F27 -> Fedora 28 Upgrade

sudo dnf upgrade --refresh

sudo dnf install dnf-plugin-system-upgrade

sudo dnf system-upgrade download --releasever=28

sudo dnf system-upgrade reboot

Notes:
I had only a samll problem in the new system: gnome-terminal didn't load.
On bugzilla.redhat searching for gnome-terminal I found a solution that solved the "locale" issue, installing "langpacks-it".

Great!