How to  copy a dvd 
you mount the dvd  to /mnt/dvd   
then you have to produce  the VOB files 
do
 
--------------------->vobcopy -i /mnt/dvd -m  

and it produces a dir   with the vob files(CAPITAL-LETTERS or mkisofs -dvd-video wont work) in it 
now you have to  make an iso image out of the vob files 
BUT if the DVD exceeds  4.7GB you have to compress it 
so you can use K9copy GUI to do it 
i would like a cmd way to do it 

so you do 
 
------------------> mkisofs -dvd-video -o dvd.iso /path/of/your/vob/files

SOS 
 -dvd-video
              Generate  DVD-Video  compliant  UDF file system. This is done by
              sorting the order of the content of the appropriate files and by
              adding padding between the files if needed.  Note that the sort-
              ing only works if the DVD-Video  filenames  include  upper  case
              characters only.

IF the vob files are in lower case  the -dvd-video option  will be ommited or mkisofs will complain 
then you can burn it on to your dvd 


----------------> growisofs -dvd-compat -Z /dev/hdc=dvd.iso 



you can also do it  directly  but it still uses a pipe 
as
-----------------> growisofs  -dvd-video -udf -Z /dev/hdc dvd/

--------->  mkisofs -dvd-video -udf dvd/ | builtin_dd of=/dev/hdc obs=32k seek=0'

OR if the vob files are still in lower case this  worked  

------------------------> growisofs  -dvd-compat -udf -Z /dev/hdc  dvd/

/dev/hdc=your dvd player 

dvd/= path to your vob files