The Data Robotics Drobo, despite the "storage robot" marketing label on it, isn't anything like what you might think of from a hacker/sci-fi movie where the robotic arm is swinging around in a see-through cabinet. (Those are usually giant tape library systems and not hard drives). But the company has managed to draw a fair amount of interest in the Drobo. MacBreak provided some video coverage of the Drobo products at 2008 MacWorld:
Cali Lewis looks at the Drobo at MacWorld 2008
While this is no way a web-design blog, I have to note that the Drobo web site is nice and well laid-out. Their product works with Windows and Mac OS, but you get the feeling that they strive to be very Mac-like (which is in no way a bad thing). Definitely a nice site to browse, compared to the usually sparse looking sites of other vendors.
The Drobo is small compact shiny black box that holds 4 SATA drives, which are easily hot-swappable; no brackets or any screws required, just slot them in. The faceplate is magnetically attached to the case, so it's very simple to replace or add drives. The unit is $499 and that is without drives. It only has USB to connect to the host system, but there's an optional Network Attached Storage (NAS_ attachment for $199 which will make the Drobo network-accessible.
Data Robotics Drobo
The interesting feature of Drobo is that it doesn't use the typical RAID levels for data protection. They use their own proprietary storage management that virtualizes the storage and disperses your data over all the drives. If I read their site correctly, your available storage is the sum of all the drives, minus the largest one. Per George Ou at ZDnet, the Drobo does seamless multi-level RAID on the fly, depending on how many drives and their capacities. So there's some mirroring with RAID 1 plus some Stripe+Parity (I'm not familiar with this, but apparently similar to RAID 5 in function) as you swap in drives. Read George Ou's review of the Drobo.
Another interesting tidbit is that the maximum volume size for this virtual disk is 2TB. Probably not a big deal for most home users. If the total space between your 4 drives is greater than 2TB, the Drobo makes multiple 2TB virtual drives available, e.g. 4x 1TB drives results in a 2TB and a 1TB virtual drive.
They definitely have the ease-of-use down pat. You can plug-n-play with any size drives, although you probably want to keep their relative sizes somewhat close. Using 3 tiny drives (40GB) with 1 big TB drive is not the optimal use-case for the Drobo. Their assumption is that you will have a range of drives, say 200-500GB and you swap out the smallest one for a larger one over time. One drawback users have noted is that assimilation of new replacement drives can take hours. Adding a new drive into a blank slot does not appear to have this problem though.
Anyway, I'm not trying to do a full product review (for one thing, I don't have one to test with), especially since many other sites have already reviewed the Drobo in depth:
Given the built-in volume management in the Drobo, I'm not all sure that ZFS is even possible on it, although it is a semi-compelling alternative to the whole ZFS approach. The Drobo is conveniently hands-off and simplified for consumer use. One unknown factor though is the proprietary nature of the volume management. A drive you yank out of the Drobo, are you going to only be able to view that data on a Drobo? If you had a ZFS setup and you had to yank one of a mirror-set's drives, you could technically mount that drive as a standalone drive and still retrieve the data (okay, I've never done this, but I'm just assuming this can be done?)
An interesting thread is here on Drobo's forums about Drobo vs. ZFS.
Anyway, I'm not especially serious about pursuing the Drobo as an option, but it is extremely interesting from a storage implementation point of view. It's definitely targeted as a nice plug-n-play solution for users that don't want to bother with their storage other than to dump files on it. The $499 cost may seem a bit high, but there's quite a number of other drive arrays or enclosures that are around the $400-500 range for a bare chassis, so the Drobo is not particularly out of line, given the hot swappable drives and the seamless variable level RAID built-in.
