4 replies to this topic

[Nuno Brito]

The dvdisaster project:

CD and DVD media keep their data only for a finite time (typically for many years). After that time, data loss develops slowly with read errors growing from the outer media region towards the inside.


Archival with data loss protection

dvdisaster stores data on CD/DVD (supported media) in a way that it is fully recoverable even after some read errors have developed. This enables you to rescue the complete data to a new medium.

Data loss is prevented by using error correcting codes. Error correction data is either added to the medium or kept in separate error correction files. dvdisaster works at the image level so that the recovery does not depend on the file system of the medium. The maximum error correction capacity is user-selectable.

http://dvdisaster.sourceforge.net/en/

I haven't tried it (yet) but it seems a very good professional level free alternative to ISO buster and help recovering back scratched DVD's with priceless photos or documents inside..

[was_jaclaz]

a very good professional level free alternative to ISO buster and help recovering back scratched DVD's with priceless photos or documents inside..

hmmm, don't think so:
http://dvdisaster.sourceforge.net/en/

Common misunderstandings about dvdisaster:
dvdisaster can not make defective media readable again. Contents of a defective medium can not be recovered without the error correction data.

From what I've seen it is a FREEWARE alternative to Arrowkey/Infinadyne Accuburn-R a Commercial program that makes sure that data is properly written to optical media.
http://www.infinadyn...accuburn-r.html

Actually it appears that dvdisaster works more with redundant checks in a way similar to .par data files do with respect with .rar (or similar) archives.

http://dvdisaster.so...en/index30.html

Limitations of using dvdisaster:
Error correction data must be created before the medium fails, preferably at the same time the medium is written.

Error correction data requires additional storage space either on the protected medium or by using additional media. Using the standard settings the additional storage space amounts to 15% of the original data size (approx. 700MB for a full 4.7GB DVD).

no guaranteed protection against data loss.

The advantage that Accuburn-R sports is the fact that data correction is done WHILE writing on the optical media, if needed re-writing the parts appearing to be defective.

As I see it, the 15% more space occupied by dvdisaster, but I recall using Accuburn-R with CD's at work and the increased amount of space taken was in the same order of magnitude is a big trade-off, is only worth it for "real" long-term backups, which should be ANYWAY be kept with great care and avoiding scratches.

However, being "normal" burning apps, expecially in combination with particular brands/manufacturers of media, more or less "untrustworthy", unless you manually verify with another program like CDCHECK the actual readability of the burmed CD, having a safer FREEWARE app is a good thing.

There is also a positive "side-effect" use for it when trying recovering a "normal" scratched CD by means of manually polishing the surface with Brasso or similar compounds, the "mapping" of the unreadable sectors makes it easier to understand (roughly) where more polishing is needed:
http://www.msfn.org/..._CD_t56005.html

jaclaz

[Nuno Brito]

I see you have some experience on this area, now I understand that my idea of where to use this program was not right - thanks for explaining!

Fun time reading some of the clues you've also gaven here: http://www.msfn.org/...p...st&p=412182

[was_jaclaz]

Fun time reading some of the clues....

Yep, I already had some reports about the "Vodka trick" to be really effective

jaclaz

[Mikorist]

One more free data "recovery" software:
(Available for Windows and Linux)

Unstoppable Copier

"Recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts were not recoverable in the end."

http://www.roadkil.net/unstopcp.html

"As the CD's contents are preserved, a scratched CD can be recovered by polishing its plastic surface. If, after carrying out the above cleansing, the CD persists in giving reading errors, just polish the CD with toothpaste. That's right, toothpaste. It works wonders, and you won't spend a fortune buying professional cleaning kits. Polish the scratches with a cotton swab, rubbing gently the paste-imbued swab over the scratches until they disappear or until you notice that you have removed them as far as possible. Sometimes the paste may cause new scratching, but it will be merely superficial and easily removed. After clearing the scratches, wash the CD in water.

If there are still scratches that the toothpaste has not managed to removed, use a metal polish (Brasso) in the same way as described above. Finally, rub Vaseline on the CD, very gently (do not press hard), from moving out from the centre to the rim."

from: http://www.hardwares....com/article/77



Mikorist