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

[Scott Dwyer]

Hi David,

First, did you see my reply with my 2 cents? It contained some info (my 
opinion) as to what might have happened to your drive, and what you 
might expect (from my experience). I only replied to the bug list, so if 
you did not see it then you will have to look into the archives which 
can be found through the ddrescue page.
http://lists.gnu.org/archive/html/bug-ddrescue/

Second, while errors are skipped, every error takes time to process, 
first by the drive itself and then that is multiplied by any op system 
retries (from what I can tell in linux from observation, it is about 15 
retries normally, or 5 retries using the direct option). So if the drive 
takes 3 seconds per error, then it would take 15 seconds with the direct 
option to process the error, or 45 seconds without the direct option. I 
used 3 seconds for the drive as that is about an average from a few 
drives I have seen, but that is dependent on the drive itself. Doing a 
little math on that means that at 15 seconds per error, you could 
process about 5760 errors per day. And you are going to have a LOT of 
errors by the looks of it, so you are in for a long recovery. But don't 
be too discouraged just yet. You will have many errors spread all over, 
but there is still a chance that you will end up with 99% of good 
sectors vs bad, not to say that file recovery will be easy when done. 
What file system is this? Is is NTFS? What type of files will you be 
trying to recover?

Third, I am interested in a copy of your logfile if possible. Actually I 
would like the first one you sent to Antonio if you still have it, and 
also your current one.

Scott


On 2/3/2014 5:00 PM, David Deutsch wrote:
> 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).
>
> 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?