I've never played with those systems, and your upgrade uption completely depends on the distro, but if you make certain partitions, it should ask you before touching them.. I think most 'upgrades' will ask you where you installed linux, where you would select the / partition....
I have a ton of partitions on my machine, even though I will never upgrade it unless a new kernal comes out lol...
/
/etc
/home
/usr