On Fri, Sep 24, 2010 at 12:37 AM, <cpol...@surewest.net> wrote: > What's going on over the wire? > Something wiresharky: Statistcs -> TCP stream graph -> > throughput graph. Might be revealing.
I was running iftop to get a handle on what's going on over the wire. Not as in depth as wireshark, but it gives me a graph and a more data to start with. I ran it on the desktop receiving information from the FPGA and the data server receiving data from the desktop. On the desktop: - FPGA pushes data at a constant 4.76MB/sec, desktop receives that just fine, no burstiness. - The desktop seems to push data to nfs at anywhere from the 14.6Mb/sec to 29Mb/sec - The desktop receives NFS data at about 22.7Mb/sec constant (sometimes it jumps to 24.7Mb/sec, but its rare) On the server: - Server is sending NFS data to desktop at 22.6Mb/sec (I'm not going to sweat over .01Mb/sec difference) - Server is receiving NFS data with the same kind of bursts. It seems like the burstiness continues, but the dropped packet rate reduces dramatically if the following are set: /sbin/sysctl net.core.rmem_max=33554432 /sbin/sysctl net.core.wmem_max=33554432 /sbin/sysctl net.ipv4.tcp_rmem="4096 87380 33554432" /sbin/sysctl net.ipv4.tcp_wmem="4096 65536 33554432" /sbin/sysctl net.ipv4.tcp_no_metrics_save=1 which points to issues with the TCP stack. Is NFS over UDP worth trying, or am I going to run into similar things, except not with TCP retransmit but with NFS UDP retrainsmit? _______________________________________________ Tech mailing list Tech@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
