Filesystem marker.

[M. Warner Losh]

In message: <16389.25821.502399.872877 at canoe.dclg.ca>
            David Gilbert <dgilbert at dclg.ca> writes:
: Is there a set of bytes at some offset in a block that is common to
: any instance of a BSD ufs filesystem?  I ask because recently my home
: machine erased it's fdisk block _and_ the bsdlabel with it.  It
: certainly didn't have time to erase the whole disk, but I'm having
: trouble guessing where the partitions are.

You can look for the UFS magic number.

Warner