~$ sudo apt update
Ign:1 cdrom://Ubuntu-GNOME 17.10 _Artful Aardvark_ - Alpha amd64 (20170523) artful InRelease
Err:2 cdrom://Ubuntu-GNOME 17.10 _Artful Aardvark_ - Alpha amd64 (20170523) artful Release
  Usare apt-cdrom per far riconoscere questo CD-ROM da APT. apt-get update non può essere usato per aggiungere nuovi CD-ROM
Trovato:3 http://archive.canonical.com/ubuntu artful InRelease
Scaricamento di:4 http://it.archive.ubuntu.com/ubuntu artful InRelease [237 kB]
Trovato:5 http://security.ubuntu.com/ubuntu artful-security InRelease                
Trovato:6 http://it.archive.ubuntu.com/ubuntu artful-updates InRelease               
Trovato:7 http://it.archive.ubuntu.com/ubuntu artful-backports InRelease
Scaricamento di:8 http://it.archive.ubuntu.com/ubuntu artful/main i386 Packages [1.174 kB]
Scaricamento di:9 http://it.archive.ubuntu.com/ubuntu artful/main amd64 Packages [1.177 kB]
Scaricamento di:10 http://it.archive.ubuntu.com/ubuntu artful/universe amd64 Packages [8.281 kB]
Scaricamento di:11 http://it.archive.ubuntu.com/ubuntu artful/universe i386 Packages [8.244 kB]
Lettura elenco dei pacchetti... Fatto                                                
E: The repository 'cdrom://Ubuntu-GNOME 17.10 _Artful Aardvark_ - Alpha amd64 (20170523) artful Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.