There's no reasonable situation where there will be one there, except if the
disk had data on it previously for some reason. It's significantly more
likely (read "the world until UFS2 was merged") that sector 0(..15)
contains really important stuff like boot blocks and disk labels.
Once again, I ask, why wasn't UFS2 implemented as a separate file
system a la lfs & ext2fs ?
It could have shared a chunk of the kernel code (just like those),
and had different userland tools and a different fs_type.
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