Re: [bug-ddrescue] Improvement: Avoid rescuing empty space

[Antonio Diaz Diaz]

Hi Robert,

Robert Heel wrote:
> Thanks for the great project, it saved many bytes :-)

You are welcome! :-)

> Huge HDDs are often not completely used, and the unused space is often
> filled with zeros.
> What about a config option to skip sectors filled with zeros (in the
> same way skipping bad sectors) to avoid wasting time rescuing empty space?

As Robert Trevellyan points out, ddrescue already provides the option 
'--domain-mapfile'. All you need to do is to create a domain mapfile with a 
tool like partclone[1], and pass it to ddrescue using --domain-mapfile.

Of course, for this to work, the file system must not be (too) corrupt, or 
partclone won't be able to create the domain mapfile.

[1] https://partclone.org/features/

Hope this helps.

Merry Christmas,
Antonio.