Copy DVD to ISO with dd and isoinfo

Run this command to determine the volume size:

isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size'

The output might be similar to this:
Logical block size is: 2048
Volume size is: 2206055


Then run dd using information as of above:

dd if=/dev/cdrom of=dvd.iso bs=2048 count=2206055