Recovery only undamaged files

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michal

Recovery only undamaged files

Post by michal » Wed Aug 19, 2020 12:01 pm

Hi guys,

R-Studio shows a list of pdf files I have. Some files are marked with blue rectangle and some don't. Those that are seem undamaged and those that aren't - damaged. Is it always the case? How do I recover only undamaged files?

Thanks

Alt
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Re: Recovery only undamaged files

Post by Alt » Fri Aug 21, 2020 12:59 pm

The only way to tell damaged and undamaged files for certain is to recover and test. The Recovery chances column on the Content panel may be of some help.

abolibibelot
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Re: Recovery only undamaged files

Post by abolibibelot » Fri Sep 18, 2020 2:14 am

The blue square / rectangle, if I'm not mistaken, means that the file was also detected by the file signature search method and therefore appears as a link under “Extra found files” (right-clicking on it should show a “Links” context menu, then clicking on the file name directly leads to the linked file). Indeed, in most cases, if a file of a type that was selected for signature search during the scan appears in “Root” without the blue thingy, the file is probably corrupted / overwritten (at least its header – even a single overwritten cluster at the beginning renders the file undetectable, and generally unreadable, unless it's a text file or something similar).
But it can also happen that a file of a supposed type, for instance PDF, appears with a link to “Extra found files” as another file type (for instance it's been replaced by the beginning of a MP4 video file, and the PDF appears in the “MP4” virtual directory under “Extra found files”), and is therefore no longer recoverable as a PDF. All the files identified in “Root” that do appear in the “Adobe PDF document” directory, however, should be readable (unless they have been partially overwritten at another location than the header and are too damaged to be opened).

Alt
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Posts: 2630
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Re: Recovery only undamaged files

Post by Alt » Fri Sep 18, 2020 9:20 am

abolibibelot wrote:
Fri Sep 18, 2020 2:14 am
The blue square / rectangle, if I'm not mistaken, means that the file was also detected by the file signature search method and therefore appears as a link under “Extra found files” (right-clicking on it should show a “Links” context menu, then clicking on the file name directly leads to the linked file). Indeed, in most cases, if a file of a type that was selected for signature search during the scan appears in “Root” without the blue thingy, the file is probably corrupted / overwritten (at least its header – even a single overwritten cluster at the beginning renders the file undetectable, and generally unreadable, unless it's a text file or something similar).
But it can also happen that a file of a supposed type, for instance PDF, appears with a link to “Extra found files” as another file type (for instance it's been replaced by the beginning of a MP4 video file, and the PDF appears in the “MP4” virtual directory under “Extra found files”), and is therefore no longer recoverable as a PDF. All the files identified in “Root” that do appear in the “Adobe PDF document” directory, however, should be readable (unless they have been partially overwritten at another location than the header and are too damaged to be opened).
I'd add that "file signature search" requires a complete disk scan. And you may look at file integrity by right-clicking the file and selecting Get Info on the shortcut menu.

abolibibelot
Posts: 38
Joined: Sun Jan 31, 2016 5:45 pm
Location: France

Re: Recovery only undamaged files

Post by abolibibelot » Fri Sep 18, 2020 8:04 pm

I'd add that "file signature search" requires a complete disk scan. And you may look at file integrity by right-clicking the file and selecting Get Info on the shortcut menu.
In my experience so far the “Recovery chances” column doesn't show much useful information, as I explained here. Surprisingly, Recuva, a free software which hasn't been updated since 2016, is much more reliable in that regard.

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