> which you can maintain using 
> 	mdadm --detail --scan >> /etc/dadm.conf 

I assume you mean mdadm.conf?  Yup, we already have that and everything's
working "normally", except we have to manually start raid at boot time.

> and with the right option in /etc/fstab it would be mounted.

Didn't check that, but in my recollection /etc/fstab only contains the md
device to mount.  The md device needs to be set up by mdadm before it can be
mounted, hence mdadm and/or raidstart need to run in rc.sysinit.

> I didn't do that yet, so i was surprised to see that one seems
> to have to run
> 	mdadm --create .....
> each time before /dev/md0 is in the correct shape so you can mount
> it again.

I don't think so; you --create the first time, and from then on you
mdadm --assemble --scan.

I suppose I'll set up a mini-HOWTO for this, if I don't find any others.
I've seen a few posts via google which point to patching rc.sysinit to check
for /etc/mdadm.conf and setting up raid via mdadm if it exists.  Thus, I
believe I was on the right track.

Good luck,
Dan W.