I am using kubuntu 10.04 and now I want to install Mac on my PC.
I have my data scattered in over 200 Gb and I want take a backup such that with one command all my data is saved into a single file.
Then if my MAC installation fails then just format my hard drive and restore the system in its original form.
I know about "dd" but I am skeptic about it .
Is it possible?

dd, it is rock solid and proven ;) – Tim Jun 8 '12 at 13:02ddis NOT a backup utility; it's a low level debugging swiss army knife. – psusi Jun 8 '12 at 23:15