Drobo Pro

Data Robotics, maker of the Drobo storage products has rolled out a nice looking high-end product that is essentially a double-wide Drobo, taking on up to 8 SATA drives:

Images courtesy of Drobo

The Drobo Pro has 8 drive bays and 3 ways of connecting to a host system: iSCSI, Firewire 800, USB 2.0.

With up to 8 drives, the Drobo now supports double-parity to survive the outright failure of 2 drives. With typical ZFS RAIDZ2 you'd need at least 5 drives (3 data + 2 parity) to support double-parity, so I'm going to assume you'd need at least 5 drives in the Drobo Pro as well for double-parity. Although technically they could default to mirroring, if you only had 4 drives, but that would cut usable space by half.

The Drobo Pro even comes with a rack-mount kit, although looks a little goofy with the 2 "wings". Seems like they could just fill it out to 12 drives across and make use of the dead space. Also, they don't list the depth of the unit, but I imagine it's relatively short compared to most rack-mount gear. So in terms of rackspace, the Drobo Pro probably isn't the most efficient use of space, but maybe fine for smaller shops that might just have one or a few racks.

Personally, I still prefer one of these Sun Fire X4500 rigs, packed with 48 drives, but sadly it's in a different price range (starting at say $20k) :)

There's a a good write-up at Mydl.me and of course the normal info at Drobo's own web site.