dd errors with certain DVDs

[Paul Smith]

On 3/25/07, Charles Curley <charlescurley at charlescurley.com> wrote:
> > I am getting the errors below when I execute the command
> >
> > dd if=/dev/dvd of=dvd1.iso
>
> DVD/CD buring software does wierd things so that you cannot always
> depend on reading the whole thing without an error message.
>
> To see if you got all of it, mount your iso as a loopback device:
>
> mkdir foo
> mount dev1.iso foo
> mount /dev/dvd /media/<device> # as appropriate
>
> Then diff the two:
>
> diff -r --brief /media/<device> foo
>
> If the result is silent, you have all the data you need.
>
> To answer your other email, you can validate a freshly minted DVD
> similarly.

Thanks, Charles. Yes, it was the error regarding dd that was causing
the md5sums mismatch (reported in the other post of mine). However,
the method that you suggest works fine, and my problem is solved. The
command dd is not very reliable, indeed.

Paul