dvdisaster Version 0.62
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Contents

Overview
Examples and screen shots
·Invoking the graphical user interface
·Creating a medium image
·Generating error correction files
·Scanning a medium for errors
·Recovering a medium image
·Compare image against error correction data
·Configuration
Download
Command line mode
Questions and Answers
Imprint

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. Try to read in as much data as possible into an image file.

Select the drive and image file name, then read in the medium image by clicking the "Read" button as described in "Creating the medium image". Please note that reading a damaged medium may take several hours to complete.

2. Perform the image reconstruction.

Select the error correction file name and click the "Fix" button. It is normal to experience phases of high hard drive activity during image reconstruction.


Screen shot: Repairing the image
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).

Copyright 2004,2005 Carsten Gnörlich.
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