Writing a recordable CD-ROM (either a CD-R or CD-RW) consists of two steps: first, constructing an ISO image file that is the exact filesystem image of the CD-ROM, and second, writing the image file onto the CD-ROM medium.
If we want to make an ISO image of an existing CD-ROM, we can use
dd to read all the data blocks off the CD-ROM and copy them to a local file. Say we had an Ubuntu CD and we wanted to make an ISO file that we could later use to make more copies. After inserting the CD and determining its device name (we’ll assume /dev/cdrom), we can make the ISO file like so:
dd if=/dev/cdrom of=ubuntu.iso
This technique works for data DVDs as well, but it will not work for audio CDs as they ...