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<span class="fxxl"><b>dvdisaster</b></span>
<i>Version 0.72.4 / 0.72 (pl4)</i>
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<span class="fxxl"> </span><a href="http://dvdisaster.net/en/">To the Internet version</a>
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<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos60.html">The big picture</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos10.html">Scanning media for errors</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos20.html">Putting error correction data on a separate file</a></span></td></tr>
<tr><td></td><td style="vertical-align:top; font-size:small;">-</td><td><span class="fs">Decision help</span></td></tr>
<tr><td></td><td style="vertical-align:top; font-size:small;">-</td><td><span class="fs"><a href="howtos22.html">Basic settings for reading</a></span></td></tr>
<tr><td></td><td style="vertical-align:top; font-size:small;">-</td><td><span class="fs"><a href="howtos23.html">Creating the error correction file</a></span></td></tr>
<tr><td></td><td style="vertical-align:top; font-size:small;">-</td><td><span class="fs"><a href="howtos24.html">Archiving error correction files</a></span></td></tr>
<tr><td></td><td style="vertical-align:top; font-size:small;">-</td><td><span class="fs"><a href="howtos25.html">Advanced settings</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos30.html">Putting error correction data on the medium</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos40.html">Recovering media images</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos50.html">Getting information about images and error correction data</a></span></td></tr>
<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtos90.html">Testing image compatibility</a></span></td></tr>
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<tr><td><span class="fl"><b>Creating error correction data</b></span></td>
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<tr><td><i>Decision help</i></td></tr>
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<h3 class="top">Decision help</h3>
Error correction data can be either created in form of a separate error
correction file or it can be placed directly onto the medium.
Click on the answers to the following questions to find out which
method is most appropriate for you.<p>
<i>Do you need error correction data for a medium which already exists?</i>
<ul>
<li><a href="howtos21_answer=1.html" class="active">Yes, the medium has already been written.</a></li>
<li><a href="howtos21_answer=2.html" class="passive">No, but I am planning to write the medium now.</a></li>
</ul>
You need to create an <a href="howtos22.html">error correction file</a>
because an already existing medium can not be augmented with error correction data.
<h3>More information on keeping error correction data</h3>
dvdisaster helps protecting your media from data loss by
forehanded<sup>*)</sup> creation of error correction data.
Error correction data must be treated like normal backup data, e.g.
you need to keep it available during the whole lifetime of the
respective medium.<p>
The easiest way is storing the error correction data on the medium
you want to protect. But this is only possible if the medium has not yet
been written: To employ this method you need to create an ISO image first,
then augment this image with error correction data, and finally write
the augmented image to the medium.<p>
If the medium has already been written, or insufficient space is left for
augmenting the image, you still can create error correction data in form
of a free-standing error correction file.
This file must then be stored somewhere else, e.g. you need to take additional
provisions to <a href="howtos24.html">archive</a> your error
correction files.<p>
More information about the pro and con of these methods
can be found in the <a href="qa33.html#table">background information</a> section.
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<a name="footnote"><sup>*)</sup>Let's repeat again for clarity: Error correction data must be created before the medium becomes defective. It is not possible to create error correction data from defective media; in that case unreadable sectors can not be recovered.</a>
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<i> Copyright 2004-2012 Carsten Gnörlich.<br>
Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.
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