Generating locales...
  en_US.UTF-8... done
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_xubuntu-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... [fce63ccecfa6ade1b557830b50f92067-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Xubuntu 15.04 _Vivid Vervet_ - Alpha i386 (20150218)'
This disc is called: 
'Xubuntu 15.04 _Vivid Vervet_ - Alpha i386 (20150218)'
Copying package lists...gpgv: Signature made Wed Feb 18 10:53:46 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:[Xubuntu 15.04 _Vivid Vervet_ - Alpha i386 (20150218)]/ vivid main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.