Hi Craig and Ron,

I am the customer that Rob's case study was based on. I had the exact same 
problem (with 1 GbE OSA's) that you are having. Your problem is indeed the 
VSWITCH. Kick it and use native bonding in Linux. If you need more than one 
guest, buy more OSA's, they are way cheaper than IFL's ;-))

Best regards,
Pieter Harder

________________________________________
Van: Linux on 390 Port [linux-...@vm.marist.edu] namens Ron Foster at Baldor-IS 
[rfos...@baldor.com]
Verzonden: maandag 26 oktober 2009 20:11
Aan: LINUX-390@VM.MARIST.EDU
Onderwerp: Re: OSA-Express3 10 Gb, Vswitch, and SLES10 Linux Throughput

Craig,

In another SHARE session, I seem to remember that if you need to have
very communications high throughput
then you do not want to use VSWITCHes.  Instead you want to dedicate a
connection to the OSA adapter.

(I am unable at the moment to find that presentation.)

However, in Mario Held's presentation, where he is going
through the performance characteristics of the various types of
communications, there is a phrase that says
"Use direct OSA for outside connection of demanding guests"

Also in Rob van der Heij's presentation "Linux on z/VM Understanding CPU
Usage," there is a section
"Improving TSM Throughput."  This presentation presents a case study.
You might find it interesting.

Ron

Craig Collins wrote:
> We are just starting to use OSA-Express3 10 Gb ports for SLES10-SP2 Linux
> guests.  We're trying to use these with TSM servers running on SLES10 to
> backup other non-zSeries servers in our environment.  We are using the 10 Gb
> OSAs connected to VSWITCHes in zVM 5.4.  Currently we have only one SLES10
> TSM server connected to a VSWITCH that is the only thing connected to a 10
> Gb OSA and are seeing throughput of less than 1 Gb/s.  The Cisco switch the
> OSA port is connected to recognizes the speed as 10 Gb.  The TSM server and
> all of the servers it is backing up are on the same subnet and there is no
> firewall involved.
>
> Thanks to linuxvm.org, we found Share presentation 2192 by Mario Held from
> August 2009 named "Linux on System z Performance Update - Part 2: Networking
> and Crypto" which we found helpful and we have altered some of our settings
> based upon the recommendations.  We also have been over the OSA and Vswitch
> documentation from IBM looking for any speed settings related to this type
> of OSA card, a VSWITCH, or a nic definition for a linux guest on zVM, but
> did not find anything.
>
> We still are not getting throughput we expect (or maybe desire).  We
> wondered if a nic setting in SLES10 could be keeping the connection from
> getting above the 1 Gb/s mark, but cannot find a parameter to change as the
> normal parameters with ethtool don't seem to apply in this environment.
>
> Is anyone else using a 10 Gb OSA through a VSWITCH and getting throughput
> greater than 1 Gb for a single server instance?  If so, are there any
> settings you needed to change to get to that performance level?  Or is there
> a maximum of around 1 Gb that a single server instance can achieve?  We're
> grasping at straws at this point.  Any ideas are appreciated.
>
> Craig Collins
> State of WI, DOA, DET
>
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