NAME¶

ethbw

ethbw reports the total data moved per RDMA NIC over each interval (default of 1 second). The bandwidth reported for each interval is in units of MB (1,000,000 bytes) over the interval. Both transmit (xmt) and receive (rcv) bandwidth counters are monitored. ethbw also monitors Intel NICs for any RDMA retransmit or input packet discards, in which case, the xmt or rcv, respectively, is shown as red. The data is gathered via data movement counters in /sys/class/infiniband.

The following cases may present the need to improve PFC tuning:

1)

Retransmits can represent packet loss or corruption in the network and may indicate opportunities to improve PFC tuning or high bit error rates (BER) on some cables or devices.

2)

Input packet discards indicate packets the NIC itself dropped upon receipt. This can represent opportunities to improve PFC tuning but can also be normal for some environments. Retransmits at the remote NICs that are communicating with this NIC are a more powerful indicator of PFC or BER causes for packet loss.

Syntax¶

ethbw [-i seconds] [-d seconds] [ nic ... ]

Options¶

--help

Produces full help text.

-i/--interval seconds

Specifies the interval at which bandwidth will be shown. Values of 1-60 allowed. Defaults to 1.

-d/--duration seconds

Specifies the duration to monitor. Default is infinite.

nic

Specifies an RDMA NIC name. If no NICs are specified, all RDMA NICs will be monitored.

Examples¶

ethbw

ethbw irdma1 irdma3

ethbw -i 2 -d 300 irdma1 irdma3