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Date:      Fri, 19 Nov 2010 19:39:00 +0100
From:      Matthias Apitz <guru@unixarea.de>
To:        Hans Petter Selasky <hselasky@c2i.net>
Cc:        freebsd-usb@freebsd.org
Subject:   Re: copying /dev/da0 with dd(1) to file: output differs
Message-ID:  <20101119183900.GA1221@tiny.Sisis.de>
In-Reply-To: <201011191916.53655.hselasky@c2i.net>
References:  <20101119143337.GA3023@current.Sisis.de> <201011191821.09308.hselasky@c2i.net> <20101119173519.GA3933@current.Sisis.de> <201011191916.53655.hselasky@c2i.net>

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El día Friday, November 19, 2010 a las 07:16:53PM +0100, Hans Petter Selasky escribió:

> > I was thinking in a tool just reading each file block by block,
> > comparing the blocks and noting the 1st diff with block offset number.
> > (some 10 lines of C code :-))
> > 
> > 	matthias
> 
> Maybe you need to write a small C-program to do that.
> 
> You can use bcmp() to compare two buffers.

Will do that tomorrow.

Just an idea: The USB key in question was new and I only created the
file system on it the usual way (fdisk, bsdlabel, newfs). Then I
restored the dump on it (which took 26 hours for 3.1 GByte dump file).
The USB key boots fine, btw. 

Could it be that unwritten/unformatted blocks are read as random data
from that USB key? Should I overwrite the full USB key from /dev/zero?

	matthias

-- 
Matthias Apitz
t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211
e <guru@unixarea.de> - w http://www.unixarea.de/



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