I’d recommend you read up a bit on RAIDs for exactly that reason, backup. A RAID 5 configuration is an excellent combination of speed and safety, because if one drive fails, you can replace it and it will rebuild itself with no data loss. However, you need a RAID card for this. Cal Digit makes a nice one, I use it myself.
The other issue you’ll run into is, if you take 3 hard drives and use them as you will and then decide you want to raid them together later, you will have to obliterate all the data on those drives. If you have ample space when you decide to do so, you’ll be fine, but if not, you could be up a creek. Just food for thought.
Also, while I know migration causes issues with pro apps, I’m not sure if Time Machine does or not, but I typically use Super Duper to create disk backups.
Richard Sanchez
North Hollywood, CA
“We are the facilitators of our own creative evolution.” – Bill Hicks