Load balancing algorithms always "static mapping from vSwitch port to pNIC adapter"?

[thattommyhall2]

I'm looking a LBT for my move to 10G ethernet and saw this KB

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=102259...

It says

"""

In vSphere 4.0, there are three policies:

• Route based on the originating virtual Port ID
• Route based on IP hash
• Route based on source MAC hash

These three policies provide static mapping from vSwitch port to pNIC adapter.

"""

I always thought IP hash would allow one VM to use more than one pNIC if it sent to multiple IPs, am I wrong or the KB?

Tom

[a_p_]

I always thought IP hash would allow one VM to use more than one pNIC if it sent to multiple IPs, am I wrong or the KB?

You - as well as the KB - are correct, it will use multiple pNICs to multiple targets, however it's always one pNIC which is used for each VM-->target mapping.

see http://kensvirtualreality.wordpress.com/2009/04/05/the-great-vswitch-debate%E2%80%93part-3/

André

[thattommyhall2]

These three policies provide static mapping from vSwitch port to pNIC adapter.

IP hash does not according to the article you link to, one vSwitch port will have traffic leave via dirrerent pNICs, I think the KB is wrong (or at least phrased awkwardly)

[a_p_ · Accepted solution]

Maybe it's not described as clearly as it could be. However, traffic from one VM (IP address) to a specific target (IP address) will always be sent over the same pNIC. That is what the article describes as static.

Since you are looking for load balancing. Did you already take a look at vSphere 4.1. It offers "Load-based Teaming". Maybe you want to read http://blogs.vmware.com/performance/2010/12/vmware-load-based-teaming-lbt-performance-.html for details and performance.

André

[thattommyhall2]

I am looking at going for LBT  indeed (that is the KB for it), it just made me worry I had  misunderstood IP Hash in the past. I still think "from vSwitch port to  pNIC adapter" is wrong but can live with it 😉

Read the article today too and it is superb.

Tom

[RBurns-WIS]

Just to add when you're using an upstream "Etherchannel" aka Port Channel you would set the Balacing to "IP Hash".  This will allow the traffic to use both NICs as a single logical interface.

Regards,

Robert