I have an external HDD currently formatted in two partitions for my windows laptop and my mac mini to back up to. I got a used powerbook and want to use Carbon Copy to make a bootable image/backup using this same extl HDD - ie: I need to reformat and make three partitions (one for manual backups with windows laptop, one for time machine on mini, one for carbon copy on the powerbook). I am aware that Time Machine uses a fair bit more space for its recurring backups than the actual amount of my HDD (ie: it backs up 90 gigs worth of data and over time it turns into a 140gig backup). So to the question: The HDD in the powerbook is 60 gigs. Should I just set aside 50-60 gigs on a new partition for backups?... or does carbon copy do something like time machine, where it takes up more space for the backup than the actual files do? I just don't want to reformat this all wrong. Thanks!