SATA conflict with SCSI - SATA drives prevent SCSI DVDs to boot

OpenSUSE 11.2 server, Gigabyte GA-MA790X-UD4P
SATA: Promise EX-8350 [sda RAID1 for NOS] [sdb RAID1 for data]
SCSI: Adaptec AHA2940UW SD-M1401 DVD ROM & SONY SDX-500 tape drive
Video: ATI X550PCIE256, 600W PS

SCSI CD/DVD ROM reads CDs & DVDs fine as a data source, however when booting from a CD/DVD the result is a hang after the initial read. For example:

OpenSUSE 11.2 install DVD boots to the welcome screen, waits for my selection, displays “Loading Linux Kernel” then stops with a black screen & flashing cursor. Knopix had the same result. Gparted started to load but terminated with a screen full of textured symbols. Ultimate Boot CD for Windows inspects the hardware but never proceeds, Windows XP install CD did the same.

Here’s the kicker: Remove all SATA hard drives and the CDs/DVDs boot just fine. Must be a hardware conflict.

As part of my diagnostics I tried a SATA DVD drive and all booted fine. Yes, I could dump the SCSI DVD ROM, but I’d rather understand the problem and resolve it.

Thoughts or suggestions?

Switch the mode from SATA to AHCI In BIOS setup.

I’m confused you have two drives with RAID 1 but different data???

RAID requires the use of two or more drives. RAID 1 would be 2 drives with mirrored data. ie the same data would be on both drives. What you outlined does not make sense.

Raid array #1 is the operating system: (2) mirrored 500 GB drives
Raid array #2 is data: 2 mirrored 750 GB drives