Cooool

But

How are you backing this up? If your reference to DAT/DLT is 'cos that's the backup mechanism then fine, disregard the rest of this post... but for anyone considering RAID read on...

I used to run RAID - it's fun, it's what big systems do, hey, it must be the right answer...

WRONG!! (or at least - it's not a slam dunk)

IMHO Most people shouldn't run RAID at home (well, not for mirroring anyway).
Mirroring means that both disks have the data written to them instantly - great.
Data is also blatted instantly if you accidentally do something bad - like corrupt a database, hit delete on the wrong directory etc etc. Even get a virus. And that's generally a lot more likely than a hard disk failure (unless you run IBM deskstars )

I suggest that you have seperately mounted disks and an automatic nightly (or hourly if you like) backup from drive A to drive B.

Then, when (not if!) you cock something up and get that chilled, scared feeling you find that your quiet backup disk is worth an awful lot...
This happened to me when I accidentally killed the partition with *all* my irreplaceable digital photos - whilst trying to replace the failed mirror drive - and believe me I nearly cried! (Luckily in my backup paranoia I'd copied this onto yet another spare partition 2 days before and all I lost were the date stamps - every photo is now 8/July/2002 10:22 - in the 30 seconds until I remembered this I was actually shaking - weird but true!)

For those who run a linux server look here:
http://www.mikerubel.org/computers/rsync_snapshots/

Robricc, you sound like you have the know-how to run rsync on windows so take a look and see what you think...

Rsync
http://rsync.samba.org/
on windows:
http://optics.ph.unimelb.edu.au/help/rsync/rsync_pc1.html

By the way, rsync was written by Andrew Tridgell (of Samba fame) and is a way of comparing and synchronising data across a network without transferring all the data...