and the client could not read either one. A WD My Book Duo mirrors every file onto two disks. One disk died. The survivor held a complete, perfect copy — and it was still unreadable. This is the part nobody tells you about two-bay enclosures.
← All case files · £300 + VAT, flat
A My Book Duo stopped responding. One of the two disks had failed. RAID 1 is a mirror — every byte written to one disk is written identically to the other — so by any reasonable expectation the surviving disk should have held a complete, working copy of everything.
It did. And the enclosure would not give it to them.
Three things stand between you and a perfectly healthy mirror disk, and consumer two-bay enclosures have all three:
The enclosure writes its own RAID metadata to the disks. Pull a member out and connect it to a SATA port and the partition does not simply mount — the layout is described by headers the enclosure owns.
The My Book Duo encrypts in hardware, on the bridge board — exactly as the My Passport does, and for exactly the same reason. The key is in the enclosure, not on the platters. Take the disk out and you have noise.
The controller refuses to present a single member standalone when its partner is missing, which is precisely when you need it to.
So: two complete copies of your data, both physically intact, neither readable. That is not a fault. That is how the product works.
— genuinely dead, not merely dropped from the array.
, holding a full mirror of every file.
, so nothing would mount it.
The volume was rebuilt from the surviving mirror and the studio's work came back.
What decides a job like this is not the failed disk — it is whether the survivor is genuinely healthy and whether the bridge board lived. A mirror where both members have been quietly accumulating bad sectors for years is a much harder job than it looks, because people assume redundancy means safety and never check either disk.
RAID 1 protects you against a disk dying. It does not protect you against anything else, and it is not a backup.
A mirror copies your mistakes at the speed of light. Delete a file and it is deleted on both disks instantly. Ransomware encrypts both. A power surge through the enclosure takes both. Drop the unit and both are on the floor. There is no version history and no undo — there is just the same thing, twice, in the same box, in the same room.
If it matters, it needs a copy somewhere else. And when the enclosure does fail: send the whole unit, both disks in it. The bridge board is holding your encryption key.
Drop the drive at our Quayside reception, or post it to us — it costs nothing to find out what happened. You get a written figure from the fixed bands before any work begins.