Comment Enterprise Backup at SMB costs (Score 1) 272
I haven't seen anyone in this thread mention SymForm http://www.symform.com/, which may well be an ideal solution for your situation. This is a fairly new startup operation founded by former Microsoft and Amazon engineers that manages a cooperative cloud backup platform. You'll need to do some reading of the whitepapers on their website to wrap your brain around the concept, but the gist of the idea is that you configure your spare storage device (like your Drobo box) to form a node that connects to the cooperative cloud, which is comprised of free disk space on the spare storage devices (SAN, NAS, external SATA drives, etc.) of the other members of the cloud. With 5,000-10,000 other nodes sharing exabytes of free disk space, there is plenty of capacity for all the members of the cooperative, and as the cloud is distributed worldwide, there is no single point of failure to worry about. The data is fragmented in such a way that it is distributed randomly across multiple nodes (in a system they call RAID-96) so that no single node in the network contains a complete copy of your data. You pay a flat monthly fee to join the cloud, and your data is encrypted by your node and backed up incrementally over your network connection. It may take a while to get your first full backup transmitted, but after that, the bandwidth is used only for deltas. It's kind of a brilliant idea that blew me away the first time I heard about it.