md5 of /dev/acd0

Bruce Cran bruce at
Mon Mar 8 23:16:53 UTC 2010

On Monday 08 March 2010 11:25:20 Christoph Kukulies wrote:
> I was trying to determine a md5sum from a DVD I had inserted into a
> FreeBSD 8.0
> on my Dell Inspiron 9400 notebook.
> I thought dd if=/dev/acd0 | md5 would work but I got "Invalid argument".
> Trying dd if=/dev/acd0 bs=1048k | md5 worked  in so far that it didn't
> yield an error
> but after the DVD stopped spinning the command  hung and I only could
> bail out using ^C.

Try using bs=2048 .

Bruce Cran

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