As an alternative to all of the above, consider UDPCast. It's point is that it can multicast; but it is also great for point-to-point copies. I adds its own reliability layer, so don't be scared of UDP in the name. It can rate limit, if you want. I've used it to great effect to shuffle a lot of GB to a bunch of servers at the time.

Way down at a low level, the network hardware/firmware knows how to send data 1:N. Using that is a single easy command away, but hardly anyone knows it.

http://kylecordes.com/2008/multicast-your-db-backups-with-ud...