rhel6/7: problem with network statistics reported by sysstat
Issue
-
The net statistics reported by the sar application are wrong, more than twice the real traffic. You can see in the following copy-n-paste the big difference between the statistic reported from sysstat in the RPM repository:
Average: IFACE rxpck/s txpck/s Average: bond0 11342.37 16948.02
Sysstat compiled from sources shows lower values, which also match the values reported by
ifconfig
:
and the statistics reported by sysstat compiled from sources:# ifconfig bond0 | egrep -o 'RX packets:[0-9]+' # sleep 5 # ifconfig bond0 | egrep -o 'RX packets:[0-9]+' RX packets:16831578535 RX packets:16831599072
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The values of rxpck/s and txpck/s of sar increased even though the number of packets /proc/net/dev showed was not increasing:
12:00:01 AM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s : 11:50:01 AM qvo1 0.55 0.40 0.05 0.05 0.00 0.00 0.00 11:50:01 AM lo 14.38 18.38 0.94 0.94 0.00 0.00 0.00 11:50:01 AM tap1 0.55 0.40 0.05 0.05 0.00 0.00 0.00 11:50:01 AM eth_2 23282939.17 72342.13 43105104.33 9231.02 0.00 0.00 80234.34 ^^^^^^^^^^^^^^^^^^^^^
The raw values in /proc/net/dev make sense, but the values from sar do not. What is the reason?
Environment
- Red Hat Enterprise Linux 6 and 7
- sysstat, versions <11.3.2
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