我使用iperf工具在两台相同的机器（戴尔刀片服务器M620）上对我的networking接口进行基准testing。 两者都有不同的结果。
服务器==> iperf -s -B 172.17.250.200
Server listening on TCP port 5001 Binding to local address 172.17.250.200 TCP window size: 85.3 KByte (default) ----------------------------------------
客户端在新shell ==> iperf -c 172.17.250.200 -u -il -b 250m ，
WARNING:interval too small, increasing from 0.00 to 0.5 seconds -----------------------------------------------------------
Client connecting to 172.17.250.200, UDP port 5001 Sending 1470 byte datagrams UDP buffer size: 208 KByte (default) ------------------------------------------------------------ [ 3] local 172.17.250.200 port 56853 connected with 172.17.250.200 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 0.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 0.5- 1.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 1.0- 1.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 1.5- 2.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 2.0- 2.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 2.5- 3.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 3.0- 3.5 sec 7.43 MBytes 125 Mbits/sec [ 3] 3.5- 4.0 sec 7.44 MBytes 125 Mbits/sec [ 3] 4.0- 4.5 sec 7.46 MBytes 125 Mbits/sec [ 3] 4.5- 5.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 5.0- 5.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 5.5- 6.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 6.0- 6.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 6.5- 7.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 7.0- 7.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 7.5- 8.0 sec 7.44 MBytes 125 Mbits/sec [ 3] 8.0- 8.5 sec 7.46 MBytes 125 Mbits/sec [ 3] 8.5- 9.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 9.0- 9.5 sec 7.46 MBytes 125 Mbits/sec [ 3] 9.5-10.0 sec 7.44 MBytes 125 Mbits/sec [ 3] 0.0-10.0 sec 149 MBytes 125 Mbits/sec`
在第二台机器上，我运行相同的configuration，我得到了这些结果：
服务器==> iperf -s -B 172.17.250.190
客户端在新shell ==> iperf -c 172.17.250.190 -u -il -b 250m
WARNING: interval too small, increasing from 0.00 to 0.5 seconds. ------------------------------------------------------------ Client connecting to 172.17.250.190, UDP port 5001 Sending 1470 byte datagrams UDP buffer size: 208 KByte (default) ------------------------------------------------------------ [ 3] local 172.17.250.190 port 59887 connected with 172.17.250.190 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 0.5 sec 3.00 MBytes 50.3 Mbits/sec [ 3] 0.5- 1.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 1.0- 1.5 sec 7.45 MBytes 125 Mbits/sec [ 3] 1.5- 2.0 sec 7.45 MBytes 125 Mbits/sec [ 3] 2.0- 2.5 sec 7.05 MBytes 118 Mbits/sec [ 3] 2.5- 3.0 sec 2.95 MBytes 49.5 Mbits/sec [ 3] 3.0- 3.5 sec 2.96 MBytes 49.7 Mbits/sec [ 3] 3.5- 4.0 sec 2.95 MBytes 49.5 Mbits/sec [ 3] 4.0- 4.5 sec 2.97 MBytes 49.8 Mbits/sec [ 3] 4.5- 5.0 sec 2.96 MBytes 49.7 Mbits/sec [ 3] 5.0- 5.5 sec 2.88 MBytes 48.3 Mbits/sec [ 3] 5.5- 6.0 sec 2.88 MBytes 48.3 Mbits/sec [ 3] 6.0- 6.5 sec 2.89 MBytes 48.5 Mbits/sec [ 3] 6.5- 7.0 sec 2.92 MBytes 49.0 Mbits/sec [ 3] 7.0- 7.5 sec 2.94 MBytes 49.3 Mbits/sec [ 3] 7.5- 8.0 sec 2.93 MBytes 49.2 Mbits/sec [ 3] 8.0- 8.5 sec 2.95 MBytes 49.5 Mbits/sec [ 3] 8.5- 9.0 sec 2.95 MBytes 49.5 Mbits/sec [ 3] 9.0- 9.5 sec 2.94 MBytes 49.3 Mbits/sec
为什么两台机器结果有差异，它们是相同的机器。 一台机器显示稳定的125Mbit /秒的stream量，另一台显示波动的stream量。
我也尝试在两台机器上使用ip-address'127.0.0.1'，但我仍然面临类似的问题。 在回环的情况下，我认为stream量不会通过网卡传递，但是回环也有波动。 这两台机器都运行Ubuntu 12.04 Server 64bit。 任何可能会出错的帮助将不胜感激。