Assuming both ends are send and receive, if I formated my device (a) and regenerate the folder manually and start the syncthing is it going to get the files from the other end (b) or it will deleted the files of the other end?
It will complain that the folder marker (
.stfolder directory) is missing. If you recreate that, it will wipe everything on the other end. The proper way if you reset the filesystem is to also “reset” the folder, i.e. remove and add it again.
Ok i get it, but you say “reset the folder” you mean inside the syncthing in the a device ?
Sure this is all about the device where you format.