Wilfrid, can you post a screen shot of your Settings-Library screen?
I am am pretty sure that analysis is still underway.
The QNAP will provide a nice Roon Core when finished, but it will struggle with upsampling to more than one zone or other DSP’ing.
Have some patience and try it out, if it performs to your needs, no need to have a dirty old computer running separately! 
I wanted to see the library, think its called “Bibliotheque musique” or something in your translation?
If you select that, you will see the status of analysis displayed on the same place as where you select the number of Cores to use for Analysis.
Very well, as you can see it is analyzing. 633 tracks out of 180436 (since the library was last saved. It’ll take quite some time, but will bee usable during the time.
You could very likely reduce noice and heat by selecting the slowest analysis speed in the pop down menu. (or shut it down completely to get a feel for the servers performance as it will appear when finished)
Thanks Mikael for your help 
Do you know how i can install the Core on a pc different from where the remote is installed ?
You can download and install “Roon Server” (or just “Roon”, for the complete package) for most use cases from the download page
There are a few different scenarios, so you can just follow the install instructions and descriptions for what suits you best.
Have a good and thorough read and you will do fine! 
You should be able to back-up your existing setup - turn off the analysis first. then restore the back-up to the new core location. Shut down your QNAP core once the backup is done. If you back up to the NAS then that’s easier to restore from as a network location.
Again thanks Guy
