[CentOS] Bonding performance question

Tue Jan 11 13:41:39 UTC 2011
lhecking at users.sourceforge.net <lhecking at users.sourceforge.net>

 I have a Dell server with four bonded, gigabit interfaces. Bonding mode is
 802.3ad, xmit_hash_policy=layer3+4. When testing this setup with iperf,
 I never get more than a total of about 3Gbps throughput. Is there anything
 to tweak to get better throughput? Or am I running into other limits (e.g.
 was reading about tcp retransmit limits for mode 0).

 The iperf test was run with iperf -s on the server, and iperf -c server
 on four clients connected to the same switch.

------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local 10.10.15.193 port 5001 connected with 10.10.15.184 port 48588
[  5] local 10.10.15.193 port 5001 connected with 10.10.15.187 port 49231
[  6] local 10.10.15.193 port 5001 connected with 10.10.15.188 port 53197
[  7] local 10.10.15.193 port 5001 connected with 10.10.15.189 port 55309
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  1.10 GBytes   941 Mbits/sec
[  5]  0.0-10.0 sec   872 MBytes   728 Mbits/sec
[  6]  0.0-10.0 sec   318 MBytes   267 Mbits/sec
[  7]  0.0-10.0 sec  1.10 GBytes   939 Mbits/sec
[  8] local 10.10.15.193 port 5001 connected with 10.10.15.184 port 48589
[  4] local 10.10.15.193 port 5001 connected with 10.10.15.187 port 49234
[  5] local 10.10.15.193 port 5001 connected with 10.10.15.188 port 38864
[  6] local 10.10.15.193 port 5001 connected with 10.10.15.189 port 55311
[  8]  0.0-10.0 sec  1.10 GBytes   941 Mbits/sec
[  4]  0.0-10.0 sec   862 MBytes   721 Mbits/sec
[  5]  0.0-10.0 sec   322 MBytes   270 Mbits/sec
[  6]  0.0-10.0 sec  1.10 GBytes   939 Mbits/sec



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