Generating locales (this might take a while)...
  hu_HU.UTF-8... done
Generation complete.
pwconv: failed to change the mode of /etc/passwd- to 0600
Using CD-ROM mount point /cdrom/
Identifying... [8fb5fe7e69b40ebbdac4ea35059659fe-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu-Studio 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)'
This disc is called: 
'Ubuntu-Studio 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)'
Copying package lists...gpgv: Signature made Wed Feb 28 19:02:06 2018 UTC using RSA key ID EFE21092
gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key (2012) <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 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)]/ xenial main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.
W: No valid records were found.