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AIX Versions 3.2 and 4 Performance Tuning Guide

Using netpmon to Evaluate Network Performance

The netpmon command uses the trace facility to obtain a detailed picture of network activity during a time interval. Since it uses the trace facility, netpmon can be run only by root or by a member of the system group.

In AIX Version 4, the netpmon command is packaged as part of the Performance Toolbox for AIX. To determine whether netpmon is available, use:

lslpp -lI perfagent.tools

If this package has been installed, netpmon is available.

Tracing is started by the netpmon command, optionally suspended with trcoff and resumed with trcon, and terminated with trcstop. As soon as tracing is terminated, netpmon writes its report to stdout. The following sequence of commands gives a simple example of netpmon use:

# netpmon -o nm.test.out ; ping xactive 256 5 ; trcstop

The report (somewhat condensed) produced by this sequence, in an otherwise idle system, was:

Wed Jan 12 14:33:25 1994
System: AIX alborz Node: 3 Machine: 000249573100
4.155 secs in measured interval
========================================================================
Process CPU Usage Statistics:
-----------------------------
                                                   Network
Process (top 20)             PID  CPU Time   CPU %   CPU %
----------------------------------------------------------
ping                       12699    0.0573   1.380   0.033
trcstop                    12700    0.0150   0.360   0.000
ksh                        13457    0.0150   0.360   0.000
rlogind                     6321    0.0127   0.306   0.088
netpmon                    12690    0.0064   0.153   0.000
netw                         771    0.0047   0.113   0.113
netpmon                    10650    0.0037   0.090   0.000
trace                      10643    0.0023   0.055   0.000
swapper                        0    0.0022   0.053   0.000
writesrv                    1632    0.0009   0.021   0.000
----------------------------------------------------------
Total (all processes)               0.1201   2.891   0.234
Idle time                           3.8904  93.639
========================================================================
First Level Interrupt Handler CPU Usage Statistics:
---------------------------------------------------
                                                   Network
FLIH                              CPU Time   CPU %   CPU %
----------------------------------------------------------
external device                     0.0573   1.379   0.890
data page fault                     0.0368   0.887   0.000
floating point                      0.0001   0.003   0.000
----------------------------------------------------------
Total (all FLIHs)                   0.0943   2.269   0.890
========================================================================
Second Level Interrupt Handler CPU Usage Statistics:
----------------------------------------------------
                                                   Network
SLIH                              CPU Time   CPU %   CPU %
----------------------------------------------------------
clock                               0.0415   0.998   0.000
tokdd                               0.0064   0.154   0.154
<addr=0x00022140>                   0.0008   0.019   0.000
----------------------------------------------------------
Total (all SLIHs)                   0.0486   1.171   0.154
========================================================================
Network Device-Driver Statistics (by Device):
---------------------------------------------
                 ----------- Xmit ----------   ----- Recv ----
Device           Pkts/s  Bytes/s  Util  QLen   Pkts/s  Bytes/s
--------------------------------------------------------------
/dev/tok0          3.37      629 0.005 0.005    16.85     1900
========================================================================
Network Device-Driver Transmit Statistics (by Destination Host):
----------------------------------------------------------------
Host                     Pkts/s  Bytes/s
----------------------------------------
xactive.austin.ibm.com     1.44      390
========================================================================
Detailed Second Level Interrupt Handler CPU Usage Statistics:
-------------------------------------------------------------
SLIH: tokdd
count:                  84
  cpu time (msec):      avg 0.076   min 0.058   max 0.097   sdev 0.009  
========================================================================
Detailed Network Device-Driver Statistics:
------------------------------------------
DEVICE: /dev/tok0
recv packets:           70
  recv sizes (bytes):   avg 112.8   min 68      max 324     sdev 75.2   
  recv times (msec):    avg 0.226   min 0.158   max 0.449   sdev 0.056  
xmit packets:           14
  xmit sizes (bytes):   avg 186.6   min 52      max 314     sdev 100.0  
  xmit times (msec):    avg 1.552   min 1.127   max 2.532   sdev 0.380  
========================================================================
Detailed Network Device-Driver Transmit Statistics (by Host):
-------------------------------------------------------------
HOST: xactive.austin.ibm.com
xmit packets:           6
  xmit sizes (bytes):   avg 270.3   min 52      max 314     sdev 97.6   
  xmit times (msec):    avg 1.772   min 1.516   max 2.532   sdev 0.346 

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