Re: [Bug-ddrescue] Verify recovered data

[Zeniff Martineau]

I have the same issue:
* ddrescue consistently gets zero errors, yet produces a different
image every time.
* Have already made 6 images saved to 2 different HDDs with different
filesystems.
* Imaging an entire 8GB Kingston flash drive (1 image contains 3 partitions)
* ddrescue version 1.17 on Arch Linux

I thought it might be a bad flash drive...but, there are no errors in
any logs caused by the flash drive (as far as I can tell)...

Also, when I diff known files from the flash drive compared to the
mounted images, it's the flash drive which seems to have the most
correct data.

Example: A checksum contains names like "Windows" with a sensible
checksum on the flash drive, but says "Wandowc" on *some* (not all,
but same variation when they do) of the images' versions with illegal
characters in the checksum.

* Flash drive (source)'s version:
...5b6db6bdfa0c71e3ed952c48fd72249e28e11465c6eb4fba49a41c  ./Windows...
* Some, but not all, images made by ddrescue wrote this:
...5b6tb6bdfa0c71e3ed952s48fd72249e28e11465c6eb4fba49a41c  ./Wandowc...
(Note the "t" and "s" in the checksum...)

There are dozens of files with multiple small variations in data just like this.

Questions:
1. If this is a bad flash drive, why is it reading files correctly
with no errors, but only the images are bad?
2. If this is a bug in ddrescue, what can I do to help it get resolved
or what can I do for a workaround (I want to create an exact and
verifiable copy of the drive)?
3. If there is no workaround for this, is my best bet to just use
rsync to copy the files and forget about making an image?
4. Is there some way to merge the images to create a more correct
version, similar to the multiple bad CDs example from the docs? (can't
really use the doc example, though, because no ddrescue logs contain
errors)


Thank you and have a great day~!!! ^^

P.S. Sorry to reply to an older message. It's my 1st mailing list post
and this unreplied-to message by matt456 from 2013-03-03 matches my
problem exactly and I can't find any other info after searching all
day.