On Mon, Apr 24, 2017 at 9:53 AM, James B. Byrne <byrnejb at harte-lyne.ca> wrote: > sha256sum /dev/sr0 > Which gave this result: > sha256sum: /dev/sr0: Input/output error isoinfo -d -i /dev/sr0 | grep -i -E 'block size|volume size' dd if=/dev/cdrom bs=<block size from above> count=<volume size from above> | sha256sum Reference: https://www.thomas-krenn.com/en/wiki/Create_an_ISO_Image_from_a_source_CD_or_DVD_under_Linux