In message <20000525212934.A203@antioche.eu.org>, Manuel Bouyer writes:
>I usually use the raw device but I would expect this to work as well ...

Apparently, it doesn't.  I'm used to using BSDI for dups, and there, plain
old sr0a works fine.

>Did you try 'dd if=/dev/cd0a of=cd bs=2k' ? If that works it could give an
>interesting point.

Same results.  I understand vaguely that the raw device gets this right,
but the explanation of the behavior I get escapes me; if I got four copies
of each 512-block, I would understand, but I get four copies of each
2048-block.

-s