High Availabity for vMotion Across Two NIC’s

When designing your vCentre environment, good practice is to associate two physical network adapters (uplinks) to your vMotion network for redundancy.

The question is does VMware use both uplinks in aggregation to give you 2GBps throughput in an Active/Active configuration? the answer to this is no.

In the above configuration we have two uplinks both Active, using the load balancing policy ‘route based on originating virtual port ID’ this means that the VMkernel will use one of the two uplinks for vMotion traffic.  The secondary active adapter will be used but only if the uplink vmnic4 is no longer available.

You might say this is OK, I’m happy with this configuration, I say how can we make it more efficient?

At the moment you will have a single Port Group in your vSwitch which is providing vMotion functionality (in my case it’s also doing Fault Tolerance Logging)

And the vSWitch has two Active Adapters

What we are going to do is rename the Port Group vMotionFT to vMotionFT1, go into the Port Groups properties and change the NIC Teaming setting to the following:

So what have we changed and why? First of all we have over ridden the switch failover order, we have specified that vmnic4 is now unused and that we are not going to ‘failback’ in the event of uplink failure.

You may think hold on Craig, why have you done this now we have no HA for our uplinks, well the next step is going to be adding another Port Group as follows:

VMkernel Select
Network Label vMotionFT2
Use this port group for vMotion Select
Use this port group for Fault Tolerance logging Do Not Select
IP Address

Once completed, we are now going to edit the Port Group vMotionFT2, go back into NIC Teaming and over ride the switch failover order and set vmnic1 to unused and no for failback.

So what have we achieved?

1. vSwitch1 has two active uplinks
2. vMotionFT1 Port Group is active and uses vmnic1 for vMotion & Fault Tolerance Logging
3. vMotionFT2 Port Group is active and uses vmnic4 for vMotion
4. We can perform two vMotions simultaneously using 1GB of bandwidth each
5. If we have an uplink hardware issue vMotion continues to work

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