IBM System Storage TS7650G 3958 DD4, Installation Roadmap Manual

Page: 217 / 232

v Higher latency values will cause a major deterioration in throughput.
v
Packet loss should be 0%. Any other value indicates a major network problem.
Test 2: Throughput - default settings
This test checks maximal TCP throughput using a single data stream with default
TCP settings. Example result:
*** Throughput - Default TCP
[
3] 0.0-120.1 sec 2.41 GBytes 173 Mbits/sec
Interpreting the results:
v
The test ran for 120.1 seconds, transferred 2.41 GB (2.24 Gb), with an average
throughput of 173 Mbits/sec.
Note: 1 MByte = 1,048,576 bytes. 1 Mbit/sec = 1,000,000 bits/sec.
Test 3: Throughput - single stream, 1MB send buffer
This test checks maximal TCP throughput using a single data stream with a 1MB
(0.95 MiB) send buffer. Example result:
*** Throughput - 1 TCP stream(s), 1MB send buffer
[ 3] 0.0-120.0 sec 2.51 GBytes 180 Mbits/sec
Interpreting the results:
v
The test ran for 120.0 seconds, transferred 2.51 GB (2.34 GiB), with an average
throughput of 180 Mbits/sec.
v There may be an improvement here on high-latency links.
Test 4: Throughput - 16 streams, 1MB send buffer
Example result:
*** Throughput - 16 TCP stream(s), 1MB send buffer
[SUM]
0.0-121.4 sec 5.91 GBytes 418 Mbits/sec
Interpreting the results:
v The test ran for 121.4 seconds, transferred 5.91 GB (5.5 Gb), with an average
throughput of 418 Mbits/sec.
v
The extra streams yielded higher utilization of the connection.
Test 5: Throughput - 127 streams, 1MB send buffer
Example result:
*** Throughput - 127 TCP stream(s), 1MB send buffer
[SUM]
0.0-126.1 sec 8.08 GBytes 550 Mbits/sec
Interpreting the results:
v The test ran for 126.1 seconds, transferred 8.08 GB (7.53 Gb), with an average
throughput of 550 Mbits/sec.
v TCP takes a while to reach its maximal throughput. Longer testing times, 300
seconds or more, will produce more accurate results.
v
The throughput value given by this test is the potential physical throughput for
this system. It is directly affected by the available bandwidth, latency, packet loss
and retransmission rate.
Appendix G. ProtecTIER Network Performance Validation Utility for OpenStorage Systems
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