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From: Doug Hardie <bc979@lafn.org>
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Subject: Verifying a DVD
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I am periodically backing up a bunch of files to DVD.  I use mkisofs to =
create the original image and growisofs to write it to a real DVD.  =
However, at that point I want to verify that the write was successful.  =
I tried using dd to read back in the DVD to a file.  Its interesting =
that the bs parameter must be at least 2048 or dd complains about a =
parameter error.  However, the big issues is that the original image =
file is shorter than the read file.  The difference is 10240  bytes.  =
This difference is the same for bs 2048, 10240, or 102400.  It appears =
that dd is adding one last block.  Is there a way to prevent this or =
remove that block?=