Etherchannel - Performanceproblems

[TSch]

Hi folks,

we're using Etherchannel in one of our AIX Systems
(V5.2 ML 2).

If we're sending data into one direction (Machine A to Machine B) it's working fine (80 mbyte/sec) whenever we send data into the other direction (Machine B to machine A) we only have 40 mbyte/sec.

Any ideas ?

Thanks in advance !

Regards,
Thomas

 

[MoshiachNow]

Normally these issues are higly dependant on the source/destination disks throughputs.

I would advise to write localy a 1 GB file on the destination machine using topas - so that you will know what is the max write speed of the target disk.
Then if the speed is much higher then 40MB/sec - you can start dealing with network performance.
If not - the disk write speed is your bottleneck.

"Long live king Moshiach !"

http://www.7for70.com/

 

[TSch]

Hi,

sorry I forgot to mention one important detail

physically it's the same machines. Residing as LPARS on the same p670. Connected to the same ESS ... So actually there shouldn't be any differences in the hardware ...

Regards,
Thomas

 

[MoshiachNow]

If it's the same physical disk used for both read and write - you may have to check your network interfaces and switch settings.

"Long live king Moshiach !"

http://www.7for70.com/

 

[TSch]

Ok,

but if we're using the same network interfaces as well as the same switch, how can it be that direction A -> B is ok and direction B -> A is not ?

It's the same adapters just another direction ...

Regards,
Thomas

 

[sbix]

Did you try to play with the load balancing options? Expecially with the HASH MODE one?

 

[bonsky]

We maybe looking at various reasons if its not configured as an exact replica of the other machine. One reason maybe is ethernet configuration and may not be the same way? Or rather are both servers connected to the same switch if not are they configured similarly(switch ports). Or perhaps, Is the other server running an application which uses a lot of network resources. So, they are correct for you to ise such performance tools, like topas, and figure it out before and after the transfer load.
Good luck dudes!