<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Decision help</title> <link rel="stylesheet" type="text/css" href="../include/dvdisaster.css"> </head> <body> <!-- Title header --> <table width="100%" cellpadding="0" border="0"> <tr> <td align="left"> <span class="fxxl"><b>dvdisaster</b></span> <i>Version 0.72.4 / 0.72 (pl4)</i> </td> <td align="right"> <span class="fxxl"> </span><a href="http://dvdisaster.net/en/">To the Internet version</a> <a href="../cs/howtos21.html"></a> <a href="../de/howtos21.html"></a> <a href="../ru/howtos21.html"></a> </td> </tr> </table> <!-- Language chooser or separator --> <table width="100%" cellpadding="0" border="0"> <tr> <td colspan="2" class="hsep"></td> </tr> <tr><td colspan="2" style="height: 10px"> </td></tr> </table> <!-- Main body (Navigation, actual page content, optional news column) --> <table width="100%" cellspacing=0> <tr> <!-- Navigation --> <td style="background-color:#f0f0f0; vertical-align:top; width:20%;"> <table width="100%" cellpadding="10"> <tr> <td> <span class="fs"><b>Contents</b></span> <table width="100%" cellpadding="0" cellspacing="0"> <tr> <td class="hsep"></td> </tr> </table><p> <table width="100%"> <tr><td colspan=3><span class="fs"><a href="news.html">News</a></span></td></tr> <tr><td></td><td></td><td style="height:10px;"></td></tr> <tr><td colspan=3><span class="fs"><a href="index.html">Overview</a></span></td></tr> <tr><td></td><td></td><td style="height:10px;"></td></tr> <tr><td colspan=3><span class="fs"><a href="howtos.html">Howtos</a></span></td></tr> <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> <tr><td style="width:1%; vertical-align:top;">·</td><td colspan=2><span class="fs"><a href="howtosa0.html">Dialogs and buttons</a></span></td></tr> <tr><td></td><td></td><td style="height:10px;"></td></tr> <tr><td colspan=3><span class="fs"><a href="download.html">Download</a></span></td></tr> <tr><td></td><td></td><td style="height:10px;"></td></tr> <tr><td colspan=3><span class="fs"><a href="qa.html">Questions and Answers</a></span></td></tr> <tr><td></td><td></td><td style="height:10px;"></td></tr> <tr><td colspan=3><span class="fs"><a href="feedback.html">Bug reporting</a></span></td></tr> </table> </td> </tr> </table> </td> <td></td> <!-- Actual page contents --> <td style="vertical-align:top; width:77%;" rowspan="2"> <table width="100%" style="background-color:#f0f0f0;"> <tr><td><span class="fl"><b>Creating error correction data</b></span></td> <td rowspan="2" align="right"><img src="images/create-icon.png" alt=""></td></tr> <tr><td><i>Decision help</i></td></tr> </table><p> <!-- Insert actual page content below --> <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="passive">Yes, the medium has already been written.</a></li> <li><a href="howtos21_answer=2.html" class="active">No, but I am planning to write the medium now.</a></li> </ul> <i>How many free space is left on the medium?</i> <ul> <li><a href="howtos21_answer=3.html" class="active">The medium has more then 20% free space left.</a></li> <li><a href="howtos21_answer=4.html" class="passive">The medium is full or nearly full (less then 20% free)</a></li> </ul> You can put the error correction data <a href="howtos33.html">directly onto the medium</a>. To do so you must create an ISO image first and then augment it with error correction data before you write it to the medium. <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. <pre> </pre> <!-- do not change below --> <table width="30%" cellpadding="0"><tr><td class="hsep"></td></tr></table> <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> </td> <!-- end of page contents --> </tr> <!-- <tr valign="bottom"> <td style="background-color:#f0f0f0;"> <table cellpadding="10"><tr><td><a href="http://dvdisaster.net/legacy/en/index.html"><span class="fs"></span></a></td></tr></table> </td> <td></td> <td></td> </tr> --> </table> <!-- end of main body table --> <!-- Page footer --> <table width="100%" cellpadding="0" border="0"> <tr><td colspan="2" style="width:100%; height:10px;"></td> </tr> <tr><td colspan="2" class="hsep"></td> </tr> <tr> <td align="center"> <span class="fs"> <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. </i> </span> </td> </tr> <tr><td colspan="2" class="hsep"></td> </tr> </table> </body> </html>