Read this before you do anything else
Switch it off immediately. This is the worst noise a drive makes.
Grinding means physical contact between the head assembly and the platter surface while the platters are turning. It is the one noise that is actively destroying the recorded surface as you listen to it. Not risking damage, causing it. Material removed from a platter is gone, and no lab recovers what is no longer physically there. Of every symptom on this site, this is the one where the seconds genuinely count.
Emergency
NAS grinding
If your NAS is making a grinding noise, the most useful thing on this page is above this paragraph, and it is free. What follows is what the fault usually turns out to be, how recoverable this class of failure is, and what it would cost, including the cases we would tell you to take elsewhere.
What this usually turns out to be
A NAS chassis contains at least one fan and often two, sitting directly behind the drive bays, and those fans are the commonest source of a grinding noise from a unit that is otherwise working perfectly. If the drives are healthy and the volume is online, suspect the fan first. If it genuinely is a disk, the array's own protection is what puts you at risk next: the unit will want to rebuild, and a rebuild reads every surviving disk from end to end at exactly the moment you least want that.
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.
Head crash
The heads have come down onto the platters and are scraping the magnetic surface away as the stack spins.
Debris circulating inside the drive
Material shed by a previous failure is being dragged between head and platter, scoring the surface on every rotation.
Collapsed bearing
The platter stack is no longer turning true, bringing the surface into the head's path.
What to check first on a NAS
- Check the unit's fan speed and temperature readings in its own dashboard, and check whether it is reporting any disk as failed. A grinding noise with every member healthy is very likely the fan.
- Put your ear to the back of the chassis and then to the front of the bays. A fan is loudest at the exhaust, a disk at its own bay.
- If a disk is implicated, label all disks with their bay order before touching anything.
What not to do
Do not start a rebuild or insert a replacement disk to make the warning go away. And do not run a disk scrub or health check across the array to identify the culprit, because that reads every disk in the unit and is the single heaviest thing you can ask of a set of aging drives.
How recoverable this is
The narrowest and least optimistic of any symptom here, and the fair framing is that outcome is decided largely by how long it ran making that noise. Where scoring is confined to regions your files do not occupy, recovery of the rest is realistic. Where it has cut through the area holding them, that part is not recoverable by anyone, and you should be sceptical of a lab that says otherwise.
What moves it, for your device specifically:
- How long it was left running while grinding, which is the single biggest factor
- Which regions of the surface were scored, and whether your files live there
- Whether debris has contaminated otherwise intact surfaces
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
Assessed free, then referred at no charge
Cleanroom mechanical work
Clicking, seized or head-crashed drives need internal mechanical work in a controlled environment. We don't have one, so we assess it, tell you what we found in writing, and refer it on. That referral costs you nothing here.
Nothing is charged until you have seen a fixed quote for your actual device and agreed to it, and the assessment that produces it is free.
Other faults on a NAS
Grinding or scraping 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.