Drive reordering
 

I have a RHEL4 server that is supposed to be attached our SAN. It boots up fine if the fiber cables are not connected. If the fiber cables are connected, the internal drive is no longer at sda. The HBAs are from Qlogic. Does anyone know where the scan order is configured? I need to keep the internal drive a sda.

Start booting both ways but enter the grub shell. Use the autocompletion feature to explore whether the internal drive is mapped differently. E.G. if it changes from (hd0,0). This may be what is changing rather than /dev/hda. You might try editing the /boot/grub/devices.map file which maps /dev/hdXX to (hdN,N).