stdin: Not a typewriter stdin: Not a typewriter stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found stdin: Not a typewriter /init: line 7: can't open /dev/sr0: No medium found stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found stdin: Not a typewriter /init: line 7: can't open /dev/sr0: No medium found stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found Generating locales... en_US.UTF-8... up-to-date Generation complete. Resetting /etc/default/keyboard adduser: The user `it' already exists. Using CD-ROM mount point /cdrom/ Identifying... [d48ac21f856e4f6d588babea70678bb8-2] Scanning disc for index files... Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures This disc is called: 'It' Copying package lists...gpgv: Signature made Wed Apr 16 20:59:51 2014 UTC using DSA key ID FBB75451 gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key " Reading Package Indexes... 0% Reading Package Indexes... Done Writing new source list Source list entries for this disc are: deb cdrom:[It]/ multiboot/ubuntu-gnome-14.04-desktop-amd64/dists/trusty/multiverse/binary-amd64/ deb cdrom:[It]/ multiboot/ubuntu-gnome-14.04-desktop-amd64/dists/trusty/universe/binary-amd64/ deb cdrom:[It]/multiboot/ubuntu-gnome-14.04-desktop-amd64/ trusty main restricted Repeat this process for the rest of the CDs in your set.