I have a new iMac and a few external drives, but i am almost oout of space, so im looking at what otehr storage options i have. I think im interested in something like a RAID setup, but im not really sure what i need. I would like it to be pretty expandable for the future, and it would mainly be used for movies and tv shows. I have looked into UnRAID a little but im not really sure if thats what i want. It seems sorta like thats building another computer, and i kinda would like the imac to be the brains behind the operation. I guess im really open to any suggestions. What do most mac users use for large file storage/ backups?