Two Options:
If you use the controllers on-board the system, you need to tell linux that the Promise controllers should be enumerated first. Two steps here. First you need kernel support for this
Code:
CONFIG_BLK_DEV_OFFBOARD=y
also you will need the support for the promise kernel
Code:
CONFIG_BLK_DEV_PDC202XX=y
Then you'll need to boot the system and pass the following command to the boot loader (at the lilo prompt). For Kernels > 2.4.x
Code:
[your boot label] ide=reverse
For 2.2.x kernels
Code:
[your boot label] pci=reverse
. (THe boot label is the one in lilo.conf for each bootable kernel you have. Go have a look - you'll figure it out.) The tricky part is that if you have more than one controller card, your original card sequencing will be reversed. ie: if you had /dev/hda on controller 1(primary) and /dev/hde on controller 2(primary) they would switch positions in the enumeration sequence so that what was once /dev/hda would become /dev/hde. The positioning of the primary and secondary controllers on each card will be the same (primary is still primary), I probably made that sound more difficult than it really is...
OPTION 2:
If you don't want to use your on-board controllers, just disable them in your BIOS or tell your bios to boot off-board or SCSI controllers first. What you do will depend on your BIOS software.