Comment Re:RAID? (Score 1) 256
I have an external 2TB drive I use for backups. (In addition to DropBox for critical files, although I've been reconsidering that particular service lately.) I unplug it when not in use. So in the same system broadly, but not really. It's a consumer system, so no need to go as silly as having a separate BDR box.
Off-topic, but I would advise you to keep off-site backups as well. A friend of mine kept three physical backups of all the pictures and videos of his kids, which where completely useless when his house was burglared and they stole all his computer equipment. He lost everything, and those files were invaluable to him, he would have paid any amount of money to get them back. Anything can happen to a single physical site, from a fire to a direct lightning strike which fries all your equipment. Use a fire-and-forget off-site backup solution to mitigate those risks.
I use Crashplan to keep off-site backups at a friend's place as well as the cloud, but any service that enables you to keep a complete off-site backup is probably OK. Crashplan enables me to keep backups of everything, not just "critical files". Oh, and test recovery as well.