> This thread got me thinking about all the unix systems I've used, admin'd, and fought with over the years, and I suddenly remembered a system I used the early 90s when you couldn't mv a file across filesystem boundaries because what that actually was was really a copy-and-remove and not just a rename, so it was outside mv's domain.

Many similar problems like that is exactly the reason why many systems had GNU tools installed; and "GNU's Not Unix!".