You have my sympathies. I work in IT and so I know the importance of redundant (or double redundant) backups. I'm the DBA for my company and so I'm extremely picky when it comes to backup plans. Something like this demonstrates why companies spend tons of money on serious backup systems. Data is priceless.
My Photo + Music collection totals about 80GB. It all 'lives' on my notebook, but I keep two backup copies on two different external USB drives (one at home, one at work), and a third backup on an old Linux PC at home, just in case.
I don't know much about the DNS-323.... ok, reading about it...
D-Link's site says it's a RAID 1 array, which means your drives were just mirrored. Is that how you set up the RAID array? If so, that might be good, because there's no striping issues to deal with. If you were using a RAID 1 array, each of those 500gb drives should be an exact mirror of each other. If you know the drives are ok and it's just the controller that crapped out, your data might still be ok. Other RAID types stripe the data across multiple drives, and recovery is a bit more difficult with them. It depends on how the RAID 1 controller works (and I have no idea with the 323), but your data might be completely intact and easily accessible. Maybe.
Disclaimer: Ok, from here on out things could get dangerous. I'm *not* an expert on RAID arrays, but I know just enough to be dangerous. I can't promise that any of my advice will help, or maybe even further destroy your data. Take my advice with extreme caution....
Do you have a PC with a SATA controller? If so, remove one of the 500GB drives from the 323 and put it in your PC as a secondary drive. Boot with the PC's normal boot drive, of course, but that other drive should then be recognized by OS. You might get lucky and all of your files will be right there, and you could then just copy them somewhere else safe. I would think that this would be pretty safe to do, as either the data will be there or it won't. If that drive works, then the rest of your files ought to be on the second drive.
You could also try buying a second 323 and putting these drives in it and seeing if it would be able to read the data. Again, since we're not dealing with striping, it might just work. Of course, the danger here is that it would do some sort of auto-initialization and wipe out the data.
A third option would be to scour the net for details about how the 323 works. I'd bet that the 323 is a simple little Linux box. It's possible that you could find a group of tinkerers out there in another forum somewhere that could tell you how to re-build the array from an actual linux box and get your data back. That just depends on how much hardware you have lying around at home, and how confident you are in your abilities.
EDIT: Nevermind, I didnt' pay close enough attention to your post and now see that you were using them in a JBOD array.That changes things, since your data wasn't mirrored. There may still be ways to recover the data.
Seriously, Good Luck.
