How do most of you back up huge music/video libraries? Raid array? Software applications that mirror hard drives?
As Ken said, RAID ≠ backup. Let's say you have all your music on a pair of mirrored (RAID 1) drives. One day, one of those drives fails. No biggie. The other drive is an identical copy, so you've lost nothing. You just buy another drive of equal or greater size and you're good to go. Some time later, though, the RAID controller goes kaput, but not before corrupting some data on your drives. Oops, you may have just lost some music.
To prevent data loss, you need a backup. A good backup routine is to make an identical copy of your precious data and save it to a completely different device, preferably in a different location, at least once a day. There's plenty of software that will do this for you. Naturally, everything doesn't get copied over every day. Most software will only transfer anything that has changed since the last successful backup ran.
