Open Stack

Greetings,

My openstack grizzly cluster runs on ubuntu 12.04 servers with 10G NICs.
I have ubuntu, centos and windows 2008 R2 guests.  I've noticed that
while both my linux guests can communicate at some reasonable
approximation of 10G wire speed (e.g., 7-9Gb/sec on iperf tests), the
windows guests max out at 2.5G when talking to the host on which they
run, down to ~1.2G to other hosts.

I've made some modifications as per this doc:

http://www.linux-kvm.org/page/WindowsGuestDrivers/kvmnet/registry

and upgraded my virtio network driver, but it's not helped.  I've also
done about an hour or two of googling which has revealed little.

I understand that this is not an openstack issue, but, I suspect, others
have encountered this when bringing 2008 R2 guests into their clusters.
Anyone?

Thanks much,
JR