Doubt bad sectors HDDs

General Discussion
1

On HDDs, do bad sectors (badblocks) contaminate good sectors? If I copied files to an HDD and then tested for data corruption and there was no corruption, when storing the HDD in a drawer or during use, does the bad sector automatically contaminate and transform the good sector of the files into a bad sector, corrupting the files?

2

A bad sector does not “contaminate” a good one, but sectors can go bad over time.

3

  1. If the sectors get worse over time, will I lose the files and will these files become corrupted because if the sectors get worse they transform good sectors into bad sectors and the files are in the good sectors?

  2. I have a WD 2.5" HDD and I have been using it for many years with the yellow health alert in crystaldiskinfo and these bad sectors have not increased, it has reallocated sectors count

  3. How many situations are there that the bad sectors will increase or not increase?

4

Yes. That’s one of the reasons you use redundancy and back up your data.

Virtually all of them if you run the drive long enough–unless something else kills it first.

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5

So the good sector turns into a bad sector? And the good sector where the files are will be corrupted?

6

Files are stored on the HDD with some kind of ECC built in; HDDs are divided into sectors which host the data, plus a small reserve of spare sectors; when the HDD detects[1] part of a sector is going bad, it re-allocates it to a spare sector.
Eventually, the spare sectors get all used and the drive is no longer able to cope with failing sectors.

A failed sector does not corrupt data per se, but is generally not able to properly function anymore (hence damaging/corrupting files or, more likely, part of files stored in that sector).

This is a very generic explaination: point is, lots of reallocated sectors means danger. We use multiple drives, as well as hardware and software RAID, for this reason.

If you want more information about this incredibily interesting topic, I suggest reading How hard disk drive work? How are data accessed by an OS? | by Ishan Rijal | Medium.

  1. aka encounters a read/write error ↩︎

7

  1. A quick scan from Victoria does not give any indication that the HDD is in good or bad condition and the alert recommends a full scan?

  2. Is it better to connect an external HDD to the front USB 2.0 or 3.0 port of the PC without any extension cable or is it better to use a USB 3.0 extension cable from Ugreen to connect to the rear USB 3.0 port of the motherboard and to the external HDD?
    https://a-static.mlcdn.com.br/450x450/cabo-extensor-usb-3-0-ugreen-macho-femea-extensao-2-metros/comemoria/4308/edf5be54aa4f359ede83dc8ae0d8c383.jpeg

  3. I have a 2.5" Seagate Barracuda HDD, is the Seatools 5 software with Generic Long Test a good software and a good test for this HDD or not?

8
  1. How to Test Your Hard Drive Health: Windows, Mac OS, Linux
  2. Generally it’s better to not use extension cables; using the case USB ports should not be an issue.
  3. Usually, the manufacturer’s software is a solid choice… but not a mandatory one.
DO NOTE

These are replies for general use, NOT NAS use.

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