A NAS is a small computer with disks attached, so “I can’t reach my files” can mean four different things — and only one of them is a data problem. Underneath the closed interface, most units run ordinary Linux software RAID, which is why a dead appliance is usually a better prospect than it looks.
$ mdr diagnose /dev/nas → NAS: Synology DS920+ · 4 × 4 TB · SHR → Status: VOLUME CRASHED — disk dropped, Btrfs damaged → Client: confidential · Manchester M2 $ mdr engineer-working → Member disks: all 4 imaged read-only → SHR + LVM: reassembled off the box → Btrfs: repaired · volume mounted $ mdr verify → ✓ shares — 11.2 TB → ✓ photos + backups — restored → ✓ NAS recovered — data back
A dropped member may still hold most of its data. Putting it back can start a resync in the wrong direction — overwriting the good copy with the stale one — and on a degraded array there is no redundancy left to absorb that mistake.
A NAS is a small computer with storage attached, so “I can’t get to my files” can mean four quite different things.
Every NAS runs broadly standard storage underneath. What differs is how many layers the vendor stacks on top, and that decides the work.
The window between a NAS reporting a fault and losing the volume is where this is decided.
A degraded array still reads. That window is the cheapest recovery available and it closes without warning — get the important material onto something else before touching the unit.
Rebuilding reads every sector of every survivor, which is precisely when a second disk with latent bad sectors gives up. Secure the data first, rebuild afterwards.
It may hold more than the unit thinks. Reinserting it can trigger a resync that overwrites good data with stale data.
1, 2, 3 and so on. Order can be derived by analysis but having it saves time and cost.
The exact wording of the error, and whether a rebuild ran. That detail changes the approach more than the model number does.
Priced by the reconstruction rather than the capacity.
NAS recovery starts from £500 +VAT, confirmed after a free 48-hour diagnostic. Physical drive-level work on a member carries a 50% deposit with the balance payable only on success.
Send the whole unit or the disks in bay order — both work. Drop-off at Peter House on Oxford Street, Manchester, Monday to Friday 9am to 5:30pm, or post insured. For business clients, NDAs are standard and invoicing is available.
Get the NAS to us, and tell us the make, bay count and RAID type. The diagnostic that follows costs nothing, and one figure goes in writing before any work begins.
Nothing starts until the NAS — or all its disks — to us is on the bench. Pack it properly and put your contact details in with it. Label the bay order if you are sending disks. The diagnostic that follows costs nothing, and one figure goes in writing before any work begins.
Posting it? Use something tracked and insured — whatever is on the drive is worth considerably more than the postage. Bringing it in? Weekdays, 9am to 5:30pm, and it still wants packing as above for the journey.
Not sure it is worth sending? Tell us about the NAS, RAID type and fault, plus anything already attempted — an engineer reads every one of these and comes back with an honest view of the odds and a price band, before you post anything.
We’ll be in touch shortly. If it’s urgent, call 0161 871 0788.
The questions we’re asked most about recovering data from a NAS.
Synology, QNAP, Buffalo, Netgear, Terramaster, WD and Drobo, plus white-box Linux builds. Most run standard mdadm underneath, so the brand affects how many layers sit on top rather than whether it can be done.
Synology Hybrid RAID — not a RAID level but layered mdadm sets sized to allow mixed-capacity disks. It is not proprietary, but the layers must be reassembled in the order they were created rather than treated as one array.
No, and this catches people out. A single-bay unit is one disk in a network enclosure with no redundancy whatsoever. It feels safer than a drive on a desk and is exactly as exposed.
Very likely not. Network-layer faults look identical to storage faults from a user’s desk. A changed IP, a failed port or an SMB version mismatch will all produce “cannot access” while the volume underneath is perfectly healthy.
Usually. A stalled update can leave the appliance unbootable while the disks are untouched — which is the good case, because the array is reassembled outside the unit anyway.
From £500 plus VAT, fixed in writing after a free 48-hour diagnostic. Physical drive-level work on a member carries a 50% deposit with the balance due only on success.
Underneath the branding most of these are standard Linux storage — mdadm or ZFS with ext4, XFS or Btrfs on top — which is why the appliance can be set aside entirely once the disks are imaged. The proprietary ones need their layout deriving instead.
Names with an arrow have a guide of their own — brand-specific faults, and what they mean for a recovery.
From £500 +VAT after a free diagnostic, whatever the badge on the front. Send every disk, labelled by bay if you can — and do not let it start a second rebuild or a scheduled scrub while you decide.