|DVDISASTER(1)||protection for optical media||DVDISASTER(1)|
DVDISASTER - data loss/scratch/aging protection for optical media
dvdisaster [-r|-c|-f|-s|-t[q]|-u] [-d device] [-p prefix] [-i image] [-e eccfile] [-o file|image] [-a method-list] [-j n] [-n n%] [-m n] [-v] [-x n] [--adaptive-read] [--auto-suffix] [--cache-size n] [--dao] [--defective-dump d] [--driver d] [--eject] [--encoding-algorithm n] [--encoding-io-strategy n] [--fill-unreadable n] [--ignore-fatal-sense] [--ignore-iso-size] [--internal-rereads n] [--medium-info] [--old-ds-marker] [--prefetch-sectors n] [--raw-mode n] [--read-attempts n-m] [--read-medium n] [--read-raw] [--resource-file n] [--speed-warning n] [--spinup-delay n]
DVDISASTER provides a margin of safety against data loss on optical 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 --read-raw.
- 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 corr.ecc.
- Omit the -e corr.ecc options when working with augmented images in the examples above.
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. -r100-200.
- -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 method1,method2,...
- Assumes that the image is augmented with one of the given methods. This enables an exhaustive search for method 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.
- -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 method:
- -m, --method n
- lists/selects error correction methods (default: RS01).
- -v, --verbose n%
- more diagnostic messages
- -x, --threads n
- Use n threads for encoding with the RS03 method. 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 MiB during -c mode (default: 32MiB).
- 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 up to 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.
- --encoding-algorithm [32bit|64bit|SSE2|AltiVec]
- This option affects the speed of generating RS03 error correction data. dvdisaster can either use a generic encoding algorithm using 32bit or 64bit wide operations running on the integer unit of the processor, or use processor specific extensions.
- --encoding-io-strategy [readwrite|mmap]
- This option controls how dvdisaster performs its disk I/O while creating error correction data with RS03. Try both options and see which performs best on your hardware setting.
- --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.
- --internal-rereads n
- internal read attempts for defective CD media sectors (default: -1)
- Prints information about the currently inserted medium.
- Marks missing sectors in a manner which is compatible with dvdisaster 0.70 or older.
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)
- --raw-mode n
- selects raw reading mode for CD media (default: 20)
- --read-attempts n-m
- attempts n up to m reads of a defective sector.
- --read-medium n
- read the whole medium up to n times.
- performs read in raw mode if possible.
- --resource-file n
- Specifies the path to the configuration file (default: $HOME/.dvdisaster)
- --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 /usr/share/doc/dvdisaster
DVDISASTER was written by Carsten Gnoerlich <firstname.lastname@example.org>.
This manual page was written by Daniel Baumann <email@example.com>, for the Debian project (but may be used by others). Since version 0.70 it is maintained by Carsten Gnoerlich.