On Tue, 2009-07-21 at 19:31 +0200, Frans Pop wrote: > Any suggestions based on the data below? Yeah. Sorry for the delay. > Is the problem maybe that the amount of data transferred each time is so > big that the network speed becomes a bottleneck and causes the latency? > I can reproduce the issue with both a 10MBit wired link and with a 54MBit > wireless link. > > Is this a kernel bug or a configuration issue? <snip> > elrond:/david mounted on /srv/fjp/david: > > op/s rpc bklog > 0.80 0.00 > read: ops/s kB/s kB/op retrans avg RTT (ms) avg exe (ms) > 0.750 192.196 256.262 0 (0.0%) 1998.933 1999.200 > write: ops/s kB/s kB/op retrans avg RTT (ms) avg exe (ms) > 0.000 0.000 0.000 0 (0.0%) 0.000 0.000 This would be where you are losing your performance. 1998.933 ms rtt means that you are seeing a 2 second delay from the instant the RPC client pushes the request into the socket to the moment that socket receives a reply from the server. Basically, you have either a _very_ slow server, or (more likely) a networking problem. A tcpdump ought to be able to show what the problem is: whether it is the packets getting ACKed very slowly, and/or if you have dropped packet issues or if it is truly a problem with the server taking a long time to reply. Cheers Trond -- 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
