Provided by: dvdisaster_0.72.4-1_amd64 bug


       DVDISASTER - data loss/scratch/aging protection for CD/DVD media


       dvdisaster  [-r|-c|-f|-s|-t[q]|-u]  [-d  device]  [-p  prefix] [-i image] [-e eccfile] [-o
       file|image] [-a codec-list] [-j n] [-n n%] [-m n] [-v] [-x n]  [--adaptive-read]  [--auto-
       suffix]  [--cache-size  n]  [--dao]  [--defective-dump  d] [--driver d] [--eject] [--fill-
       unreadable n] [--ignore-fatal-sense] [--ignore-iso-size] [--internal-rereads n] [--old-ds-
       marker]  [--prefetch-sectors  n]  [--raw-mode  n]  [--read-attempts n-m] [--read-medium n]
       [--read-raw] [--speed-warning n] [--spinup-delay n]


       DVDISASTER provides a margin of safety against data loss on CD and  DVD  media  caused  by
       scratches  or  aging  media.  It  creates  error  correction data which is used to recover
       unreadable sectors if the disc becomes damaged at a later time.


       dvdisaster -d /dev/hdc -s
              Scans the medium in drive /dev/hdc for errors.

       dvdisaster -d /dev/hdc -i medium.iso -r
              Reads an image from drive /dev/hdc into the file medium.iso.

       dvdisaster -d /dev/hdc -i medium.iso --read-raw -r
              Creates an image as described above. Each sector's integrity is verified  by  using
              its  EDC  and  L-EC  raw data. Only possible for CD media; otherwise the --read-raw
              option is silently ignored.

       dvdisaster -d /dev/hdc -i medium.iso --read-attempts n-m -r
              Creates an image as described above. Defective sectors are retried at least n times
              and  at most m times. Recovery of defective CD media may improve when combined with

       dvdisaster -d /dev/hdc -i medium.iso -e corr.ecc -r --adaptive-read
              Uses the adaptive reading strategy to read an image from drive  /dev/hdc  into  the
              file  medium.iso.   Reading  will stop when enough data has been gathered to repair
              the image using the error correction file corr.ecc.

       dvdisaster -i medium.iso -e corr.ecc -c
              Creates an error correction file corr.ecc for the image medium.iso.

       dvdisaster -i medium.iso -mRS02 -n 350000 -c
              Augments the image medium.iso with  error  correction  information,  expanding  the
              image  to  no more than 350000 sectors. If -n is omitted the image will be expanded
              to the smallest possible medium size (CD,  DVD,  DVD9).   Note  the  missing  blank
              between -m and RS02.

       dvdisaster -i medium.iso -e corr.ecc -f
              Repairs the image file medium.iso using the error correction file corr.ecc.

       dvdisaster -i medium.iso -e corr.ecc -t
              Verifies  the  image  medium.iso  with  information  from the error correction file

       NOTE:  Omit the -e corr.ecc options when working with augmented  images  in  the  examples


       Action selection (at least one action must be specified):

       -r, --read
              Read  the medium image to hard disc. Use -rn-m to read a certain sector range, e.g.

       -c, --create
              Create .ecc information for the medium image.

       -f, --fix
              Try to fix medium image using .ecc information.

       -s, --scan
              Scan the medium for read errors.

       -t, --test, -tq, --test=q
              Test integrity of the .iso and .ecc files. When  the  "q"  option  is  given,  only
              information is output which can be gathered without fully scanning the files.

       -u, --unlink
              Delete .iso files (when other actions complete).

       Drive and file specification:

       -d, --device device
              read from given device (default: /dev/cdrom).

       -p, --prefix prefix
              prefix of .iso/.ecc file (default: medium.* ).

       -i, --image imagefile
              name of image file (default: medium.iso).

       -e, --ecc eccfile
              name of parity file (default: medium.ecc).

       -o, --ecc-target file|image
              Specifies  whether  RS03  should  create error correction files or augmented images
              (default: image).

       Tweaking options (see manual before using!):

       -a, --assume codec1,codec2,...
              Assumes that the image is augmented with one of the given codecs.  This enables  an
              exhaustive  search  for  codec  signatures and might be helpful for detecting error
              correction information on  damaged  media.  If  the  image  does  not  contain  the
              specified  error  correction  information, a significant amount of CPU and I/O time
              may be wasted.
              Possible values are RS02 and RS03.

       -j, --jump n
              jump n sectors forward after a read error (default: 16).

       -n, --redundancy n[unit]
              Error correction data redundancy. Allowed values depend on the codec:

              RS01- and RS03-error correction files
                     -n x  creates error correction file with x roots.
                     -n x% creates error correction file with x percent redundancy.
                     -n xm creates error correction file of approx. x MB size.
                     -n normal - optimized codec for 14.3% redundancy/32 roots.
                     -n high   - optimized codec for 33.5% redundancy/64 roots.

              RS02 images:
                     -n CD   augments image suitable for CD media.
                     -n DVD  augments image suitable for DVD media.
                     -n DVD9 augments image suitable for DVD9 media.
                     -n BD   augments image suitable for BD media.
                     -n BD2  augments image suitable for two layered BD media.
                     -n x    augments image using approx. x sectors in total.
                     -n x%   augments image with approx. x% redundancy.
                     -n xr   augments image with x roots error correction data.

       -m, --method n
              lists/selects error correction methods (default: RS01).
              Possible values are RS01 and RS02.

       -v, --verbose n%
              more diagnostic messages

       -x, --threads n
              Use n threads for the RS03 codec. Use 2 or 4 threads for 2  or  4  core  processors
              respectively.   On  larger  machines  save  one  core  for housekeeping; e.g. use 7
              threads on an eight core machine.

              use optimized strategy for reading damaged media.

              automatically add .iso and .ecc file suffixes.

       --cache-size n
              image cache size in MB during -c mode (default: 32MB).

       --dao  assume DAO disc; do not trim image end.

       --defective-dump d
              Specifies the sub directory for storing incomplete raw sectors.

       --driver d (Linux only)
              Selects between the sg  (SG_IO)  driver  (default  setting)  and  the  older  cdrom
              (CDROM_SEND_PACKET)  driver  for accessing the optical drives.  Both drivers should
              work equally well; however the cdrom driver is known to cause  system  failures  on
              some  ancient  SCSI  controllers.   The older cdrom driver was the default upto and
              including dvdisaster 0.72.x; if the now pre-selected sg driver changes something to
              the worse for you please switch back to the older driver using --driver=cdrom.

              eject medium after successful read.

       --fill-unreadable n
              fill unreadable sectors with byte n

              continue reading after potentially fatal error condition.

              By  default  getting  the  image size from the ISO/UDF filesystem is preferred over
              querying the drive as most drives report unreliable values.
              However in some rare cases the image size recorded in  the  ISO/UDF  filesystem  is
              wrong.  Some  Linux live CDs may have this problem.  If you read back the ISO image
              from such CDs and its md5sum does not match the advertised one, try re-reading  the
              image with this option turned on.
              Do  not  blindly  turn  this option on as it will most likely create sub optimal or
              corrupted ISO images, especially if you plan to use the image for error  correction
              data generation.

       --internal-rereads n
              internal read attempts for defective CD media sectors (default: -1)
              The  drive firmware usually retries unreadable sectors a few times before giving up
              and returning a read error. It is more efficient to set this to 0 or 1  and  manage
              read  attempts  through  the  --read-attempts  parameter.  Most  drives ignore this
              setting anyways. Use -1 to leave the drive at its default setting.

              Marks missing sectors in a manner which  is  compatible  with  dvdisaster  0.70  or
              The  default  marking method is recommended for dvdisaster 0.72 and later versions.
              However images marked with the current method  can  not  be  processed  with  older
              dvdisaster versions as missing sectors would not be recognized in the image.

              Do not process the same image with different settings for this option.

       --prefetch-sectors n
              number of sectors to preload during RS03 de-/encoding (default: 32)
              Using a value of n uses approx. n MB of RAM.

       --raw-mode n
              selects raw reading mode for CD media (default: 20)
              The  recommended  mode  is  20,  which  makes  the  drive  apply its built-in error
              correction to the best possible extent  before  transferring  a  defective  sector.
              However  some  drives  can  only read defective sectors using mode 21, skipping the
              last stage of the internal error correction and returning  the  uncorrected  sector

       --read-attempts n-m
              attempts n upto m reads of a defective sector.

       --read-medium n
              read the whole medium up to n times.

              performs read in raw mode if possible.

       --speed-warning n
              print warning if speed changes by more than n percent.

       --spinup-delay n
              wait n seconds for drive to spin up.


       Documentation    DVDISASTER    is   documented   by   its   own   manual,   installed   in


       DVDISASTER was written by Carsten Gnoerlich <>.

       This manual page was written by Daniel Baumann <>,  for
       the  Debian  project  (but  may be used by others). Since version 0.70 it is maintained by
       Carsten Gnoerlich.