Re: [Bug-ddrescue] ddrescue, dd_rescue and dd_rhelp

[Antonio Diaz Diaz]

Hello.

Richard Neill wrote:
> I'm slightly confused here. I've just (successfully) managed to recover 
> my read-error-prone disk with dd_rhelp, and am trying to write a quick 
> summary for my webpage. Can someone here explain to me a few things;
>
> 1)is ddrescue (GNU) related to dd_rescue:

No.

> 2)which supersedes which?

GNU ddrescue offers the functionality of dd_rescue + dd_rhelp plus some 
more.

> 3)Does ddrescue need dd_rhelp?  Does it do the same thing?

No. I have never used dd_rhelp, but I am been told that GNU ddrescue is 
less buggy and does far better accounting of errors that dd_rhelp (among 
other things).


> 4)The algorithm in the ddrescue info page isn't quite clear.
> In particular, if the file is not completely recovered, does it write 
> zeros to the places where there are damaged blocks, or is the output 
> file left with missing bits?

GNU ddrescue writes zeros to the places where there are damaged or 
non-tried blocks, but may skip non-tried blocks at the end of the file. 
In this case the output file is smaller than the input file until you 
try the last block.


Regards,
Antonio Diaz.