Raid on IBM x-series 206


I want to install openSuse 11 on an IBM x206 Server with onboard Adaptec sata-controller. I setuped 2 HDs as an array raid 1 and the the array status is optimal, but linuxsetup still detects 2 different HDs instead of the array. Do i need any drivers?

thanks in advance

Nobody an idea?
Please help !