compacting an Ubuntu partition

[compdoc]

>Do you mean I should reduce the partition from 80 to 60, then
>from 60 to 40, then from 20 to 20 then from 20 to 10, rather
>than just reducing it in one step?

I don't think that's necessary. If you move and resize, it can take a while, 
but if you just resize it's not too bad. With Windows drives I think it's a 
good idea to defrag first.

But no matter how you do this, it's a risk. So, make sure you have a working 
backup of the drive. Clonezilla is great for that.