stdin: Not a typewriter
/init: line 7: can't open /dev/sdc: No medium found
/init: line 7: can't open /dev/sdc: No medium found
Generating locales...
  en_US.UTF-8... done
Generation complete.
pwconv: failed to change the mode of /etc/passwd- to 0600
Using CD-ROM mount point /cdrom/
Identifying... [2dcfc167deacd04472f2ab9861886da9-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'It'
This disc is called: 
'It'
Copying package lists...gpgv: Signature made Fri Apr 17 21:42:33 2015 UTC using DSA key ID FBB75451
gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>"

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-desktop-amd64/dists/vivid/multiverse/binary-amd64/
deb cdrom:[It]/ multiboot/ubuntu-gnome-desktop-amd64/dists/vivid/universe/binary-amd64/
deb cdrom:[It]/multiboot/ubuntu-gnome-desktop-amd64/ vivid main restricted
Repeat this process for the rest of the CDs in your set.