A curse on LABEL=

[Timothy Murphy]

Bryan O'Sullivan wrote:

>> How exactly would adding a new DVD drive stop the computer booting?
> 
> You open your computer.  You pop the DVD drive in.  Cables don't reach,
> so you move some around.  Your boot drive now has a different device
> number under Linux which, if you're not using something like LABEL in
> /etc/fstab, will render your machine unable to boot.

I find this scenario slightly bizarre.
First of all, I wouldn't expect my computer to boot at all
if I changed the disk controllers around,
whether I was using LABELs or not.
(I would start by using tomsrtbt or Knoppix
to see where the machine thought the disks were.)
I'm not sure what would happen on my rather ancient machine
if I moved the cables so my DVD was /dev/hda.
And my computer at least will only boot from /dev/hda or /dev/hdb,
so the changes I could make are rather limited.

As this probably makes clear, I am no computer guru.
But I've read dozens of queries over the years
from people who have been caught out by LABELs,
while I don't recall anyone complaining that they changed round
the controller connections inside the computer
and this caused the machine to cease to boot.
Wouldn't it immediately occur to anyone sufficiently au fait
with the inside of a computer to change the connections around
that they would have to consider their setup rather carefully?
Eg I imagine this would cause chaos on most Windows systems,
if C: suddenly became E: or whatever.

I honestly expected to be shown simple, likely to occur, scenarios
where LABELs are helpful,
but all the examples that have been suggested
are ones I cannot imagine a non-guru like me ever encountering.


-- 
Timothy Murphy  
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland