Create an ISO image of a CD or DVD in GNU/Linux

Very simple, without using auxiliary programs and from our console.

The first thing we do is make sure the CD/DVD is not mounted automatically in our system. This means that if unit appears as we manually remove it, either by using the umount command in fstab or disabling the CD/DVD is mounted automatically when you insert a disc. For convenience, I raised the first option:$ sudo umount /media/