On Mon, Jun 30, 2008 at 5:57 AM, Krishna Kumar2 <krkumar2@xxxxxxxxxx> wrote: > chucklever@xxxxxxxxx wrote on 06/27/2008 07:36:44 PM: > >> > But loopback is better than actual network traffic. >> >> What precisely do you mean by that? > > Sorry I was not clear. I meant that the loopback will be better than > actual traffic between different server/client. > >> You are testing with the client and server on the same machine. Is >> the loopback mount over the lo interface, but you mount the machine's >> actual IP address for the "network" test? > > Actually isn't that the same? I am using localhost in any case. As I understand it, "lo" is effectively a virtualized network device with point-to-point routing. Looping back through a real NIC can, in many cases, go all the way down to the network hardware and back, and is likely subject to routing decisions in your system's network layer. So I would expect them to be different in most cases. >> It would be interesting to compare a network-only performance test >> (like iPerf) for loopback and for going through the NIC. > > iperf (one thread, 64K I/O size, 30 secs): > NIC: 445 MB/s > Loopback: 735 MB/s -- Chuck Lever -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html