AIX

Hi,

Recently I've been doing some performance changes for inter-lpar configs and completing some testing. So far test have been successful and promising but only completed in a dev environment.

Here is what I've done
created a separated vlan for inter-lpar communications separate from the VIO.
adjusted the MTU to 65280, and enabled Large Send.

transferred have increased by aprox 70% in some test. lowest was a 50% increase from the original configurations on other servers. I did see a improvement in terms of CPU as well compared to using default settings.

so my main question is this....
overall it was great. the problem which i was expecting was sftp/scp.
using nmon i did confirm they were transferring on the correct ports but transfer times were extremely slow.

I was using a 6GB file for test, on ftp best avg time was 14 seconds (all test were completed by a average of 10 test) when transferring 6 6GB files at the same time, avg time was 23 seconds.

Using sftp/scp transfer times were 2:30 min. 6 files approx 5 min.

so my next step was to try changing the algorithm on these processes which i personally was trying to avoid. I didn't run 6 concerent test with this one but the avg time was around 1:30 min.

Here was what i used for sftp:

Code:

sftp -B 260000 -o Ciphers=arcfour -R 512

here is what i used for scp:

Code:

scp -c arcfour

from ifconfig on this interface:

Code:

tcp_sendspace 262144 tcp_recvspace 262144

when using MTU=65280 and largesend what would be the best thing to adjust in terms of network tuning.

As I said this is just dev testing and I know real cases will be different but I'm just trying to see what improvements I can make since some people have been complaining about slow transfers between systems and this was the best i can think of at the moment.

Hi,

I found and used a nice guide for our network setup.

In our environment a inter-lpar scp -c arcfour copies a file with nearly 80MB/s.

Regards