kvm nfs hang

I ran into a strange NFS + KVM issue. Every so often under heavy NFS load my KVM client would hang retrying the nfs server. On the console the client was showing:

    nfs: server host not responding, still trying

I found this bug post which does not seem to have been resolved in 2.6.24.

Using the kvm flag -net nic,model=rtl8139 fixed the problem for me.