GPL software is partimage.....available on most live cds such as kanotix, knoppix or mepis.
http://www.partimage.org/Main_Page
(2) if you compress as you go....a rough guide is 30-40 of the size of the raw data....depending on how compressed it was.....
so if 220 G is the data size you have probs with the target partition of 10G.
I will leave it to you to decide.
btw....if you mean a server....you probably get a tax deduction for your expenses so a tape backup could be the way to go?