My Fedora (linux) box upgraded to 27

Today after some days of the new release of Fedora (the 27), I used the CLI to upgrade my PC. But I made a little mistake. I forget to check free disk space.
So while

"sudo dnf system-upgrade download --releasever=27"

went downloading, at some time the system notified free disk space at minumum (~1,1G). So during the process I deleted some files obtaining about 8 G free.    
Neverthless, at the end of the command many recent files was signed not installable because of insufficient space.
Tried

"sudo dnf system-upgrade reboot" 

and system rebooted twice but without upgrade. Re-launching previous dnf s*-u* download command resulted in skipping pkgs as already downloaded (but incomplete).

So after manual remove of /var/cache/PackageKit/27 and repeating the process, this time all went fine.

Check free disk space, please! (Perhaps in GUI this doesn't happen!?)

Thank you all!