growisofs will overwrite a DVD+RW when run non-interactively iff you use the option "-use-the-force-luke". Heh. Read the source for details.

To make a bootable FreeBSD CD, it's not enough to simply dd of=iso and burn that. Do this instead:

mkisofs -R -b boot/cdboot -no-emul-boot -o foo.iso /tree/to/copy

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