[Tfug] Drive recovery

[Bexley Hall]

--- On Thu, 6/4/09, Harry McGregor <micros at osef.org> wrote:

> Bexley Hall wrote:
> > --- On Wed, 6/3/09, Bowie J. Poag <bpoag at comcast.net>
> wrote:
> >
> >> dd is completely unaware of what a sector is -- It's completely 
> >
> > My bad, I didn't expect to be taken literally.  :-(
> > s/when the sector(s) in question return read errors/when a read(2)
> > encounters the defective sectors and returns an error/
>
> <snip>
> 
> This is the reason I suggested dd_rescue instead of dd.
> 
> dd will barf with i/o errors, dd_rescue will continue reading.

-----^^^^^^^^^

Do you know this to be true?  I have never tried using dd(1)
on defective media.  :<  I suppose I could set up a logic
analyzer to deliberately botch a specific disk read(2) to
see for myself... but, that;'s a lot more work than my current
level of curiosity would warrant!  ;-)

> There is also GNU ddrescue (not the same as dd_rescue), and
> it does a good job too.
> 
> http://www.gnu.org/software/ddrescue/ddrescue.html
> 
> http://www.garloff.de/kurt/linux/ddrescue/

Presumably, if such tools exist, then dd(1) *must* not be
up to the task...