I picked up a DROBO storage device from a friend of mine who had too many. I plugged the device in to my Linux file server and the DROBO appeared as a standard hard drive. I was able to partition the drive normally, but I had a problem when I tried to format the device.

Apparently the DROBO appears as a 16 Terabyte drive regardless of the amount of storage actually installed. The DROBO keeps track of how much space is used internally and communicates this info via a series of LED lights on the front as well as by its own API (in other words you need a 3rd party app to get this info since the DROBO is essentially lying to your OS). The idea is that if you run out of space you simply plug in a bigger drive and the Drobo will on the fly integrate the new bigger drive.

Anyway, a mkfs.ext3 (the DROBO supposedly supports this file system, and it needs to understand the file system at the block level to do its magic) fails because it tries to verify each inode. Of course the majority of them will fail since they don't actually exist yet (I only had 4 x 1 terabyte drives installed). What I needed to do was pass the -F flag to mkfs.ext3 to make it ignore the errors and proceed with the format. man mkfs.ext3 for more details and other flags.