My CUPS server has bad, obsolete data in /var/cups/cache. I could just blow away all the files, but I'd like to know if there is a "correct" way to clear the CUPS cache. Man pages and Google have not yielded an answer.
This long thread suggests that /var/spool/cups contains completed print jobs while /var/spool/cups/tmp contains in-progress jobs. One post to that thread suggests running
If you really need to delete cache files in /var/cache/cups, you will probably need to use the manual method.