02 September 2022

Saving data off a scratched DVD

I had a DVD with files on it that I needed. Unfortunately, it was giving me errors when trying to pull them off. Here is what I did to try to recover as much data as possible.

  • Install ddrescue and a gui for visualizing its progress
    • sudo apt-get install gddrescue ddrescueview
  • Run a first pass with no retries to get as much info as possible
    • ddrescue -dn -b2048 /dev/sr0 disk.img disk.mapfile
  • Retry failed blocks
    • ddrescue -d -r5 -b2048 /dev/sr0 disk.img disk.mapfile
  • Description of the options:
    • /dev/sr0: the dvd drive
    • disk.img: the file to create
    • disk.mapfile: the mapfile that keeps track of the status of the recovery
    • -d: Use direct disc access for input (aka, no caching)
    • -n: Skip the scraping phase
    • -b2048: block size of 2048, use for cdroms and dvd
      • defaults to 512
    • -r5: retry 5 passes
      • -1 for infinite passes