Re: Support alternative output image formats?

[Antonio Diaz Diaz]

Hi Christian,

Christian Franke wrote:
> Are there any plans to support other output formats than raw images?

No, really.

> AFF is a segmented format which supports compression, encryption and
> signing. Using it instead of raw images could significantly reduce the
> size of output images if the disk contents is compressible.

It is not possible to compress data out of order. Even if you compress each 
cluster or sector separately as they are read, you can't store them in a 
single file in order because you can't know how much space will require each 
compressed gap in the file corresponding to the sectors being skipped.

Therefore, the only way of creating a compressed image (or an AFF image) 
using ddrescue is to create a normal image first, and then compress (or 
convert) that image.

> OT: Recently I had a very interesting real word testcase for ddrescue:
> A 4TB Seagate ST4000NM0265 with massive seek problems could be
> completely recovered by running ddrescue (Cygwin) for about two weeks
> 24x7, except for one single sector. Required changing ddrescue
> parameters several times and reduction of disk's own ERC time (with
> smartctl).

Interesting indeed. Thanks.

Best regards,
Antonio.