Computer does not "recognise device"

Using PhotoRec to recover lost data
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DavidEllis
Posts: 3
Joined: 24 Jun 2014, 14:18

Computer does not "recognise device"

#1 Post by DavidEllis » 24 Jun 2014, 15:14

I have installed the latest version v.14. of photorec and I am transferring all the detected files to a separate ext HDD.
My Computer is a MacBook Pro and I am connected via firewire to the troublesome iomega minimax 1TB ext HDD (Samsung HD 105S1) and transferring the files to a recup dir on a WD HDD via firewire.
I have a few questions:
I cannot see any of my .cr2 files (Canon 7D) but I am seeing two .jpg versions (of different file size) of the same photograph with a thumbnail copy. Does this version of photorec recognise .cr2 files? Can I prevent the duplication of .jpg's?

I have been continuously reading the 1TB HDD for 120 hours and have only scanned nearly 10% of the drives' sectors. The estimated time to completion is 1047 hours and this value is steadily increasing. The realtime readout of the scanned sectors increments by 897 every second and reaches a certain value, this realtime value then resets back to a lower value and the incremental growth resumes until it exceeds the previous maximum, progresses for a few 'scans' and then reverts back to this low value. This "to and fro" behaviour accounts for the incredibly long tedious process of recovering my files. Is this lengthy process to be expected? How can I speed up the file recovery?

The HD quality video that has been recovered has been severely reduced in quality both resolution and timing. Some video has become a series of jpg 'stills'. Is this to be expected?
I would be grateful if you could address my concerns with a solution.
May I say that I am amazed that the PhotoRec file recovery process is miraculous, considering certain "experts" have condemned the HDD to the 'bin' on two occasions.

Yours sincerely,

Dave Ellis

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Fiona
Posts: 2836
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Computer does not "recognise device"

#2 Post by Fiona » 25 Jun 2014, 06:37

Cr2 might be a part of the tif file family?
You'll find it here under multimedia:
http://www.cgsecurity.org/wiki/File_For ... y_PhotoRec
You can use photorec / FileOpt and pressing s to deselect all file types.
Please select only these file types where you'd like to recover and try it again.
It avoids to recover unnecessary file types.
For example tif which should recover cr2-files also.
If PhotoRec still doesn't find any image, you can contact christophe grenier describing your problem:
http://www.cgsecurity.org/wiki/PhotoRec#Problems.3F
Including a file as an example or pattern might help.
PhotoRec allows to add your own extension to recover unsupported file types using photorec.
Info:
http://www.cgsecurity.org/wiki/Add_your ... o_PhotoRec
Currently I'm testing it.

Fiona

DavidEllis
Posts: 3
Joined: 24 Jun 2014, 14:18

Re: Computer does not "recognise device"

#3 Post by DavidEllis » 25 Jun 2014, 11:21

Thank you Fiona for your quick response.

I would like to return to the question of the missing/converted .CR2 files: When I take a photograph using my Canon 7D camera a high quality RAW file and a high quality jpeg file are created. The file name is the same; for example IMG_7079 and two files result having different extensions and different file sizes: e.g. IMG_7079.cr2 and IMG_7079.jpg. The RAW (.cr2) file is usually 24MB and the compressed jpeg file is typically 6MB.

The recovered files of the same image from the PhotoRec process consists of three jpeg files - typically 7MB, 6MB and 5KB (for the thumbnail image). A TIFF(.cr2) file of 24MB is not produced. I can only guess that one of these jpg files is the missing RAW file which has undergone conversion in recovery.

I would appreciate your opinion on the matter.

If I have to contact Christophe with specimen examples of a file set for an image. Could you be more explicit as to what files I should send him? It will be difficult sending him the original .cr2 file as the only means I have, at my disposal, is using the PhotoRec recovery process. The original RAW file being inaccessible on the hard drive.

Thanks you once again.

Dave

User avatar
Fiona
Posts: 2836
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Computer does not "recognise device"

#4 Post by Fiona » 25 Jun 2014, 20:10

I'll have a look why cr2 files are not recoverd.

Fiona

DavidEllis
Posts: 3
Joined: 24 Jun 2014, 14:18

Re: Computer does not "recognise device"

#5 Post by DavidEllis » 26 Jun 2014, 10:39

Thank you Fiona.

However, I switched on the HDD and computer this morning and the PhotoRec recovery failed to continue with finding files. Instead, errors resulted reading all the remaining sectors. I attempted to start afresh with a new Recup_dir folder with the search producing errors reading all sectors. I have attached the fault file:report.xml Carve Report PhotoRec 7.0-WIP GCC 4.0 2014-06-17T18:21:04 Darwin 13.2.0 Darwin Kernel Version 13.2.0: Thu Apr 17 23:03:13 PDT 2014; root:xnu-2422.100.13~1/RELEASE_X86_64 David-elliss-MacBook-Pro.local x86_64 0 2014-06-26T08:44:51+0100 /dev/rdisk3 512 1000204886016.

Am I using the most uptodate version of PhotoRec 7.0?

Thank you for your continued support.

Dave Ellis

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