One more important thing is to make sure you launch vhost thread for your virtio nic, as part of Guest instantiation. There will be a parameter "vhost=on" in Guest instantiation command line. -----Original Message----- From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On Behalf Of Venkateswara Rao Nandigam Sent: Thursday, May 15, 2014 10:20 AM To: JR; kvm@xxxxxxxxxxxxxxx Subject: RE: Poor performance with virtio network driver on windows 2008 R2 on KVM Try TSO offload on Guest Virtio interface And try passthrough interface mode at Host Level for this Guest Virtio Interface Thanks, Venkatesh -----Original Message----- From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On Behalf Of JR Sent: Wednesday, May 14, 2014 9:07 PM To: kvm@xxxxxxxxxxxxxxx Subject: Poor performance with virtio network driver on windows 2008 R2 on KVM Greetings all, Though I don't believe that this is KVM problem per se, I'm seeing very poor network performance when using windows 2008R2 KVM instances with the virtio driver when on a 10G network. iperf results show linux VMs getting close to wire speeds, while windows only does about 1.3Gb/sec. I've tried a number of tcp settings (chimney, etc...) as recommended by some google searches but nothing has helped. Does anyone have any advice? Thanks much, JR -- Your electronic communications are being monitored; strong encryption is an answer. My public key <http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4F08C504BD634953> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
