Network attached storage has moved out of the server room and into the hall cupboard. At home a NAS streams films and music to the TV, phones and tablets. In an office it lets a team share files without the cost of a dedicated server. At Kensington Computer Repairs we recover data from both sorts, and from the RAID and SAN systems that sit alongside them.
If your NAS has failed, switch it off now. Do not pull disks out of the unit, do not change their order, and say no to any prompt offering to rebuild, repair or re-initialise the volume. Then call us on 020 3026 0184.
What a NAS is and how it stores your files
A NAS is a small computer whose only job is to hold disks and share them over the network, so several people can open the same files at once. These units take high-capacity hard drives, so we rarely see one with 500GB of storage or less, and most modern models hold two or more drives arranged as a RAID.
File systems and inodes
Most NAS boxes run a cut-down version of Linux and format their disks with Linux file systems such as ext4, Btrfs or XFS, not the NTFS or APFS your PC or Mac uses. That is why a NAS disk plugged straight into a Windows machine shows up as empty or unformatted. It is not empty. Windows cannot read it, and if it offers to format the disk, say no.
These file systems track files through inodes. An inode is a small record holding a file’s size, dates, permissions and the addresses of the blocks where its contents live. The file’s name sits separately, in a directory entry that points at the inode.
Delete a file, reformat the volume or let the file system become corrupt and those links between name, inode and data are broken. Putting them back together is far more involved than undeleting a file on a Windows or Mac disk, and on a NAS the file system usually sits on top of a RAID layer as well.
RAID inside a NAS
Larger NAS units spread data across several disks as a RAID, a redundant array of independent disks. Depending on the level chosen, that buys speed, protection against a disk failing, or some of each. RAID 1 mirrors two disks. RAID 5 can lose one disk and carry on. RAID 0 has no redundancy at all, so one dead disk takes the whole volume with it.
When an array loses a disk it limps on in a degraded state, and that is when the real damage is usually done. Pull a disk out of a struggling unit and you may find the volume will not mount at all. Leave a degraded array in use and every new file written to it risks overwriting what could have been saved. RAID 0 and RAID 5 are the most exposed. There is more on failed arrays on our RAID data recovery page.
How NAS units fail
The fault we see most is quiet disk degradation. A hard drive starts to wear out, the NAS lights a warning LED, and nobody notices because the box lives in a cupboard or under a desk with its lights hidden. By the time a second disk goes, the array has been running without a safety net for some time.
Heat is the other regular culprit. A NAS shut in a cabinet with no air moving around it slowly cooks its drives. Single-disk units, such as several models in the Western Digital My Cloud range, have no redundancy to begin with, so one failed drive puts everything out of reach until that drive is repaired.
Other causes we are asked to deal with:
- Accidental reformat
- Faulty NAS controller
- Water or fire damage
- Several hard drives failing together
- NAS configuration errors
- Failure after a power surge
- Overheating or an improper shutdown
- Power failure
- Files deleted or overwritten
- Software corruption
- System crash or malfunction
- Virus or malware infection
What we do with a failed NAS
Every job starts with a free consultation and a firm quote. Tell us the make and model, how many drives are inside and what happened just before it stopped working. The more detail, the better. Drives with physical faults are opened only in our ISO Class 5 (Class 100) clean room.
We recover and rebuild whatever was on the volume: emails, documents, photos, music, video. The work is completely confidential, and if the data cannot be recovered there is no charge.
Guide prices
| Job | Guide price |
|---|---|
| Initial consultation | Free |
| NAS, 2TB (1TB + 1TB), one drive to repair | £450 + VAT |
| QNAP or Synology RAID 5 NAS | £650 + VAT |
| RAID 0 | £650 + VAT |
| RAID 5, 6 and 10, depending on the number of drives | £850 + VAT to £1,500 + VAT |
The price we quote is the price we charge. The full list is on our data recovery prices page.
NAS brands we recover data from
We work on NAS units from all the manufacturers below, plus older Apple, HP, Iomega, Linksys and Samsung models. Three brands have guides of their own: Synology, QNAP and Drobo.
NAS manufacturers we cover 16 listed
- Buffalo
- Dell EMC
- D-Link
- G-Technology
- LenovoEMC
- Freecom
- LaCie
- NetApp
- Netgear
- QNAP
- Seagate
- Synology
- Drobo
- Thecus
- PROMISE Technology
- WD (Western Digital)
NAS and RAID units by brand
- Seagate
- Synology
- Freecom
- Western Digital
- QNAP
- PROMISE
- G-Technology
- Buffalo
- LenovoEMC
- LaCie
- NetApp
- NETGEAR Ready
Getting the unit to us
Bring the NAS, with all its disks still in their bays, to 68A North End Road in West Kensington. We also offer free collection and return from your home or office across central and south London, and you can post it to us. If the disks are already out, label each one with the bay it came from. For a shorter summary of the service, see NAS data recovery in Kensington.
Questions people ask
Can I take the disks out of my NAS and read them on a PC?
Almost certainly not. NAS disks use Linux file systems that Windows and macOS cannot read, and in a RAID each disk holds only part of the data. Removing disks or mixing up their order can stop the volume mounting at all. Leave them in the unit and switch it off.
My NAS says the volume is degraded. Can I keep using it?
No. A degraded array has already lost a disk and has little or no protection left. New data written to it can cause permanent file loss, and RAID 0 and RAID 5 are the most at risk. Power the unit down and get in touch before doing anything else.
How much does NAS data recovery cost?
The initial consultation is free. As a guide, a 2TB NAS with one drive to repair is £450 + VAT and a QNAP or Synology RAID 5 NAS is £650 + VAT. You get a firm quote before work starts, and if the data cannot be recovered there is no charge.
Do you recover single-disk units such as the WD My Cloud?
Yes. Single-disk NAS units have no redundancy, so when the drive fails the data is inaccessible until that drive is repaired. Physical repairs are carried out in our ISO Class 5 (Class 100) clean room.
Why did nobody notice the first disk failing?
Because the warning is usually a small LED on a box that lives out of sight in a cupboard or under a desk. Disks degrade gradually, the unit keeps working, and the first anyone knows is when the array finally stops.