Drobo BeyondRAID Data Recovery

BeyondRAID is what made Drobo easy to use – and what makes Drobo hard to recover. Instead of a fixed RAID level, a Drobo splits every drive into small regions, decides for itself how to protect each piece of data, and keeps a private map of where everything is. That map, not a standard RAID layout, is what your files depend on.

No operating system can read a Drobo disk pack on its own, and ordinary RAID recovery software doesn’t understand it. Recovering a Drobo means reading and interpreting BeyondRAID’s own metadata.

How BeyondRAID Works

• Mixed drive sizes – each drive is divided into regions, and data is protected across whichever drives have space, so capacity from a 2TB and an 8TB drive can be combined
• Single or dual disk redundancy – chosen by the user, with the Drobo re-laying out data automatically when drives are added or fail
• Thin provisioning – the Drobo presents a large virtual volume (16TB or 64TB depending on the model), much bigger than the space actually available
• A Data Allocation Table – BeyondRAID’s private map recording which chunk of data lives where. It changes every time the Drobo re-lays out data
• The file system on top – on direct-attached Drobos (5D, 5D3, 5C, 8D, Mini), your Mac or PC formats the virtual volume as HFS+, APFS, NTFS or exFAT. On NAS models (FS, 5N, 5N2, B810n), the Drobo formats it with a Linux file system

Why Drobos Fail the Way They Do

Because the Drobo constantly relocates data, a drive that fails part-way through a re-layout can leave the map describing a layout that was never completed. Power cuts during this process, a failing accelerator SSD, or several ageing drives failing close together are the most common causes of a Drobo that won’t mount. The data is usually still on the drives – the Drobo has simply lost confidence in its own map.

How We Recover a Drobo

• Image every drive, repairing failed drives in our cleanroom first
• Locate and read the BeyondRAID metadata on each drive, including older copies of the map
• Choose the most recent consistent version of the map and use it to reassemble the virtual volume
• Repair and read the HFS+, APFS, NTFS, exFAT or Linux file system on top
• Verify your key folders with you before copying the data to a new drive

Moving Away from Drobo

With Drobo gone, every working Drobo is on borrowed time. If yours still works, copy your data off now – ideally to two places. For a replacement, a Synology or QNAP NAS with SHR or RAID 6, or a Thunderbolt RAID enclosure for Mac users, offers similar convenience with ongoing support. See Synology, QNAP and G-RAID.

Frequently asked questions