Generating locales...
  en_US.UTF-8... up-to-date
Generation complete.
No such key 'show-notify-osd-on-scroll' in schema 'com.canonical.indicator.sound' as specified in override file '/usr/share/glib-2.0/schemas/20_ubuntustudio-default-settings.gschema.override'; ignoring override for this key.
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... [456266bdbcdcaf7142ae6d224159faca-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu-Studio 15.04 _Vivid Vervet_ - Release amd64 (20150422)'
This disc is called: 
'Ubuntu-Studio 15.04 _Vivid Vervet_ - Release amd64 (20150422)'
Copying package lists...gpgv: Signature made Wed Apr 22 12:46:09 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:[Ubuntu-Studio 15.04 _Vivid Vervet_ - Release amd64 (20150422)]/ vivid main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.
W: No valid records were found.
Processing triggers for libc-bin (2.21-0ubuntu4) ...