Slackware 14 boot issue after adding new SATA controller
 

I added a non-raid 9215 SATA adapter card to accommodate my growing disk farm. After doing so, the system booted OK, until I added hard drives to the adapter.

Then I get a message that I need to change the root= boot option, that root device 803 (or 8,3) is unknown.

In BIOS the new SATA card is not visible.

What suggestions might there be to permit booting as before, but in a way so that it doesn't matter whether this SATA adapter has discs connected to it? This system actually has an old 60GB IDE harddrive, which is the system drive. All the SATA drives are data.

I think what is happening is that the 9215 card drives are being used, after the initial memory load on the boot. So the system subsequently does not see the IDE drive.

You can't really control how drives are enumerated by the kernel, unless you compile all controller drivers for non-boot devices as modules and load them manually in a specific order.

I'd recommend using an initrd and specifying the root filesystem label or UUID in /etc/fstab rather than the device name. That way, the kernel and initrd will be loaded by the boot loader using the motherboard or controller BIOS, and once the kernel is up and running it will locate the root FS based on label/UUID regardless of the actual device name.

I have a post on converting your /etc/lilo.conf and /etc/fstab to UUID. You may find it handy.