**clean Fedora**
====== /var/cache/PackageKit/ ======
<code>sudo pkcon refresh force -c -1</code> [[http://unix.stackexchange.com/questions/265755/fedora-23-can-i-safely-delete-files-in-var-cache-packagekit-metadata-updates|Source]]

====== /var/log/journal/* ======
<code>$ journalctl --disk-usage
sudo gedit /etc/systemd/journald.conf
=> set following parameter: SystemMaxUse=50M
$ sudo systemctl restart systemd-journald.service</code> [[http://unix.stackexchange.com/questions/130786/can-i-remove-files-in-var-log-journal-and-var-cache-abrt-di-usr|Source]]