Backing up dvd-9

Trying to backup a dvd-9 do i understand this correctly and that means the -9 is a dual layer disc. been doing great so far with everything else this movie of mine has 4 hours of video and would like to know the best way to back this up i have about every piece of software there is. Opinion should i go with dvd rebuilder to get it back to the best quality…would like some suggestions please this is my first dvd-9 that i am aware of or at least the 1st one i am trying that is 4 hours long…thanks all

Yes 9 is a dual layer disk. If you are trying to burn a dl 9 to another dl 9 then you wont need a compression program it should copy one to one. I usually use clone cd for this. If you are trying to compress a dl 9 to a sl 5 then Rebuilder is probably the best way to go. Or you could use clone dvd 2 and split it over two dvds.