multiple vmnics for vMotion

[daunce]

In all the network designs i've found, the common theme seems to have a vSwitch with 2 pNICs, and separate port groups for service console and vMotion, both having active/standby alternate vmnics. ie: Kendrick Coleman's vSphere NIC Design

Curious on if it is worth having more than 1 active vmnic for vMotion?

After watching esxtop network stats, during a host being put in maintenance mode, the 1 vmnic assigned to vMotion hits 900Mb/sec.  (1Gb port)

By making it active/active, would it max out both vmnics during a vMotion, and speed up the process of moving VM's?

We have pNICs to burn..

[a_p_ · Accepted solution]

By making it active/active, would it max out both vmnics during a vMotion, and speed up the process of moving VM's?

No, the VMotion/VMKernel port group - like any virtual machine - will be assigned to one of the active NICs at startup. The second NIC would only be used in case of a failure of the first NIC.

André

[Gerrit_Lehr]

I have not found a clear answer to this but fom my understanding (which fairly might not be the best when it comes to networking) you won't get more bandwidth since all traffic comes from VMKernel and there is nothing to load across the second channel.

[naveenvm]

I guess you would have to port channel both ports from the physical switch side, only then the load will shift across both nodes.

Regards

[daunce]

Thanks guys.

André, i've been going through the esx config guide, but unable to find more about that. any pointers to it in the doco?  Is it from the normal load balancing policy, and as the source is the vmkernel, it's always going to have the same portID/IP/MAC?

[bulletprooffool]

The scenario you are hoping for is port channeling rather than load balance.

Load balance will simply shift alternating sets of traffic through alternating nics depending on policy.

To get use out of both pNic you could separate different types of traffic across different pNics in a vSwitch (i.e. you could create 2 PortGroups and get 1 Portgroup to default to pNic 1 and the other to pNic 2)

[malaysiavm]

If you had configure with port channel for link aggregation, the bandwidth consumption on the physical link should be equally split, of course the teaming policy require to be changed as well