Re: dd / netcat / md5sums: hashes do not match

From: solana (solana_nexus_at_hotmail.com)
Date: 09/18/03 

Date: 18 Sep 2003 14:52:19 -0700

bugs@pu.net (Mark Hittinger) wrote in message news:<2bkab.380172$Oz4.158779@rwcrnsc54>...
> Casper H.S. *** <Casper.***@Sun.COM> writes:
> >>B# nc -l -p 6789 | dd of=./hda1.img bs=512 conv=noerror,sync
> >>A# dd if=/dev/hda1 bs=512 conv=noerror,sync | nc <B's IP> 6789
>
> >I wouldn't use "sync" because sync causes blocks to be
> >padded with NULLs; this is certain to corrupt
> >the file.
>
> If his hard drive has a bad spot you need sync to fill the bad read with
> nulls. If you don't do this then the blocks on the output side will be
> mis-aligned after the bad spot.
>
> Now that we know he's doing this on a live file system I guess the mystery
> is solved.
>
> Later
>
> Mark Hittinger
> bugs@pu.net

new update on this one.. whole reason i needed to do this was b/c the
system was a vmware image and i couldnt really take it offline and
separately mount it.. well, i figured out how to get by that (mount
the partition as a 2nd part. within a separate vmware session) so the
md5s dont change since no changes occur to the original partition
anymore.

the different dd stats dont matter.. md5s match now between A parts.
and the file on B.

thanks for your tips anyway!

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