Sorry, don't now how to install the driver to boot from the raid array, i'm using the controller to get a lot of space and mounted the extra space to a ibay.
Just copy the driver to /lib/modules/2.4.20-18.7/kernel/drivers/scsi and from the console do a insmod 3w9xxx and mount the extra drive. There are a lot of how-to's to do that.
Just search the forums for the information. It's there.
)
Tonie