Hi,
I have made an all-in-one mail to the list as I'm not subscribed (Chris let me know in PM that there are messages sent to the list only, thanks, Chris), this keeps things simple and concise. I hope you don't mind. -------------------------------------------------------------------- (Proceeding according to Alex' message (https://lists.debian.org/debian-user/2016/02/msg00129.html) link to mail archives https://lists.debian.org/debian-user/2014/05/msg00562.html root@mymachine:~# LC_ALL=C apt-cdrom -d /media/cdrom/debian-testing-amd64-DVD-1.iso/ -mn ident Using CD-ROM mount point /media/cdrom/debian-testing-amd64-DVD-1.iso/ Identifying... [3abc47568bdd7e0b8c26d87fe7de50eb-2] Stored label: root@mymachine:~# LC_ALL=C apt-cdrom -d /media/cdrom/debian-testing-amd64-DVD-1.iso/ add Using CD-ROM mount point /media/cdrom/debian-testing-amd64-DVD-1.iso/ Unmounting CD-ROM... Waiting for disc... Please insert a Disc in the drive and press [Enter] Mounting CD-ROM... Identifying... [3abc47568bdd7e0b8c26d87fe7de50eb-2] Scanning disc for index files... Found 0 package indexes, 0 source indexes, 0 translation indexes and 0 signatures E: Unable to locate any package files, perhaps this is not a Debian Disc or the wrong architecture? E: No CD-ROM could be auto-detected or found using the default mount point. You may try the --cdrom option to set the CD-ROM mount point. See 'man apt-cdrom' for more information about the CD-ROM auto-detection and mount point. ----- Brian (https://lists.debian.org/debian-user/2016/02/msg00137.html sources list (only one entry, the following) deb [ trusted=yes ] file:/media/cdrom/debian-testing-amd64-DVD-1.iso/ stretch main DVD directory was already there and mounted mount /dev/sdb1 /media/cdrom/debian-testing-amd64-DVD-1.iso/ apt-get update Failed to fetch file:/media/cdrom/debian-testing-amd64-DVD-1.iso/dists/stretch/main/binary-amd64/Packages File not found - /media/cdrom/debian-testing-amd64-DVD-1.iso/dists/stretch/main/binary-amd64/Packages (2: File or directory not found) Some index files failed to download. They have been ignored, or old ones used instead. ----- Andyc (https://lists.debian.org/debian-user/2016/02/msg00145.html) mkdir /media/7825-FBEA less /etc/fstab /dev/disk/by-id/usb-Generic_Flash_Disk_3F27C183-0:0-part1 /media/7825-FBEA auto nosuid,nodev,nofail,noauto,x-gvfs-show 0 0 sources.list deb [ trusted=yes ] file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch main contrib apt-get update Get:1 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch InRelease Ign:1 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch InRelease Get:2 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch Release Ign:2 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch Release Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Ign:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Get:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Ign:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Get:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Ign:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Get:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Ign:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Ign:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Get:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Ign:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Get:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Ign:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Get:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Ign:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Ign:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Get:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Ign:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Get:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Ign:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Get:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Ign:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Ign:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Get:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Ign:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Get:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Ign:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Get:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Ign:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Ign:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Get:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Ign:5 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-en Get:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Ign:6 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de Get:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Ign:7 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main Translation-de_DE Get:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages Err:3 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main amd64 Packages File not found - /media/7825-FBEA/debian-testing-amd64-DVD-1.iso/dists/stretch/main/binary-amd64/Packages (20: Not a directory) Get:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages Ign:4 file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso stretch/main all Packages W: Failed to fetch file:/media/7825-FBEA/debian-testing-amd64-DVD-1.iso/dists/stretch/main/binary-amd64/Packages File not found - /media/7825-FBEA/debian-testing-amd64-DVD-1.iso/dists/stretch/main/binary-amd64/Packages (20: Not a directory) E: Some index files failed to download. They have been ignored, or old ones used instead. E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? ------------ So, what's really astonishing is the fact that I'm logged in as root and "could not get lock". So, I guess that it is apt that's lacking necessary privileges here, but it's just a guess. I'll keep on trying...,now, again the loop mount I tried earlier as Alex told me, but unfortunately it didn't work. Maybe I have made a mistake. Thanks Andyc, and thanks to all of you, curty, Brian, Chris, Alex and whoever I have omitted. Stephan