I think this link tells it all.
http://www.ubuntu.com/support
I see many options from digging through any Dell documents, restoring from the last good backup to the link with Ubuntu forums and the support services there.
I've done RAID many times over the years and the lesson is simple. Backup, backup, backup and collect the documentation or don't do RAID.
Bob
Hi,
I have a precision 690 (via ebay) that dropped a sector in it's virtual raid disk. I have bought two new drives, and was wondering how to get the integrated sas controller to see them. I don't have the dell support disks. I'm an ubuntu user...
What are my options folks?
Thanks

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic