WHAT ABOUT RAID?
RAID drives, as you might imagine, can be tricky beasts to recover data from, and certain configurations introduce issues of their own. Run a striped set in RAID 0 formation, for example, and you’re asking for trouble— yes, you’ll have some of the fastest storage going, but if one of your drives goes down, you’re stuck. There are various options that claim to be able to recover files from RAIDs 0, 5, and 10—ReclaiMe (www.freeraidrecovery.com) is the most prominent—but don’t hold your breath for any decent results. On the flipside of the coin, RAID 1 and similar mirrored configurations positively aid in data recovery; if one of your drives goes down, you may need to invest a little time and money in remirroring with a new drive, but catastrophic failure is only going to come from your own hand or a malware attack. If this is the case, you have the same chance to recover files as you would with a single drive.
The other issue RAID introduces is the controller itself. If whatever’s managing your RAID configuration—your NAS, your main computer, or specialist RAID hardware—goes bad, it could throw your drives into a position where recovering data is entirely impossible. It’s not unknown for specialists to be able to engineer specific tools for specific instances of RAID failure, but this is a highly costly procedure, with no guarantee of success.
We don’t have an answer for the irony of RAID being both safer and more dangerous than storing on a single drive, other than to suggest, again, that you always keep stringent backups away from your regular hardware.