dvdisaster Version 0.72.4 / 0.72 (pl4) | To the Internet version

Contents

News
Overview
Howtos
· | The big picture
| - | error correction
| - | correct usage
| - | incorrect usage
· | Scanning media for errors
· | Putting error correction data on a separate file
· | Putting error correction data on the medium
· | Recovering media images
· | Getting information about images and error correction data
· | Testing image compatibility
· | Dialogs and buttons
Download
Questions and Answers
Bug reporting

### Using dvdisaster the wrong way

Joe bets on his media keeping their content without additional protection.

10. Feb. 2004 |  |  | Joe creates two CDs containing important data. But he does not make any provisions against data loss on those media.

14. May 2005 |  |  | Joe uses his CDs regularly. After one year they are still perfectly readable.

19. Aug 2007 |  |  | After two more years Joe notices that some data on one CD is no longer readable.
scanning |  |  |
20. Aug 2007 |  |  | Joe downloads dvdisaster and performs a read error scan. He finds out that the CD contains 25000 unreadable sectors. A scan of the second CD reveals that it has developed 1500 unreadable sectors gone unnoticed so far.
reading |  |  |
21. Aug 2007 |  |  | Joe uses dvdisaster to read as much sectors as possible from the defective media. But since he does not have error correction data there is no way of recalculating the unreadable sectors.
many reading attempts |  |  |
05. Sep 2007 |  |  | Joe takes advantage of dvdisaster's feature to complete images through multiple reading passes. He moves the defective images to several computers to perform reading attempts with different drives. After two weeks of trying at least all missing sectors from the second CD have been read. However on the first CD still 21000 sectors remain unreadable by any drive he tried.
only one CD recovered |  |  |
06. Sep 2007 |  |  | Joe dismisses the first CD as unrecoverable and considers himself lucky to have a complete image from the second CD again. However if he had created error correction data in time, he'd probably 1) saved two weeks of reading attempts and recovered the contents from both CDs.

1)The error correction assumes a typical aging process. If the CD gets severely damaged it becomes unrecoverable even with error correction data. Do not rely on dvdisaster alone for protecting important data; instead employ additional measures like creating additional copies on different types of media.

Copyright 2004-2012 Carsten Gnörlich. Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.