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... [3c8ca10112e8866fd769bcd54ae2eb2a-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Xubuntu 16.10 _Yakkety Yak_ - Alpha amd64 (20160531)'
This disc is called: 
'Xubuntu 16.10 _Yakkety Yak_ - Alpha amd64 (20160531)'
Copying package lists...gpgv: Signature made Tue May 31 02:27:05 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:[Xubuntu 16.10 _Yakkety Yak_ - Alpha amd64 (20160531)]/ yakkety main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.