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My external hard disk often starts making an irritating scraping/grinding sound. It stops if I do something that causes disk activity on it. But then, after 3 minutes or so, it starts again. It's very annoying. Is there a way to disable it?

It's a Western Digital WD 10EAVS.

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Can you power up the drive without it connected to a computer and see if it makes the noise? – NitroxDM May 27 '10 at 20:27
up vote 4 down vote accepted


I have 4 WD Elements (external) drives. 2 x 1TB EADS 1 x 1TB EAVS 1 x 650Gb AAKS

I've been plagued by this noise since DAY 1:

1) It happens when the drives are IDLE and not necessarily connected to any host (discard ALL OS related issues).

2) It STOPS as soon as the drive is accessed OR put in Standby (ex: with WD Spindown Utility).

3) It seems to affect the MORE EMPTY drives more often!!


1) Some or ALL WD drives use PWL

2) Preemptive Wear Leveling (PWL) The drive arm frequently sweeps across the disk to reduce uneven wear on the drive surface common to audio video streaming applications. WD AV SATA and PATA drives are ideal for PVR/DVR, DVD recorders, surveillance video recorders, and other video streaming applications (see:

3) WD states that WD AV drives are "GREEN drives"... need to say more?


1) PWL is a firmware supported feature that kicks in when the drive is not BUSY (idle)

2) The fact that the noise if much more noticed on drives that are not full complies with PWL "Static wear leveling" mode (see: wikipedia's Wear leveling)

3) ALL WD drives have PWL to protect our data, because there should be NO REASON to remove this feature (it will increase the reliability of the drives, thus, increasing WD reputation)

4) THE ONLY reason WD does not come public with this is because they announce it to be a feature available to specific drives. Is it??? I don't think so. (need to point everyday examples of firmware functionality that gets removed or disabled on capable but "cheaper to the consumer" hardware??? It's only logic!)

Bottom Line: I'm convinced that this is a FRIENDLY healthy noise. NOW... should we start worrying if the noise goes away??? :-))

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Lately I haven't been bothered by the noise anymore because I usually have uTorrent running in the background, which prevents the maintenance mode from kicking in. Yet another reason to be a pirate :) – StackedCrooked Jan 29 '11 at 5:06

Assuming that sound is the normal sound of disk activity, one possibility is your system may be running a process like File Indexing Service which may be the reason of sound. Those services are generally activated when computer is idle and stops on usage. If this is the case, you should disable File Indexing for the external HD.

Another possibility is your external hard disk is functioning improperly and I strictly recommend you to back up your important data ASAP. Since I did not hear the sound, these are my estimates at the moment.

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I think it's a maintance job, not from Windows but from the device driver itself. I think so because the sound is sharper than that of normal disk activity (like defragmentation). – StackedCrooked May 27 '10 at 18:15
The sounds continue after the drive is ejected from my Mac, so it can't be a high level service. My red WD drives don't make the noise. – James Roth Oct 7 '14 at 14:32

The fact that it happens only when idle makes it seem like it must be some sort of indexing/defragging service. To test, you could see if it makes the same sound when copying many small files to or from the drive. This makes the read/write head move between the data area and the file table a lot which, on most drives, makes a grinding noise. If this noise and the "idle noise" are not similar, it may be a defective drive that is damaging itself when it spins down.

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Is there a fan? If so is it clogged with dust? The fan man be slowing down on demand. Rare but possible.

Otherwise, I assume it's due to the drive spinning down as Puddingfox said.

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If you ever hear scraping-clicking-anything that you have not heard before, and you know the sound it should make because you use your computer EVERY DAY- copy it off and back it up.

Doesn't matter if the drive is 1 day old, just do it.

You are very lucky that its making a sound and STILL working. And I believe that you must know the difference between HDD activity sounds and BAD sounds, if it sounds like the scrapping of metal then just bin it while you can get your data off.

Warm Regards


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It's an activity sound. It always starts after about 3 minutes of being idle. (English is not my mother tongue so I may have used the wrong wording in describing the sound..) – StackedCrooked Jul 26 '10 at 18:06

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