Perez Studios

I have been wondering where do you professional photographers store your photos after so many years?  I have a 1.5TB drive as my Main drive and another 1.5TB drive as my backup which I use Storage Craft’s Shadow Protect to backup but what do the pros use?  I use Adobe Lightroom 2.0 to keep track of all my photos but as I begin to run at about 300GB left on the 1.5TB Main Drive I am wondering should I archive them onto DVD and keep them in a safe or what? 

Anyone with any ideas I would appreciate the help!