147 lines
5.2 KiB
HTML
147 lines
5.2 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<meta http-equiv="content-type" content="text/html; charset=UTF-8">
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<title>dvdisaster complements quality scans</title>
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<link rel="stylesheet" type="text/css" href="../include/dvdisaster.css">
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</head>
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<body>
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<!-- Title header -->
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<table width="100%" cellpadding="0" border="0">
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<tr>
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<td align="left">
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<span class="fxxl"><b>dvdisaster</b></span>
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<i>Version 0.72.4 / 0.72 (pl4)</i>
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</td>
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<td align="right">
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<span class="fxxl"> </span><a href="http://dvdisaster.net/en/">To the Internet version</a>
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<a href="../cs/index20.html"></a>
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<a href="../de/index20.html"></a>
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<a href="../ru/index20.html"></a>
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</td>
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</tr>
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</table>
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<table width="100%" cellpadding="0" border="0">
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<tr>
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<td colspan="2" class="hsep"></td>
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</tr>
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<tr><td colspan="2" style="height: 10px">
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</td></tr>
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</table>
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<table width="100%" cellspacing=0>
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<tr>
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<td style="background-color:#f0f0f0; vertical-align:top; width:20%;">
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<table width="100%" cellpadding="10">
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<tr>
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<td>
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<span class="fs"><b>Contents</b></span>
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<table width="100%" cellpadding="0" cellspacing="0">
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<tr>
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<td class="hsep"></td>
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</tr>
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</table><p>
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<table width="100%">
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<tr><td colspan=3><span class="fs"><a href="news.html">News</a></span></td></tr>
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<tr><td></td><td></td><td style="height:10px;"></td></tr>
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<tr><td colspan=3><span class="fs"><a href="index.html">Overview</a></span></td></tr>
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<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="index10.html">Examples of the error correction</a></span></td></tr>
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<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs">dvdisaster complements quality scans</span></td></tr>
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<tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="index30.html">Pro and con of dvdisaster</a></span></td></tr>
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<tr><td></td><td></td><td style="height:10px;"></td></tr>
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<tr><td colspan=3><span class="fs"><a href="howtos.html">Howtos</a></span></td></tr>
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<tr><td></td><td></td><td style="height:10px;"></td></tr>
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<tr><td colspan=3><span class="fs"><a href="download.html">Download</a></span></td></tr>
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<tr><td></td><td></td><td style="height:10px;"></td></tr>
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<tr><td colspan=3><span class="fs"><a href="qa.html">Questions and Answers</a></span></td></tr>
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<tr><td></td><td></td><td style="height:10px;"></td></tr>
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<tr><td colspan=3><span class="fs"><a href="feedback.html">Bug reporting</a></span></td></tr>
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</table>
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</td>
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</tr>
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</table>
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</td>
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<td></td>
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<td style="vertical-align:top; width:77%;" rowspan="2">
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<h3 class="top">dvdisaster as a complement to quality scans</h3>
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<a href="qa.html#pipo">Quality scans</a>, e.g. C2 error or PI/PO scans are a valuable
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tool for testing the results of the media writing process.<p>
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But quality scans are <b>not</b> a reliable means of <b>predicting
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the lifetime</b> of optical media. <br>
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Consider we are looking for the right time
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to copy a worn-out medium onto a new one:
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<ul>
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<li>Too early: Copying media because of a bad quality scan is cost-ineffective.
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Sometimes such media remain readable much longer than expected.<p></li>
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<li>Too late: When the quality scan reveals unreadable sectors some
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data has already been lost.<p></li>
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<li>Right before the medium fails: The ideal case, but how to tell?
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</ul>
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However, we could do it the dvdisaster way:
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<ul>
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<li><a href="howtos20.html">Create error correction data</a> for the medium.<p></li>
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<li><a href="howtos10.html">Scan the medium</a> regularly. Use it until the first read errors occur.<p></li>
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<li><a href="howtos40.html">Recover</a> the read errors <a href="howtos40.html">using the error correction data</a>.
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Write the recovered image to a new medium.</li>
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</ul>
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<p>
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<a href="index30.html">Pro and con of dvdisaster at a glance...</a>
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</td> <!-- end of page contents -->
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</tr>
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<tr valign="bottom">
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<td style="background-color:#f0f0f0;">
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<table cellpadding="10"><tr><td><a href="http://dvdisaster.net/legacy/en/index.html"><span class="fs"></span></a></td></tr></table>
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<td></td>
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<td></td>
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</table> <!-- end of main body table -->
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<tr><td colspan="2" class="hsep"></td>
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</tr>
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<tr>
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<td align="center">
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<span class="fs">
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<i> Copyright 2004-2012 Carsten Gnörlich.<br>
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Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.
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</i>
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</span>
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</td>
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</tr>
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<tr><td colspan="2" class="hsep"></td>
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</tr>
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</table>
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</body>
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</html>
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