Most discussions of ZFS suggest that the hardware RAID be turned off and that ZFS should directly talk to the disks and manage the RAID on the host (instead of the RAID controller).

This makes sense on a computer with 2-16 or even more local disks, but what about in an environment with a large SAN?

For example, the enterprise I work for has what I would consider to be a modest sized SAN with 2 full racks of disks, which is something like 400 spindles. I've seen SAN shelves that are way more dense than ours, and SAN deployments way larger than ours.

Do people expose 100 disks directly to big ZFS servers? 300 disks? 3000 disks? Do the SAN management tools facilitate automated management of this sort of thing?