Scott> We are considering a FAS3220HA running clustered ONTAP (8.2) Scott> with a single DS4246 shelf. However, we were recently informed Scott> by our sales people that this is not possible, and that the Scott> minimum number of shelves for an HA pair running cDOT was Scott> two. Apparently each node needs it's own DS4246 for the cDOT Scott> operating system? Is it not possible to split the disks on a Scott> single shelf into two aggregates and assign one aggregate to Scott> each controller?
Each head needs it's own boot disks, and since it's hard-coded to boot off slots 1 and 2 (or some other pair, I forget) in the shelf, having just one shelf would not allow the other head to boot.
Personally, I'd probably gamble that a single 3220 with a single shelf doesn't really need clustering since you're obviously (to me at least, please correct me if I'm wrong) not looking for capacity or even massive performance, since you have a small number of spindles. But I could be totally off base here.
John