rawhide.
Since this was an usb connected hd boots as sdb but when 
you choose upgrade to rawhide the drive gets remapped as sdc so
the path to the stage2.img is not sdb but sdc.

Somewhere along the line changing the grub entry to point to sdc instead of sdb
stop working as in when I tested this with my mother while ago and simple change
sdb to sdc anaconda could load and continue but now when I tried it again I just
get dropped to tui that wants me to select the correct path/partition/drive
which btw does not work.

Prepugrade gui run from gnome gets A+ from my mother
but D- when it comes to continue as in when you proceed ( upgrade to rawhide )
My mother expected that this should happen automaticly when she choose 
upgrade to rawhide and she totally got lost when she was in anaconda.
( Yes I know with ALL those options presented to her but then again she's old
not that familiar with computers and has little to no English understanding. ) 

A check needs to be added that goes something like this

Am I performing an upgrade on external connected drive. if so 
add the next partition letter for the stage2.img in grub ( sdb becomes sdc )
if not use current.

Version-Release number of selected component (if applicable):


How reproducible:

Always.

Steps to Reproduce:
1.Run preugrade on external connected hd
2.
3.
  
Actual results:


Expected results:


Additional info:


Marlboro: My old man told me, before he left this shitty world, never chase
buses or women, you'll always be left behind. 

Guard: [Harley and Marlboro are robbing an armoured car] Who are you guys?
Marlboro: Well, he's Harley Davidson, and I'm the Marlboro Man.
Guard: You look like a bunch of two-bit hoods to me.
Harley Davidson: [the car's trunk explodes] Now does that look like the work of
two-bit hoods?
Guard: Yeah. Pros would've used my keys.
[Harley and Marlboro look at each other]
Harley Davidson: Well, he likes to blow things up.