3 Replies Latest reply on May 18, 2016 9:20 AM by johnrellis

    What is the effect of overwriting disk metadata with metadata from catalog?

    dan_mclean

      I have a large collection of images on both internal and external disks which I am consolidating onto one external and one internal drive. File location may have nothing to do with my question. I will frequently see images tagged with either the "metadata changed by an external application" which have not been processed in another application. I also have images tagged "error writing metadata." Retry fails and you have the choice of overwriting the metadata.

       

      My question is whether to use the metadata from disk or from the catalog. I don't want to lose capture data, Lightroom metadata written on import or keywords. I'd like an explanation of what causes these errors and the effect of choosing the disk data or the catalog data.

       

      Thanks.

        • 1. Re: What is the effect of overwriting disk metadata with metadata from catalog?
          johnrellis Most Valuable Participant

          LR stores its understanding of a photo's metadata in the catalog -- the catalog is the "truth".  The metadata status is supposed to indicate whether what's in the catalog is newer than what's stored in the file and whether an external application may have modified the file's metadata after LR read it into the catalog (a conflict). 


          Over the years, LR has had significant problems showing the correct metadata status for a photo. It was much worse in older versions, but I've seen a few reports of incorrect status in LR 6 / CC 2015, and I've encountered a couple of instances myself.


          As long as you're confident that you haven't run external applications that have changed a file's metadata, you can be confident that what's in your catalog is "truth" and ignore status indicators of conflict.  You can freely do Metadata > Save Metadata To File to write what's in the catalog back to the files and often clear the incorrect status.  Anecdotally, it seems that setting the option Catalog Settings > Metadata > Automatically Write Changes Into XMP reduces or eliminates incorrect status indicators.


          However, I wouldn't ignore "error writing metadata".  While you can be confident that the metadata in the LR catalog remains the "truth", that error suggests there is a problem with your file system -- incorrect permissions or a flaky disk.   If the error occurs repeatedly when you do Metadata > Save Metadata To File, that suggests a permissions problem or a permanently corrupted disk (check your backups!). If the problem occurs intermittently, that suggests a flaky disk.

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          • 2. Re: What is the effect of overwriting disk metadata with metadata from catalog?
            Mark_A

            So is the metadata status check not to be trusted?

            I also have noticed inconsistencies with it.

            Sometimes I need to read my images' metadata externally, with a script. Sometimes I also write on the IPTC metadata with another script. I do this on only JPEG, TIFF and PNG files. But now I see that all my videos are flagged as changed on disk. The problem is, I haven't written anything on them. I don't even know how to write metadata on video.

             

            Metadata status search - unstable feature?

            • 3. Re: What is the effect of overwriting disk metadata with metadata from catalog?
              johnrellis Most Valuable Participant
              Metadata status search - unstable feature?

              The metadata status is not always consistent.  If it indicates that metadata has been written to disk, you can believe it. But if it shows that the metadata on disk is newer, or if it shows a conflict, that may or may not be correct.