Lightroom temp files

Lightroom stores its previews in '.lrdata' folders. You can turn on an option telling lightroom to delete previews after 30days. I however use a lightroom catalogue for each shoot which means some catalouge are not opened for a really long time so the previews never get deleted.

to find the files and the space they take you can just run these commands.
$ cd ~/Pictures
$ find . -iname "*.lrdata" | xargs -I{} du -sh {}

To Remove the files
$ cd ~/Pictures
$ find . -iname "*.lrdata" | xargs -I{} rm -r {}

I worte a small ruby script to help me do this:
lightroom_remove_previews.rb.

It has a hradcoded path to my Pictures folder so you would have to modify that. When calling the script it has 2 main options, --report and --remove, which call the the two main commands described above.