Re: [Bug-ddrescue] DDRESCUE is flawed

[Scott Dwyer]

On 6/27/2015 6:12 AM, chriscooper1 wrote:
> The main purpose of the first pass is to gather as much data that is 
> readable and to skip the error areas.
>
> This does not happen and DDRESCUE spends hours on a small section 
> rather than move to a new section. Obviously the code is INCORRECT !!!
>
> I have tries most of the convoluted options available (I shall ignore 
> the fact that the options are simply ridiculous) but the same problem 
> occurs.
>
> It actually does not matter what options I have used because this 
> should not occur on a first pass.
> THE CODE IS WRONG !
Hi Chris,

First, what version of ddrescue are you using? You should be using 1.19, 
as it is the latest official stable release, and has an improved 
algorithm over previous versions.

Second, if you are using the latest version, then ddrescue is not 
flawed. Actually I wouldn't consider the older versions flawed either, 
they just don't have as good of algorithm.

Third, if your drive has that many errors, then it is going to take a 
long time to fully recover. Ddrescue can't perform miracles!

I have written an article that explains how ddrescue works, and how to 
make the most of the --skip-size option, assuming you are using 1.19.
http://www.hddoracle.com/viewtopic.php?f=172&t=1173

Ddrescue is the best free cloning tool for recovering data from a 
failing hard drive. And every recovery case is different, so you can't 
expect to get the same results as someone else.

Scott