Recovered Files Unreadable

Using PhotoRec to recover lost data
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Naga
Posts: 2
Joined: 24 Oct 2020, 10:20

Recovered Files Unreadable

#1 Post by Naga »

Three weeks ago, I noticed that my external drive suddenly slowed to a crawl. Ran CHKDSK and sure enough there were bad sectors. Ran CHKDSK /f /r after that but it took ages and stopped after more than a day. I narrowed down the affected files to a folder containing over 400+ images and videos.

I came across TestDisk and it was a life-saver. I managed to copy all the contents of the folder to another drive. However, I noticed that about 100 of them were corrupted. Some of the images were showing the correct previews but the full images were just flat gray. The other images and videos were not even showing any previews and can't be opened.

I'm returning the drive for an exchange but before I do that, I'd like to give it a final go to recover the 100 corrupted files. Is this possible or are the files lost for good?

Many thanks.
recuperation
Posts: 3026
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Recovered Files Unreadable

#2 Post by recuperation »

Rerunning Testdisk won't bring back the missing files.
You could run Photorec.

Both programs are not designed to handle unreadable sectors.
I don't know if Testdisk stops reading a file if a read error occurs.
Please duplicate your drive using ddrescue to have a copy that does not produce read errors.
Using the duplicated drive would prevent Testdisk from stopping even though the unreadable sectors could not be read.
That could increase the recovery outcome of Testdisk.
As you narrowed down the affected files being in one folder you would rerun Testdisk only trying to copy the files in that particular folder again.
Photorec might find some remains of the files you could not recover.
Naga
Posts: 2
Joined: 24 Oct 2020, 10:20

Re: Recovered Files Unreadable

#3 Post by Naga »

TestDisk didn't produce any error when copying the corrupted files. It happily copied them over just like the other good files with no noticeable delay. I'm not sure if TestDisk skipped the bad sectors but it managed to copy every single file without stalling. Prior to discovering Testdisk, I tried the normal Windows copy/paste and Robocopy but most copying stalled even when good files were being copied.
recuperation
Posts: 3026
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Recovered Files Unreadable

#4 Post by recuperation »

Naga wrote: 24 Oct 2020, 11:18 TestDisk didn't produce any error when copying the corrupted files. It happily copied them over just like the other good files with no noticeable delay. I'm not sure if TestDisk skipped the bad sectors but it managed to copy every single file without stalling. Prior to discovering Testdisk, I tried the normal Windows copy/paste and Robocopy but most copying stalled even when good files were being copied.
Thank you for the feedback. You might try Photorec nevertheless or even a commercial software.
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