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 (this might take a while)...
Generation complete.
No such key 'auto-launch' in schema 'com.ubuntu.update-notifier' as specified in override file '/usr/share/glib-2.0/schemas/20_ubuntustudio-default-settings.gschema.override'; ignoring override for this key.
pwconv: failed to change the mode of /etc/passwd- to 0600
Using CD-ROM mount point /cdrom/
Identifying... [977283176d2f3fd1a941988724dae1ef-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu-Studio 16.04 LTS _Xenial Xerus_ - Beta amd64 (20160323)'
This disc is called: 
'Ubuntu-Studio 16.04 LTS _Xenial Xerus_ - Beta amd64 (20160323)'
Copying package lists...gpgv: Signature made Wed Mar 23 08:58:38 2016 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:[Ubuntu-Studio 16.04 LTS _Xenial Xerus_ - Beta amd64 (20160323)]/ xenial main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.
W: No valid records were found.