umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found /init: line 7: can't open /dev/sr0: No medium found umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found /init: line 7: can't open /dev/sr0: No medium found umount: can't umount /cdrom: Device or resource busy /init: line 7: can't open /dev/sr0: No medium found Generating locales (this might take a while)... Generation complete. pwconv: failed to change the mode of /etc/passwd- to 0600 Using CD-ROM mount point /cdrom/ Identifying... [401702d99b34d613e2af1f0d2950737b-2] Scanning disc for index files... Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures Found label 'Ubuntu-Studio 17.04 _Zesty Zapus_ - Alpha amd64 (20170219)' This disc is called: 'Ubuntu-Studio 17.04 _Zesty Zapus_ - Alpha amd64 (20170219)' Copying package lists...gpgv: Signature made Sun Feb 19 19:06:18 2017 UTC gpgv: using RSA key gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key (2012) " Reading Package Indexes... 0% Reading Package Indexes... Done Writing new source list Source list entries for this disc are: deb cdrom:[Ubuntu-Studio 17.04 _Zesty Zapus_ - Alpha amd64 (20170219)]/ zesty main multiverse restricted universe Repeat this process for the rest of the CDs in your set. W: No valid records were found.