I'm currently transferring my Lightroom catalog from my laptop to my new desktop PC. I decided to copy both the catalog file itself and the preview files (folder
Lightroom 3 Catalog Previews.lrdata). I've been really astonished about its size and the number of files it contains: it's nearly 3 GB and contains over 40.000 files for a catalog that contains about 8.000 photos. In the catalog options I have chosen
Automatically Discard 1:1 Previews > After 30 Days, so I would expect LR to delete previews that haven't been needed for 30 days. Still, the folder contains files that are over 2 years old and haven't been accessed for over 2 years.
I have well noticed the following from the Adobe site:
Note, however, that the file that contains the previews, the [Catalog name] Previews.lrdata file can grow large if you have the option to delete previews set to Never or 30 days.
But this does not explain, why the previews folder contains files with "old" access times.
Therefore my question: why does the preview folder grow so big and how can I prevent this in the future?