Re: [Bug-ddrescue] Feature Suggestion: Automatic Cooldown mode

[Antonio Diaz Diaz]

David Deutsch wrote:
> Quick update - Seems like speed is indeed improving (slightly redacted
> for space):

It is nice that speed is improving now, but the gain I was thinking 
about was a sustained speed for a longer time before trimming.


> Close to breaking 1750GB, too. I think this kills the "1/8 of the disc
> is dead" idea, ie. one platter/side or read head being dead. Still
> curious what could produce such a regular error, though. Particularly
> across the entire space of the disc. Or maybe I just have no frigging
> clue how hard discs werk (I really don't).

To make things difficult, most probably every disc works differently. :-)


> Reading still progresses in a steady pace in general, although it's
> kind of weird: It only reads every two to three minutes, sometimes up
> to ten. Not sure whether that is the drive hardware failing more, in
> general (though speeds improving would say otherwise) or just the
> general issue with bad sectors. Then again: Shouldn't it just skip
> past those? Or are the sectors around the bad ones just hard to get
> anything out of?

The sectors around the bad ones are hard to get out of.


> This is what it looks like now in ddrescueview, btw:

I am just now testing an idea inspired by your images; making each 
copying pass run in the inverse direction as the previous one. This 
should read faster all those large non-tried areas remaining behind the 
large errors.

In case you feel like trying reverse mode, take into account that 
reversing direction in the middle of a rescue is tricky. (It continues 
backward from the current position, not from the end). The following 
sequence makes the trick:

  ddrescue your_options_and_files -i position -s 512
  ddrescue your_options_and_files -R


Best regards,
Antonio.