Hi!

I run Hyper-V on a physical Win Server 2012 R2. I have a single Server 2012 R2 Guest VM but multiple physical network cards. Now I would like to allow my single VM to make use of those multiple NICs in order to increase bandwidth.

To achieve this, is it ok to create a NIC team in the Hyper-V host or do I need to create the team inside the guest VM (instead of in the host) to make use of multiple physical NICs from inside this VM?

Thanks in advance.

Anguel

Hello,

If you need bandwith, create a Team on Hyper-V host. Add your physical network cards.

Where ? -> Local Server - NIC Teaming - Tasks - New Team - LACP mode. Select physical network cards.

Select LACP mode to create a "tunnel" with your network cards. If you have two 10 Gbps cards, you will have 20 Gbps. But your must configure LACP on your switch.

When it's done, create Virtual Switch Manager in Hyper-V Manager. Select the new team.

In VM, select the new virtual switch.

It's done :)

Remi

Teaming host NICs together creates a larger pipe for the External Virtual Switch.

However, if you only have one VM it really does not give a bigger pipe to a single VM.  Since the VM traffic ends up taking a common path.  Teaming the physical NICs is about redundancy, not increasing bandwidth.

If you application in your VM can handle it - the way to give a single VM more bandwidth is to:

1) move from 1Gb to 10GB to 40GB physical NICs

2) create a virtual switch on each physical NIC.  And attach the VM to all of the external virtual switches.  Team the vNICs within the OS of the VM.

It is all about where is you most limiting point (where is the straw the smallest).

Personally, I would first prove that bandwidth is an issue before I try to fix it. In the vast majority of cases bandwidth to / from a VM is not the issue (not at the hypervisor) - some other factor is.

And, rarely does the OS even saturate a 1GB NIC. If your NIC is truly saturated, the OS in the VM is truly filling the NIC, then focus on it.

Brian,

Thank you for your reply. I first thought that it would be possible to get 2 Client PCs copy large files from the server at approximately 2 x 100 MB/s (total) when I team 2 NICs and if one 1Gbps NIC can deliver 100 MB/s...

If I understood you correctly, this is not possible at all if the files are copied from within a single VM on the server and if host-level teaming is used. Is this correct?

Anguel

The 2 vNICs will share in the full 1Gb of the physical NIC until that physical NIC is saturated. 

You don't get 100Mb per physical NIC.

Use 1 physical NIC and test copying from both VMs at the same time.  Also, be sure that the Integration Components in the VM are at the level equal to the Hyper-V server.

On the LBFO feature - your load balancing algorithm defines if you have load distribution, pinning, etc.  VMs (by default) pin, since it is generally more efficient (all hypervisors default to this way).

Brian,

Thank you for your reply but I am still confused. You are talking about testing with 2 VMs. However, as mentioned above in my setup I only have a single VM and I have 4 physical NICs (1 Gbps each) in the host.

My simple question is: Is it possible to make this single VM use the bandwidth of more than one physical NIC at a time (i.e. > 1 Gbps) when copying large files to multiple physical workstations and is this achievable by teaming the physical NICs at the host level?

If I team the 4 NICs in the host I end up with a NIC team that uses the Microsoft Network Adapter Multiplexor Driver, then I create an external Hyper-V switch and connect it to this Microsoft Network Adapter Multiplexor Driver and finally inside my VM I get a Microsoft Hyper-V Network Adapter connection rated at 10 Gbps. So I still expect to get a speed increase through the NIC team...

Anguel