If your linux does not play DVD correctly, try this:
sudo apt-get install libdvdread4
Backup DVD as ISO file:
ddrescue -d /dev/dvd ~/dvd_backup.iso ~/dvd_backup.log
This is just an example. Please replace the arguments with those of your specific backup task.
According to the following post: http://www.cmdln.org/2010/01/22/backing-up-disney-dvds/
ddrescue –n –b 2048 /dev/dvd output.iso
dvdbackup –M –i output.iso –o dvd_structure
mkisofs –dvd-video –o clean_dvd.iso dvd_structure
Step 1 copys the DVD to disk block by block but any bad sectors found zero data is filled in. At this point you are left with a DVD iso that has the copy protection removed but the encryption is still intact. Step 2 extract the contents to a directory. This second step leaves you with the structure of a dvd without the encryption. I want to preserve everything about the original DVD (except the copy protection and encryption) so I used the mirror option. This leaves me with all the features and original menus. Step 3 take the DVD structure and pack it up into a nice ISO.