Re: [Bug-ddrescue] GNU ddrescue 1.18-pre2 released

[Antonio Diaz Diaz]

Scott Dwyer wrote:
> I just did some testing, and in short, I can confirm that if read speed 
> slows down after encountering errors, even when reading another good 
> area, that closing and reopening the device does bring the read speed 
> back up where it should be. So I am confirming that it is in the kernel, 
> and not ddrescue. Although I would like to point out that for me this 
> issue does not happen when using the --direct option.

Thanks Scott. All versions of ddrescue reset skip_size when moving to a 
new area, so your findings indeed confirm thar the slowdown is not 
produced by ddrescue.


>> Do you have the "reopen" patch that I can try on my 18pre2 copy
>>     here so that I can see how the performance changes?
>
> No, I do not have a patch for ddrescue. I wrote an independent program
> for myself to test and prove the theory. Antonio will have to make any
> changes to ddrescue as he wishes.

I'll make a hacked version of ddrescue and post the URL here as soon as 
it is done. If it proves useful, a command line option can be added to 
activate the "reopen" behaviour.


Best regards,
Antonio.