dd for failing discs?

[Bernhard Voelker]

In various mailing list threads about failing discs like [1],
the advices for trying to rescue as much data as possible
always mention gnu_ddrescue, ddrescue or dd_rescue, and
often claim that plain dd is a bad choice (not in this
case).

[1] http://lists.opensuse.org/opensuse/2014-02/msg00424.html

Would it really be that bad to use something like the following?

  dd if=/dev/sda1 of=sda1.img conv=noerror iflag=fullblock

If this is true, we could add a link like
  http://www.gnu.org/software/ddrescue/
into the Texinfo manual, otherwise, we should add an example
like the above.

(AFAIK tools like ddrescue try an adaptive approach for
'ibs' values on failing sectors, and have other sophisticated
features like backup merging - admitted.)

Have a nice day,
Berny