stdin: Not a typewriter stdin: Not a typewriter stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 3: can't open /dev/sr0: No medium found stdin: Not a typewriter /init: line 3: can't open /dev/sr0: No medium found stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 3: can't open /dev/sr0: No medium found stdin: Not a typewriter /init: line 3: can't open /dev/sr0: No medium found stdin: Not a typewriter umount: can't umount /cdrom: Device or resource busy /init: line 3: can't open /dev/sr0: No medium found Generating locales... en_US.UTF-8... up-to-date Generation complete. adduser: The user `it' already exists. ln: /root/usr/sbin/anacron: File exists ln: /root/lib/systemd/system/cdrom.mount: File exists Using CD-ROM mount point /cdrom/ Identifying... [09131eaff8ebc3a0c841d4fc112f227c-2] Scanning disc for index files... Found 4 package indexes, 0 source indexes, 0 translation indexes and 2 signatures This disc is called: 'It' Copying package lists...gpgv: Signature made Wed Oct 21 17:18:41 2015 BST using DSA key ID FBB75451 gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key " gpgv: Signature made Wed Oct 29 23:24:11 2008 GMT using DSA key ID FBB75451 gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key " Reading Package Indexes... 0% Reading Package Indexes... 4% Reading Package Indexes... Done Writing new source list Source list entries for this disc are: deb cdrom:[It]/multiboot/ubuntu-15.10-desktop-i386/ wily main restricted deb cdrom:[It]/multiboot/ubuntu-8.10-desktop-i386/ intrepid main restricted Repeat this process for the rest of the CDs in your set.