Here is my situation. My 300 gig computer hard drive was almost full till I got a large backup 2TB hard drive to hold all that is on my computer plus the extra files I have accumulated. I do have two 750 gig portable external hard drives that I alternate with one always kept at a relative’s house. However, the problem is that while one of those portable drives backs up data I will remove extra data to the large 2TB drive and when I alternate portable drives the data transferred will not be on the new portable drive. I know that is a little confusing, but let’s just say it is timing issue where the only drive that holds it all will be the one large 2 TB drive. So I thought Carbonite would be a good second choice.