Hermanland Weblog

I name my photo file or video file as 110108_GF1_1000117 where 110109 is the date when the photo or video was taken, GF1 is the camera or videocam model and 1000117 is the sequence number of the original file. This will give more likely an unique file name within all my collection. Despite the files may be kept in separate folders, name crash may still happen when they will be cached in other devices or uploaded to some online album.  Hence, unique naming convention is desirable.  If the meta date e.g. EXIF is erased by mistake, I still know at least the date when the photo was taken.  I still keep the original sequence number so that I can relate the file to the original, especially when the photo was taken by the other and given to me.  In that case, the file name is 110108_OTHER_1000117.  For music file or movie file, I use the song name or the movie name.  Hence, the file name may not be in English e.g. in Chinese or Japanese.

How can I ensure my photo files loaded into hard disk few years ago are still in good health without any data corruption.  The storage material could be aging to a point when some data is no longer kept in proper shape.  Manually inspecting 1000+ photo will not be healthy to my eyes for sure.  I let the computer to do it for me by comparing the photo files with their checksum.  Therefore, I only need to do manual inspection once after creating the checksum and freezing it.  I use a tool called FileVerifier which creates a FVA checksum text file.  The file contains multiple lines – one line for one file name and its checksum.  The tool can automatically compare the files with their checksum and highlight those which don’t match. Most importantly, I can just select those un-matched files and re-compute their checksum and update to the checksum file while leaving the matched files checksum untouched.  To be prudent, I create a new checksum file rather than update the existing checksum file. That way, I can compare the new checksum file with the old one using tool e.g. ExamDiff. The un-matched files also need to be manual inspected of course.  Similar health check is done on optical media e.g. DVD disk.