Last time I lost data was in 1993. (edit: I trusted Microsoft backup...) There are several strategies for backing up data. Some rely on others (less reliable if you ask me) and some are totally reliant on the user (I find that more reliable.) The most important step in a backup strategy is the discipline required when that data is created or acquired. Most people don't have the discipline necessary. It usually takes people one or two times of losing all data to figure out a backup strategy that works for them. Some people never figure it out. And some people refuse to follow through on a suggested strategy for them. Some people are familiar with the definitions of RAID. My backup strategy exceeds the definition of RAID 10. I don't use any compression, I don't do incrementals, I don't do differentials and I don't use "the cloud". I can lose up to 6 of my backup drives and still be able to do a full recover. It depends how bad you don't want to lose data and how much discipline you have.