Stop OH / Start OH
Depends on the installation:
for example:
http://docs.openhab.org/installation/linux.html#service
start, restart, stop and retrieve status
sudo systemctl start openhab2.service
sudo systemctl restart openhab2.service
sudo systemctl stop openhab2.service
sudo systemctl status openhab2.service
for example
FTP Client: Log in with FTP Client, delete all subfolders and files from folders above
Samba Mount: Mount Fodlers via Samba (if enabled), delete all subfolders and files from folders above