Monitoring Linux/UNIX network traffic
The Linux sar utility can be used to monitor network traffic.
The sample output below is generated from the following command:
sar -n DEV 5
where 5 specifies a five second refresh rate.
Sample output:
07:05:35 AM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s 07:05:40 AM eth13 0.00 19100.20 0.00 1231.12 0.00 0.00 0.00 07:05:40 AM eth10 8503.20 1.00 280410.05 0.06 0.00 0.00 0.00 07:05:40 AM eth12 12662.80 11310.60 392599.48 733.85 0.00 0.00 0.00 07:05:40 AM bond0 92385.60 80866.80 2330765.89 5659.79 0.00 0.00 0.00 07:05:40 AM eth0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:05:40 AM eth1 1.00 0.00 0.11 0.00 0.00 0.00 0.00 07:05:40 AM eth2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:05:40 AM eth3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:05:40 AM eth4 9381.20 30225.00 312068.98 1948.09 0.00 0.00 0.00 07:05:40 AM eth5 22071.80 3743.20 483838.00 368.05 0.00 0.00 0.00 07:05:40 AM eth6 0.00 7364.40 0.00 476.56 0.00 0.00 0.00 07:05:40 AM eth7 0.00 1004.00 0.00 378.48 0.00 0.00 0.00 07:05:40 AM eth8 0.00 1.00 0.00 0.06 0.00 0.00 0.00 07:05:40 AM eth9 6372.60 1277.80 204399.06 82.35 0.00 0.00 0.00 07:05:40 AM lo 9210.60 9210.60 65180.86 65180.86 0.00 0.00 0.00 07:05:40 AM eth11 33394.40 6839.80 657449.78 441.19 0.00 0.00 0.00
If a port is having fixed ingress/egress throughput and the throughput column in rxKB/s or txKB/s is close to the bandwidth of the network port, the system may be network bound. See the chapter Tuning the NetBackup data transfer path for information about how to increase network bandwidth with bonding