vMotion network design considerations - Multi-NIC vMotion and Link Aggregation in vSphere 5.5 - Part2

In my previous Post, I tried to find out how support for LACP in vSphere 5.5 has changed the design consideration for vMotion Network.  One has to decide between Multi-NIC vMotion and Link Aggregation.

After some search on Internet and talking to my friends in virtualization domain, I was referred to this excellent post from Chris Wahl (VCDX -104) on his blog wahlnetwork.com
Not only does this post talk about this in depth but also the comments posted helped me understand the concept and its pros and cons even better.

Multi-NIC vMotion when used with LBT or Load Based Teaming is still a clear winner when compared to Link Aggregation for vMotion networks.

Few reasons for this are summarized here:

• A LAG can only perform traffic distribution. Even if NIC is saturated.
• LBT, on the other hand, actively examines traffic on a vSwitch. It is aware of the load on NIC which helps it avoid sending traffic on saturated NIC. 

Thoughts ?

So LBT is much better to load balance traffic in this case. 

That doesn't mean that LACP is bad and should not be used in vSphere designs. It perhaps has a different use case to suit its functionality. For eg: NFS based Storage.
I will post the pros and cons and use cases for when to use link aggregations in a different post.

Till then keep networking. Cheers !

vMotion network design considerations - Multi-NIC vMotion and Link Aggregation in vSphere 5.5 - Part1

vSphere 5.5 has been now out for some time. As always with a new release, there were some major enhancements (good for us), specially on the networking and vDS.

I was impressed by Multi-NIC vMotion support when it was introduced  in vSphere 5.0. With advent of 10G NIC cards and ever increasing size of worlkloads that run in single VM, it was important to leverage this technology to revamp existing vMotion.

And I must say, VMware is always two steps ahead in innovation and improving its product features.

I am today looking into the design consideration for vMotion network by using Multi-NIC vMotion and LACP support in vDS in vSphere 5.5 

LACP support till vSphere 5.1 was rather limited and exclusively dependent on IP Hash load balancing. With vSphere 5.5 a lot has changed with vDS specially LACP and support for all LACP load balancing types.

LACP now support dynamic link aggregation, multiple LAGs and is not exclusively dependent on IP Hash load balancing.

Till vSphere 5.1 Multi-NIC vMotion was correct as compared to LAGs backed NICs which in turn work on LACP. LACP support till vSphere 5.1 was rather limited and exclusively dependent on IP Hash load balancing.

Now for all of you who know how IP hash load balancing works and and how vMotion selects the preferred NIC can relate to this observation.

Rest of you can dig a little and it would be very clear. Please refer to excellent article by Frank Denneman ( Here )

I am still contemplating how does this change the LACP vs Multi-NIC vMotion debate. I am trying to discuss this with my friends in VMware and lets see what are there thoughts on this.

Keep watching this space on how has this changed with new vSphere 5.5