One thing to know first
Don't let anything repair it. That prompt is the danger, not the fault.
The device is visible, which means the hardware is talking. What has failed is the filesystem, the index describing where each file begins and ends. Your files are almost always still sitting on the media untouched. The damage in this scenario is nearly always self-inflicted afterwards: chkdsk, Disk Utility's First Aid, or a format writes new structures over the damaged ones, and in doing so overwrites the information a recovery would have used to reassemble your files.
Often fixable yourself
NAS shows up but won't open
A NAS in this state is very often something you can resolve yourself, at no cost, and this page tells you how before it tells you anything about us. Where that doesn't work, the rest explains what the fault usually is and what recovery involves.
What this usually turns out to be
There are two independent layers here and knowing which one has failed decides everything. Underneath is the array, the arrangement that binds the member disks into one logical device. On top of that sits a filesystem. If the array assembles and the filesystem is corrupt, this is an ordinary and usually very recoverable filesystem repair on a large volume. If the array is not assembling, the filesystem above it cannot be assessed at all, and the job is reconstructing the arrangement first. The unit's own interface tends to present both as a single unhappy volume.
An array is a set of member disks plus the arrangement that binds them. Losing the arrangement loses the data even when every disk is healthy.
Corrupt filesystem metadatabetter news
The master file table or catalogue is damaged. The file content is intact and reachable; the map to it is not.
Interrupted write or unsafe removalbetter news
Power lost or the device pulled mid-write, leaving the filesystem in an inconsistent state. Usually very recoverable.
Bad sectors in the metadata region
The drive is degrading and the unreadable areas happen to be the ones holding the index. This case does have a clock on it.
Encryption without the key
BitLocker, FileVault or a NAS volume password. The data is intact but mathematically unreachable without the key or password.
What to check first on a NAS
- Read the storage manager and separate the two layers: does it report the array or storage pool as present, and the volume on top of it as damaged, or does it not see the array at all?
- Record how many members it considers healthy, and their order, and photograph the bays before touching anything.
- Check whether snapshots exist. Many units keep them by default and they are frequently the whole answer.
What not to do
Do not accept an offer to repair the filesystem, and do not run the unit's own file system check on a volume whose array is degraded. Repairing a filesystem that sits on an incompletely assembled array writes corrections calculated from the wrong data, and that damage is applied across the array rather than to one disk.
Try this before you pay anyone
Find out which layer failed, and check for a snapshot first
- Read the unit's storage manager and separate the two layers: is the array or storage pool present with a damaged volume on top, or is the array not assembling at all?
- Check the snapshot list. Many units take them by default, they sit below the volume, and browsing an earlier one is frequently the entire answer at no cost.
- Record how many members the unit considers healthy and in what order, and photograph the bays before moving anything.
Do not run the unit's own filesystem check or repair on a volume whose array is degraded, and do not run carving software against individual member disks. A repair calculated from an incompletely assembled array writes its corrections across every member, which turns a recoverable array into a damaged one.
How recoverable this is
Usually good, and often very good, because the media is intact and the fault is in the description of the data rather than in the data. The main determinant is not the original fault at all. It is whether a repair tool has already been run. Cases that arrive untouched tend to go well. Cases where chkdsk has already rewritten the structures are meaningfully harder, and sometimes that is what decides the outcome.
What moves it, for your device specifically:
- Whether a repair, format or chkdsk has already been run against it
- Whether the underlying media is healthy or has bad sectors
- Whether the volume is encrypted, and whether the key or password is available
- How much has been written to the device since the problem appeared
We will not give you a percentage for your device, and you should be wary of anyone who does. Nobody can know what is recoverable until the media has been imaged and read. What is above describes this class of failure; your drive gets its own answer after an assessment, in writing, at no cost.
What it costs
from $690
RAID, NAS and servers
Arrays rebuilt from the member disks rather than trusting the controller that failed. Any filesystem, including ext4, Btrfs, ZFS and VMFS.
What moves a job within its band: capacity, how much of the media is unstable, whether the filesystem is encrypted, and how much of the drive has to be read before the files you need are reachable. You get one fixed figure after the assessment and it does not move afterwards. If we can’t recover what matters to you, there is no recovery fee.
Other faults on a NAS
Detected but unreadable on other devices
Next step
Tell us what failed.
Free assessment. Fixed quote before recovery starts. No recovery, no fee. Sydney drop-off or Australia-wide by tracked post.