>Then a quad counter counting bytes will wrap after
>18446744073709551616/10485760=1759218604441.6 seconds.

Minor correction, this requires a u_quad_t counter, quad_t will
overrun in a mere half million years or so. :-)

10 MB/s is a low figure for projecting into the future, but
even a couple of orders of magnitude are not a big deal here,

Chris