So I pulled this hard drive out of a unit that was un-formated on of no where and re-formated it just fine in windows. Decided to run some test on it and got these errors.

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Reallocated Sector Count

Reallocated Event Count

Current Pending Sector

Ran a Disk Check: with no errors...

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Can these errors be fixed? I've formated the drive 3 times now, and each time it was successful. I can copy stuff to the drive just fine.

  • 2
    No HDD is going to be perfect. That is just the HDD marking sectors that are bad and working around them. If the count isn't changing and you're not experiencing any negative issues other than this warning, I'd say your fine. That's not to say it will last forever, everything ages and dies. Jan 22, 2015 at 22:10
  • Right, so is it possible to fix the errors? how long does a drive in this condition typically last? Jan 22, 2015 at 22:11
  • They are being "fixed" they are being reallocated, but that is quite a few, and you also have some more (pending). The disks hardware attempts to fix and hide these issues, so the OS chkdsk is not seeing them (yet). Agrees with the above, if it is not getting more and more, but that is pretty bad, and most people seeing that would not bother with it, and it is likely to have more again. You copy stuff to it but another testing would be to do a full byte by byte compare of the copied files too. There are low possibilites that something else is wackey (cause) like the power is dirty.
    – Psycogeek
    Jan 22, 2015 at 23:05
  • 1
    A lot of reallocated and pending sectors could indicate the the drive is starting to fail. But it might as well continue working for a few more years. You can download WD testing tool – WD DLG products.wdc.com/support/kb.ashx?id=xQZNg2 and run the short and extended tests. If the HDD fails any of those diagnostics and if it's still in warranty you can RMA the drive. Jan 23, 2015 at 15:34

2 Answers 2


A HDD only detects faulty sectors when it tries to read from it but fails. Then it adds the sector to the pending sector count. Which will reallocate it to somewhere else as soon as you try to write to this sector the next time. (reallocated sector count)

Why did the read fail? Either the writing failed (and was not noticed since HDDs just write and assume it was successful) or the reading simply does not work for whatever reasons. The thing is, to be sure that your HDD is okay you need to write to every sector and then read every sector.

If after reading every sector the pending sector count has increased, you know that something is still broken.

I would suggest a tool like http://hddscan.com/ Use it to write and read every sector (preferably several times) to ensure your drive is okay (i.e., the yellow values do not change). Also the pending sector count should be zero.

Nevertheless you should probably backup and replace the drive. ,

After their first reallocation, drives are over 14 times more likely to fail within 60 days than drives without reallocation counts, making the critical threshold for this parameter also one.

Source: Failure Trends in a Large Disk Drive Population


In the past, I have used a large number of mechanical WD hard drives and most of them started to show such warnings 3-6 months before a failure. My recommendation is to backup data and replace the hard drive.

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