On Fri, 24 Sep 2004, Davis McCarn wrote:
> I fell upon SmartMonTools while searching for a low level ATA
> command utility as I would like to attempt to force failed hard disks
> to simply give me what they could.
> I also intend to test it on several Win32 systems to see if it
> is suitable for "average end users" who, unfortunately wind up holding
> the bag when there is no good reason for M$ not to have included some
> warning prior to the catastrophic failure that too often bankrupts
> small companies, literally.
> At any rate, I wanted to tender a technique I have been using
> since the 1980's to either repair bad ECC's or to confirm media
> damage. More often than not, it has also resulted in the data being
> The tool I use is Norton Diskedit; though the principle should
> work with virtually any program.
> After locating the erroring sector using another utility, I
> migrate to the location with NU in physical disk mode and after
> telling it to ignore the error, simply rewrite the sector. If the
> damage is physical, it remains an error; if it was software induced
> (i.e. system crash or power failure), the rewrite corrects the ECC and
> the error is gone. (as an aside, I now wonder whether I have caused a
> sector realocation in some cases; but those didn't exist when I first
> started using the technique)
> I do not know if this has any direct bearing on your specific
> project; but, wanted to, at least, qualify one of your assertions and,
> perhaps influence others that might encounter your project or those
> who may be working with you.
> I have seen tens of thousands of hard drives with bad sectors
> and most of them were not due to media damage. It isn't supposed to
> be possible to interrupt the drive in mid sector; but it happens
> If you have any questions or problems, please feel free to
> contact me by Email or by phone.
This is VERY useful, thank you! The number of Windows users of
smartmontools is definitely increasing and I was hoping that at some point
someone would tell us how to force sector rewrites or reallocation under
Windows. What you say above makes complete sense, as a technique to
re-write or overwrite bad sectors. The only additional thing that would
be useful to know (and perhaps NU just tells you this, and it's obvious,
so you didn't mention it) is to understand WHCIH FILE contains a given
unreadable or bad ECC block.
Would you be willing to help me revise
http://smartmontools.sourceforge.net/BadBlockHowTo.txt with information
for Windows users (or, if you prefer, write a separate short howto for
Windows)? I'd be delighted to post it, and think it would help many
people. The single most useful thing for many users would be a
'transcript' showing the operations necessary to overwrite a sector for
one example of a failed disk read.