[galaxy-dev] unable to purge deleted datasets

Hi all,Using two commands below, I am unable to purge deleted datasets (from a local instance of galaxy installed on ubuntu). I have deleted some datasets from the history panel and I want to purge only datasets not the history itself. commands: 1. python scripts/cleanup_datasets/cleanup_datasets.py universe_wsgi.ini -d 0 -6 -r 2. python scripts/cleanup_datasets/cleanup_datasets.py universe_wsgi.ini -d 0 -3 -r results:Purged 0 datasetsFreed disk space: 0 I can't figure out what's wrong. Maybe a privilege problem or something else?? Any help would be most appreciated.