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Recovering a medium image
To recover data from damaged media you need
the appropriate error correction file
which you have hopefully generated at a time when the medium was still fully readable.
Perform the following actions:
1. Switch the reading strategy.
Go to the Read & Scan preferences dialog
and select the adaptive reading strategy.
2. Try to read in as much data as possible into an image file.
Select the drive, image file and error correction file (2a).
dvdisaster uses the error correction file at this stage to determine
when enough data for reconstructing the image has been collected.
Start the reading process by clicking at the "Read" button (2b).
Please note that reading a damaged medium may take several hours to complete.
Screen shot: Reading the image
3. Perform the image reconstruction.
Click on the "Fix" button.
It is normal to experience phases of high hard drive
activity during image reconstruction.
Screen shot: Repairing the image
The repairing progress will be shown in percent.
Additional hints:
- The message "Good! All sectors are repaired." confirms that the medium image
has been fully recovered. The image can be written to a new
medium using a suitable CD/DVD recording software. If you need to specify the
image format, select ". i s o".
- If uncorrectable sectors remain after this stage, try reading the image again.
dvdisaster will try to re-read only the missing sectors, and this might
retrieve enough missing sectors for another successful error correction run.
Re-reading the medium on another drive might also be worthwhile as well as
performing the second read attempt at the next morning:
Some drives read better while being cold.
- The red error graph does not correlate with the spatial arrangement of
read errors on the disc: The error correction method is explicitly built to achieve
an equal distribution of medium read errors over all error correction blocks.
The green line marks the maximum capacity of the error correction. If this line is exceeded,
the image can not be recovered with the currently available data (in case of tight misses,
another reading attempt might help - see above).
- When the image has been read in by the adaptive reading strategy,
the error correction load will always be maxed out.
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