Don't forget that you should have a RAID set up for actual redundancy of data while working (That way if a drive fails you aren't down for the day getting it fixed and trying to restore from the latest backups), and that RAID is Not A Backup.

RAID is something that should be treated as a method to simply keep a system running through a failure, and to make a hardware failure easier to fix and get the system back on its feet. It still needs proper backup and archiving methods, ideally one of which is off site if your business is highly data related.