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PhotoRec on Linux LVM2 disks - EXIF info is lost

Posted: 14 Aug 2018, 17:36
by roelvdh
My Linux LVM2 Volume Group failed when 2 out of 4 disks returned an I/O error. File system is XFS, but it seems to be unrepairable, superblock cannot be found anymore.
I decided to use Photorec on each of the 4 standalone disks, the 2 good ones directly, the failing 2 by first running ddrescue. As many of the files on the LVM contain EXIF info, I was hoping to recover the file structure by using EXIF date info and original File ID.
PhotoRec has done a perfect job on the first disk, recovering many files. PhotoRec is now running on the second drive.
However, when I inspected the recovered files with ExifTool I noticed the important part of the original EXIF data was replaced by PhotoRec: the date info has been changed into the actual recovery date and the original FileID was replaced by the PhotoRec filename. This way I cannot restructure the files.
Would there be a possibility to run PhotoRec while preserving these EXIF tags (or did I miss something when reading through the documentation)?
And a more basic question: Is my approach of recovering data from a failed LVM the most appropriate one?
Thanks in advance for any help.

Re: PhotoRec on Linux LVM2 disks - EXIF info is lost

Posted: 15 Aug 2018, 07:29
by cgrenier
PhotoRec doesn't modify the EXIF information. Run "exiftool -v f*.jpg" to check the APP1 information.

It's recommended to
- clone each damaged disks using ddrescue
- remove the damaged disks
- reenable the Logical Group.

Re: PhotoRec on Linux LVM2 disks - EXIF info is lost

Posted: 15 Aug 2018, 18:56
by roelvdh
Merci beaucoup. So, this should be an LVM issue, PhotoRec is possibly not even necessary? I have been in such a situation before and failed to reenable the new disk replacing the failing disk. I assume I need to reset the UUID of the failing disk onto the new one, but as I would hate losing it all again I would appreciate some help, even though this is a PhotoRec forum, not LVM. Thanks again in advance. I still like PhotoRec, even though I may have used it in vain.

Re: PhotoRec on Linux LVM2 disks - EXIF info is lost

Posted: 16 Aug 2018, 14:33
by roelvdh
vgcfgrestore does it