Changing Hard Drive controllers with s/w RAID
 

I have a server with an onboard SymBIOS SCSI controller. It only supports up 40mb xfers. However, I have two U160 IBM SCSI drives mirrored together through the Linux s/w RAID tools (ie md0, md1, etc). on this controller. I have recently purchased an Adaptec U160 capable SCSI controller and want to install it and simply move the SCSI ribbon from the onboard controller to the newer, faster controller.

Does anyone see this as a major issue? Aside from ensuring my kernel has support for the new controller compiled in, will anything break? I'm used to the Sun/BSD world that assigns device IDs in the c0t0d0s0 fashion. Hence if c0 is the onboard controller and c1 becomes the new controller, and I move stuff over, it won't boot up w/o being reconfigured 'cause it's looking for a disk on c0. This is similar to how NT/2000 works. Is Linux the same? Are the c0t0d0s0 settings all just hidden from me? Or does controller order not matter if I only have one boot disk? I have lilo installed and the root dev is /dev/md4. Is the controller stuff hidden somewhere? Maybe /etc/raidtab?

I havent done exactly this however I have split the backplane of a server once when I installed some additional SCSI hard drives.

The machine wouldnt boot because /dev/sda became /dev/sdb and vice versa.

All I needed to do in this case was boot up in rescue mode and change my grub.conf (or lilo.conf in your case) to find the boot partition and away she went.

For you problem though as far as I can tell as long as you remove the old SCSI card or change the scan order in the BIOS so that your new one is first then it should assign the same device nodes as it did when you first set this up.