I have a host with three 120G internal disks and have a RAID 1 mirror
set up which autoconfigures at boot to be the root device.

I've added the third disk as a hot spare but I find that this
information isn't retained if the machine is rebooted for any reason and
I have to manually add it again.

If it were not an autoconfig RAID set I'd fix the problem by tweaking
my /etc/raid0.conf, but I'm not sure how to do it in this case ... any
ideas?

Regards,
Malcolm

-- 
Malcolm Herbert
Computer Support Officer
School of Geosciences
Monash University
ph 9905 4881