Help with a dual layer backup

Will my NEC ND-3520A with standard firmware (I think 1.4 )back up my sat nav dvd which holda 6.7ghz of data and are there any special precautions I need to take Thanks

i have seen a lot of posts were people are trying to backup sat nav discs, and i don`t think people have had much succses. you could try using dvddecrypter, select iso read then if it reads it to hard drive ok then burn using iso write, using verbatim dl media.

The disc may be uncopyable.