Traditional RAID arrays (mdadm, hardware RAID controllers) use fixed stripe sizes and predictable parity rotation. A trained engineer with Data Extractor Express RAID Edition can detect these parameters and reconstruct the array.
BeyondRAID discards this model. It uses a thin-provisioning allocator that maps logical blocks to physical extents across drives, with variable stripe widths that change based on the number and size of installed drives.
When a Drobo is healthy, the chassis firmware manages this mapping transparently. When the chassis fails, the firmware becomes corrupted, or multiple drives degrade simultaneously, that mapping becomes inaccessible through normal channels.
Recovery requires parsing the BeyondRAID metadata tables directly from the raw drive images to reconstruct the logical-to-physical block map. This image-each-member-then-parse workflow runs entirely in-house at our Austin, TX lab and mirrors our broader NAS data recovery work, where every member drive is imaged offline before any array is reconstructed.
Drobo's thin provisioning adds another layer of complexity. The logical volume presented to the host (via USB, Thunderbolt, or iSCSI) can be 16TB or 64TB regardless of actual physical capacity.
Only allocated extents contain real data; the rest are unallocated space that the allocator would fill as data grows. The recovery process must distinguish allocated extents from unallocated space using the thin-provisioning bitmap stored on the member drives.
BeyondRAID is genuinely closed-source. It isn't Linux md-raid with a wrapper, and standard mdadm or hardware-controller tools can't read it.
The two structures that decide whether a recovery succeeds are the BeyondRAID Data Allocation Table (DAT), which records where every logical block actually lives across the member drives, and the thin-provisioning bitmap, which separates real allocated data from sparse empty space. We pull both out of the raw sector-by-sector images and rebuild the map by hand.
If you want the byte-level version of how we parse the BeyondRAID Data Allocation Table, that walkthrough covers the DAT layout, the thin-provisioning bitmap, and the variable stripe geometry in depth.
