Hyper V Slow Network

[karldenton]

Hi all

 

I've setup a new server ML350 G8. Total of 32gb ram and 2 processors.

 

Setup hyper v on the host

 

It has 2 network cards in it so I've used 2 - one for the host nic and one for the hyper v nic.

 

In hyper v virtual switch manager i've got the box unticked that says "Allow management operating system to share this network adapter". I've also got it set on the correct nic.

 

The hyper v server I have setup finds the network fine (its now a member of the domain). However network access on it is very slow. It says it was going to take 5 hours to copy 1.5gb over from another network share. Pinging the current school physical server takes between 70ms and 100ms.

 

Also browsing a test share on the hyper v machine from the current physical server has a noticeable delay. (couple of seconds)

 

Have I got the setup correct please?

 

Thanks

Edited March 13, 2014 by karldenton

[win]

What OS is the host server? If you're using 2012 or r2 then you can join the 2 network cards together (in one team) and have the host and virtual machines share it.

[karldenton]

Yeah its 2012 R2 - does it need to be configured on the switch as well ?

[win]

No, just plug both cables from nic into the same switch. Then go to server properties and setup nic teaming. There will be just one network interface afterwards load balancing 2GB of network traffic. This one network interface can be used for the host and VMs.

[fiza]

I had this issue with Broadcom cards.

The problem was virtual machine queues.

 

Hyper-V Virtual Machine Very Slow Network - VMQ

[FN-GM]

What speed are the NICs on the host?

[sted]

I had this issue with Broadcom cards.

The problem was virtual machine queues.

 

Hyper-V Virtual Machine Very Slow Network - VMQ

 

yeah i had that on a couple of dell servers turned it off and it was sooo much better

[karldenton]

Perfect, that was the problem. Many thanks.

 

Would there be any benefit in leaving a host nic and teaming 2 or 3 others together for the vm's ?

[tmcd35]

If you want to run 2 NICs - 1 for VM's, 1 for Hosts, then make sure all the IPv4 and IPv6 settings are disabled on the VM NIC as they are not actually required and can cause DNS/Routing problems on the host (dual homed).

 

Essentially the VM NIC is being used as a switch uplink port to connect the virtual switch in Hyper-V to your physical switch. So think of it has connecting two switches together rather than connecting a PC to a switch.

 

As for teaming NIC's, it all depends on how many VM's your are hosting. The more hosted VM's the more they are sharing that switch uplink bandwidth, the more teamin will help by increasing available bandwidth. Think of it as the back bone connection between a couple of core switches.

 

If you are running Server 2012 and want to use NIC teaming then use the built in software teaming rather than any manufacturer specific driver based teaming. I've found Server 2012's built in teaming to be easier to configure and more reliable in the long run. Also, you may need to reconfigure the ports on your switch for teaming depending on which temaming method you opt for. Server 2012 can team NIC's without needing any switch configuration changes.

 

If you only have 2 NIC's then I really wouldn't bother with teaming, leave them seperate. If you need the extra bandwidth, and the host NIC is only being used for management then it might be an idea to buy a cheap USB NIC for the host and then team the two built in NICs for the VM switch trunk.

Edited March 13, 2014 by tmcd35