How to duplicate a HD using dd

[Thiago Vinhas de Moraes]

Hi!

Sory for the OT, but does anyone the best way to duplicate a HD in
Fedora, just like Norton Ghost does in Winblows? 

I tried to use dd if=/dev/hda of=/dev/hdb, but the proccess has never
stoped, after a few hours. 
Both are 40Gb hard drives, but from different manufacters. One is a
Maxtor, and the other one is a Samsung.

Thanks in advance,
Thiago