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My one of the HDDs got lot of bad sectors. Thus it was responding very slow. I used HDDRegenerator and fixed/marked them.

Now I am able to use data properly. Sometimes I feel that files take long time in loading. So I copy them on another HDD before use. (like to watch mov etc)

My question is; is it safe to copy data from hard disk having bad sector to another bad sector free HDD in daily usage?

Somewhere I read that copying data from HDD having bad sector, can copy bad sector too and may corrupt health HDD.

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Somewhere I read that copying data from HDD having bad sector, can copy bad sector too and may corrupt health HDD.

No, this is not true. However, you can end up with corrupted data, since the data wasn't recoverable from the original drive.

When a drive has a bad sector, the drive firmware uses various tricks to try to recover the data (flying closer to the disk, increasing the tolerance on the signal detection system, simply trying to read it a dozen times and hoping one of them works, etc), only if all of that fails... the drive reports an error back to the operating system.

What happens now depends on which knobs the operating system has turned. The drive typically tries to blacklist that sector and returns some pregenerated data (usually 0's, although this is configurable) back to the computer. For subsequent writes to that location, the drive internally remaps those sector addresses (LBAs) to a special section of the drive dedicated to such things.

Most hard drive errors are never seen by the user, since modern drives are fairly good at recovering data on their own. Some types of drive errors, such as bumps on the surface of the disk or damaged heads... have a tendancy of "spreading" across the drive. Causing you to lose more and more data as time goes on. If you are seeing errors persistently, you should be getting rid of that disk quickly... since you may have filled that section of the drive used for overprovisioning, or simply have ALOT of errors.

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thanks.. Now I am worryless. I am already expecting that I have lost the data on that corrupted disk. However I am using it from last 1 year at least when I observed bad sector on it. –  articlestack Jan 11 '13 at 9:37
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You can't copy bad sectors of a hard drive and create bad sectors on the new drive.

This can also be an issue regardless of poor or high HDD quality/condition. You'll need to verify the integrity of the files after you copy them (a quick way is to compare file size after compressing both files if you only have a few files, but there are 3rd party tools that exist for comparing files).

Or, you can do it via command prompt

DOS: "fc (file1) (file2) /B"
Linux: "diff (file1) (file2)"

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1- HDDRegenerator use special magnetic fields (Actually by reading or writing continuously ...) to recover magnetic bad sectors and no all bad sector types. And in my experience most of bad sectors that recovers by HDDRegenerator will return after few usage. So try to backup your data as ASAP.

2- If you can copy data from HDD with bad sectors to new HDD means there is no bad sector under your file, if your file is on a bad sector you cannot copy it with regular tools like Linux cp or Windows copy.

3- Even if you could copy files that written on a bad sectors with special tools do it, it is safe and will not corrupt your destination HDD. It is not recommended for applications and important data though. But OK with musics and Video files in most of the times.

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Nonsense: software cannot create "special magnetic fields". This is controlled purely by the HDD itself. The PC software has no idea how the magnetic fields of the disk are laid out. –  MSalters Jan 10 '13 at 13:57
    
@MSalters You are completely true, software cannot do more than requesting for read or write and HDD hardware controller will manage head and magnetic fields but I see how HDDRegenerator fix the bad sectors. I used "special magnetic fields" to emphasize the software power! It do something more than regular read, write or format. –  ImanGh Jan 10 '13 at 17:50
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Your danger is two-fold:

  1. Some of the data you copy may contain "garbage", because it was not properly recovered.
  2. Eventually that drive is going to fail permanently -- you need to get any valuable data off it and stop using it.
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