No, you’re mistaken. I know nothing of Drobo but I do know RAID, and you are significantly misrepresenting the state of the art. Neil Brown’s mdadm is backwards compatible to previous Open Source RAID mdtools implementations (including previous versions of on-disk structures) and does not require any specific hardware or firmware. I can RAID any group of block devices together, no matter how heterogenous (ATAPI devices, USB devices, ISCI targets, DRDB volumes, AoE etherdrives, whatever as long as it’s block storage). I can do this using one version of OS, firmware and controllers and move the storage media to completely differing versions of OS, firmware, hardware, drivers, etc. trivially.
Also, both dmraid and mdadm support SNIA DDF metadata and on-disk structures. dmraid also supports Highpoint, LSI, Promise, and SI Medley hardware and formats, and mdadm can support the volume metadata format used by Intel Matrix RAID chips. There’s significant cross-compatibility in the FOSS world with non-free RAID implementations, although that’s a recent phenomena.
I’ll accept that most people haven’t the specialized knowledge I have and that’s a perfectly valid point for you to make if you are shipping product for a larger audience than professional computer scientists. And it’s also true that there are huge incompatibilities between vendors of so-called “hardware” RAID controllers. But please do not claim “every RAID is proprietary. You can’t just take a drive out of a RAID, pop it in a PC and read the data” because there are cross-compatible RAID implementations, where you absolutely can do that.
