I hope this isn't too stupid of a question, but this is a newbie board, so I'm hoping it's appropriate...

I am about to install a 120GB drive as the second drive in my HDR2. I may eventually want to replace the original 40GB with another 120GB drive, but it made me start to wonder... how does the HDR2 arrange files on the two drives? Does it first fill up the main drive and then go to the second once the first is full?

Just trying to collect some info... thanks.