Mark -
Welcome to the NetApp community !
I'm sure there's folks here to shed light on your problems...
Do you have your NOW.netapp.com access ?
http://now.netapp.com/NOW/public/knowledge/docs/hardware/filer/210-03951.pdf
Have you found the documentation pages on filerview ?
( http://myfiler/na_admin )
You're correct that you're running with no spares on at least one filer,
but if you see 'partner' disks you've got a cluster. There's another head
for you to log onto and check out.
How many disks total do you have ?
How many aggregates ?
If you've got a dparity disks you could go down to RAID4, but I wouldn't want to.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
ekashp@kashpureff.org
Senior Systems Architect / NetApp Certified Instructor
http://www.linkedin.com/in/eugenekashpureff
(P.S. I appreciate points for helpful or correct answers.)