I would assume this is a recent vintage Dell server with a newer model Perc RAID controller (probably one of the 4/ series).
If this is the case, you need to grab the RH drivers from the Dell website (start from
http://support.dell.com/support/downloads/index.aspx?c=us&cs=04&l=en&s=bsd I guess).
The Perc drivers (also known as 'megaraid' drivers) drive the rebadged LSILogic (previously AMI) series of RAID controllers (similar to the NetRAID series of HP controllers).
I doubt however that you'll find one for RedHat 9.
One long-haired git at your service...