[Wylug-help] Raid problem

[Roger Beaumont]

I have a small network at home with a server-box that (amongst other jobs) 
acts as a file-server.

Naturally, the existing disks (190GB, RAID 1) filled up so I've added a 
SATA card and 2 Seagate 250's (sda & sdb), each partitioned as single, 'fd' 
partitions, then 'mdadm'ed together as /dev/md9 (another mirror array) with 
an ext3 filesystem.

So far so good - after 3 hours synching it's all up and running, with md9 
mounted temporarily on /newraid so I can copy the files from 
/space/shares/data/ onto it.

Then something hangs the box (or I 'init 6') and while md0 to md8 
reactivate just like they always have, /dev/md9 has disappeared ['no such 
file'], so I have to reassemble the raid and remount (and there's another 3 
hour re-synch until the data's all secure again).

At one stage I made the mistake of adding md9 to fstab - which meant that 
the boot process aborted because /dev/md9 wasn't found, and until I worked 
out what I was looking for and found mount -o remount, the whole box was down.

If I'm right, the first thing to fix is the problem that /dev/md9 
disappears on re-boot.  Anybody know why, and how to stop that happening?

Thanks in advance,

Roger
(Not quite a total newbie, but lost once I try anything new),