Boot tip when using two RAID controllers (onboard + PCI)

[armakuni]

I just thought I'd share something that took me a couple of days to figure out.
I had a 2.6.22-gentoo-r8 system running on a RAID 1 consisting of two 150GB SATA drives connected to my onboard Promise Fasttrak controller on my motherboard MSI K7N2G.
I wanted more SATA disk space so i bought 2 new 500GB SATA drives and an Adaptec 1420sa RAID controller card.
I recompiled the kernel with the driver for the card, plugged it all in and rebooted.
Now my system could not find a bootable device. It ran through the Adaptec BIOS then the Fasttrak BIOS and then the Nvidia Boot Agent started trying to PXE boot. It stopped with a disk boot failure.
The wierd thing was that if I unplugged the drives from the Adaptec card it booted just fine.
I tried every possible boot order, replaced the cables and tried a couple of different kernel drivers but still no luck.
Then I realised that when no drives was plugged into the Adaptec card the BIOS said "BIOS not installed" but when I had the drives plugged in it said "BIOS installed". So I went into the Adaptec BIOS (ctrl+a) and disabled the cards BIOS. When I rebooted everything worked perfectly!
I guess that I can't use the Adaptec hardware RAID now but I'm ok with running everything on software RAID.
Maybe this is self explanary to many of you but hopefully this post can help someone with the same problem!

[Jimmy Jazz]

Hi,

same problem with