Originally posted by: luverofpeanuts
Hi Tim,
For iPerf you need the 'server' side active as well.
Test for transfer from Server A to Server B
1) On Server B (the one that transfers back slowly), run this command 'iperf -s' (this will run the iperf in 'server' mode, and wait for client connections).
2) On Server A then, run 'iperf -c <ipaddress of server B>' to run the test. It defaults to 10 seconds.
Test for transfer from Server B to Server A
1) On Server A, then, do 'iperf -s',
2) On server B, do 'iperf -c <ipaddress of server A>'.
Summarizing what information you've provided so far. (?? note questions)
1) MTU sizes are all 1500 -- Good
2) Server A is LPAR with largesend enabled, uses virtual ethernet
3) VIOS has plenty of CPU and memory, and SEA w/large send enabled, and uses 3 port etherchannel w/802.3ad mode. (?? 10 Gbps ethernet?)
4) Server B does not use VIOS, but uses a NIB configuration for ethernet, meaning 1 active 10 Gbps port, with 1 backup 10 Gbps port.
5) Server B transfers slowly, and other server(s) transfer back quickly.
In your original post you asked "Does anyone know how to check problem with server A", but given the information you've provided and if I understand correctly, it seems to me like the problem is really more likely at Server B (the one that transfers back slowly). Does that make sense to you?
More questions.... On server B,
1) For the active and backup 'ent' devices that are a part of the etherchannel adapter, issue this command 'lsattr -El <ent device> | grep large' and see if large send and large receive are enabled.
2) Issue 'traceroute <serverA>' to make sure it's only one hop to get to server A.
3) Issue 'no -L | grep -e tcp_send -e tcp_recv' to see what the send and receive socket buffer sizes are.
4) When you transfer the file, what method do you use? ftp? scp? something else?