FC2 - Booting from remaining raid disk

[Matthew Claridge]

Hi,

I've got a basic FC2 installation, using software raid 1 across two IDE 
hard disks. Each hard disk is the master drive on its controller (so one 
is Primary master and the other is secondary master).

If I remove the secondary master drive and boot the machine, all is 
well. If I remove the primary master, linux fails to boot (the bios 
cannot find an OS to boot). Even if I connect the secondary master hard 
disk to the primary master controller, it still cannot boot. So its as 
though linux hasn't mirrored the boot image successfully across the two 
disks.

There are three partitions on these disks, /dev/md[0-2]. /boot is on md0 
and / is on md1. Grub is installed on /dev/md0.

There's an easy way around this, which is to use a boot disk, which 
should boot regardless of which disk has failed, and I know that linux 
will carry on working happily if either disk fails, but I'd like to find 
out why its misbehaving and correct it so that it can boot normally 
after a disk failure, making the whole thing a bit more resilient, 
especially if there's a delay obtaining a new hard disk or something.

Anyone got any ideas?

thanks
Matt