Making sure to partition the right disk(s)

Hello all.

It's not too unusual that sometimes disks get recognized in a different 
order across reboots.
How can I make sure I'm repartitioning the right disk and not another 
one containing data? I can't find any way to bind some info about HDD to 
"disk1" instead of "disk2".

If it's not currently supported, it shouldn't be too hard to add to 
20-hwdetect.sh (I can do it and share the result, if someone is 
interested). But if it's already supported, better to use the official 
method. :)

-- 
Diego Zuccato
DIFA - Dip. di Fisica e Astronomia
Servizi Informatici
Alma Mater Studiorum - Università di Bologna
V.le Berti-Pichat 6/2 - 40127 Bologna - Italy
tel.: +39 051 20 95786