I cannot mount a data DVD using Ubuntu 12.04. I can read the DVD using a different OS, so the DVD is not the problem. I can read other CDs using Ubuntu. The error I get is: $ sudo mount /dev/dvd /cdrom mount: no medium found on /dev/sr0 The relevant output from lshw is: *-cdrom description: DVD reader product: DVD/CDRW UJDA775 vendor: MATSHITA physical id: 0.0.0 bus info: scsi@4:0.0.0 logical name: /dev/cdrom logical name: /dev/cdrw logical name: /dev/dvd logical name: /dev/sr0 version: CB03 capabilities: removable audio cd-r cd-rw dvd configuration: ansiversion=5 status=nodisc I have installed ubuntu-restricted-extras and run /usr/share/doc/libdvdread4/install-css.sh.