Fix the apt-get install error: “Media change: please insert the disc labeled ...”
In order to avoid Debian to search for packages on a non-existent CDROM, which is most likely not present on a VPS, you should change a simple parameter on the /etc/apt/sources.list file. You need to modify the aforementioned file if you get an output like this while using apt-get to install default packages:
Media change: please insert the disc labeled
'Debian GNU/Linux 7.0.0 _Wheezy_ - Official amd64 CD Binary-1 20130504-14:44'
in the drive '/media/cdrom/' and press enter
This file contains all your package sources. You might find a deb cdrom:[Debian GNU/Linux 7.0.0 _Wheezy_ - Official amd64 CD Binary-1 20130504-14:44]/ wheezy main line indicating a local CDROM as a package source. Comment it out by placing a # symbol at the beginning of the line and save the file.