I use superduper to clone my mbp hard drive. I use smart update. Do you think it is the best option? Does it transfer only what changed from the last backup? And what about files that now do not exist on the original hard drive? Does it adds space on its backup data all the time? My hard drive occupy about 40mb and it is has total 120mb. If it do not delete files that do not exist now, it will need so much space on my external hard disk in the future. Answer if you know how it works. You can also tell me any good backup plan you do about your data backup. Except from superduper I write my data files to dvd for extra security. Is it better from time to time to stop doing another smart backup with superduper and start from scratch doing a whole new backup?