AIX 5L Problem Determination - IBM Redbooks

The count values are summarized since system startup:
The Mtu column Maximum transmission unit; the maximum size of packets
in bytes that are transmitted using the interface
The Ipkts column Total number of packets received
The Ierrs column Total number of input errors; for example, malformed
packets, checksum errors, or insufficient buffer space in
the device driver
The Opkts column Total number of packets transmitted
The Oerrs column Total number of output errors; for example, a fault in the
local host connection or adapter output queue overrun
The Coll column Number of packet collisions detected
Tuning guidelines based on netstat -i
If the number of errors on input packets is greater than one percent of the total
number of input packets (from the command netstat -i), that is:
Ierrs > 0.01 x Ipkts
Then run the netstat -m command to check for a lack of memory.
If the number of errors during output packets is greater than one percent of the
total number of output packets (from the command netstat -i), that is:
Oerrs > 0.01 x Opkts
Then increase the send queue size (tx_que_size) for that interface. The size of
the tx_que_size could be checked with the following command:
# lsattr -El adapter
If the collision rate is greater than 10 percent, that is:
Coll / Opkts > 0.1
Then there is a high network utilization, and a reorganization or partitioning may
be necessary. Use the netstat -v or entstat command to determine the
collision rate.
The netstat -i -Z command
The netstat -i -Z command clears all the statistic counters for the netstat -i
command to zero.
Chapter 10. Performance problem determination 267