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Date: Sun, 8 Feb 2009 16:30:29 -0800 (PST)
From: Morph Ex <morphex9 AT yahoo DOT com>
Subject: dd in cygwin vs dd in linux - number of records is always different
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I'm trying to use "dd" to create a md5 checksum of a dvd.  The problem is that the number of records read by "dd" is always different depending on the OS used.  For example, using the same command below in both cygwin and linux displays the following results.

dd if=/dev/scd0 bs=2048 iflag=direct | md5sum -b

Linux (ubuntu 8.10 amd64)
28446caccede349759e4e9fed8bce862 
3025539+0 records in 
3025539+0 records out 
6196303872 bytes (6.2 GB) copied, 3347.83 s, 1.9 MB/s 
 
Cygwin (windows xp pro)
15cab8963c4746eca21c014224adefa3 
3025538+0 records in 
3025538+0 records out 
6196301824 bytes (6.2 GB) copied, 3323.91 s, 1.9 MB/s


For some reason there is always 1 less record read in cygwin.  I've tested numerous dvds and they all end up being 1 record less in Cygwin than the Linux results.  Why is this happening?  Is there any way to force "dd" to skip 1 record at the very end of the dvd?



      


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