"J. P. Gilliver (John)" wrote in
:

A much better approach to data recovery is to clone the drive, sector
by sector, using a utility that understands how to work around bad
media. Two examples are ddrescue and dd_rescue, both freeware.

How do they handle bad sectors though? Just give them a default value?


From what I could see, a log file lists locations and the copy may have some
arbitrary value, whatever was already in that space. So long as the log file
maps what is knowm to be recovered, it also knows what is not, so it's not
relying on whatever is in the unwritten area of the copy.

I don't think they fix the disk or mark bad sectors (if so, I missed that), I
think they just copy areas that look good, like doing the easy chunks of a
jigsaw first, and map out a pattern indicating what is not yet done. Ideally,
I think they never write to the source disk at all.