Alright, here's the low-down; I would like to copy my HDD onto a second one, and then try and boot off of the second. The big thing is... The first HDD would be running the system at the same time as the cloning. What program should I use, or how should I go about it? They are two different sizes of drive (the smaller being the second, but the amount of data on the first I wish to copy is still less then my boot drive) I assume Carbon Copy Cloner, from some offhand remarks by other members, may not work this way... so that is why I happen to be confused. Any suggestions? Any clarifications?