Thank god you're not running IDE like most of the PenguinOS devotees running servers these days.
However, Quantum drives are now Maxtor drives, since Maxtor bought their tech, and is reselling them. Actually, they're pretty much blowing them out. Pricewatch will help you find very cheap replacements.
Then again, I'm a Seagate person myself here, since I've had good experiences with them here (and have gone through many many many Barracuda and Cheetah drives with 2 failures in 4 years).
I guess time to start thinking RAID
.
Mitch