In case of any severe data loss situation, the user would need to know about the ddrescue tutorial. Indeed, ddrescue is a raw drive imaging software application that “copies information from a file or block device to some other, trying hard to rescue information in case of read errors.” This software application is written while keeping the UNIX / LINUX operating systems in mind and it is developed as a part of the GNU project.
Ddrescue and dd_rescue are completely different software applications and these does not share any similarities in the development as well. These two software (s) are not associated in almost any way except they both effort to boost the standard dd software tool and coincidentally selected equivalent names for their unique 
programs.
Automated merging of backups: If you have atleast two or more than two damaged copies of any file or CD-ROM and use the ddrescue tutorial to run the application on all of them, you may possibly get an absolute error free output file. This really is so because the likelihood of getting wrecked areas at the similar places on different input data is really low. Utilizing the log file, merely the required blocks are read from the 2nd and successive copies.
The following video will help you out in making a better idea about the ddrescue tutorial.
