Yes, I did it and it created a lot of empty directories. Then, I thought it was an error and I changed back the settings to database, then I disabled the plugin, changed the pointed directory (to restart from a clean one) and re-enabled it before to set the settings to use it again. On first ticket with attachment I then taken a look at the folder and it was with empty folders as per the screenshot I attached above. Well, but I can't compromise this support desk wich is a production one about a commercial software at launch stage... So, I switched back to database and I'll do my test beside with another install when I'll have more time...Thanks for your hint