Gentlemen, Reaching out with a non-development question, sorry if it's not appropriate here. I'm looking for a way to improve Linux SMP VMs performance under KVM. My preliminary results show that single vCPU Linux VMs perform up to 10 times better than 4vCPU Linux VMs (consolidated performance of 8 VMs on 8 core pre-Nehalem server). I suspect that I'm missing something major and look for any means that can help improve SMP VMs performance. VMs are started using: qemu-kvm -m $ram -smp $cpus -name $name -drive file=${newimg},boot=on,cache=writethrough -net nic,macaddr=$mac,vlan=0,model=virtio -net tap,script=/kvm/qemu-ifup,vlan=0,ifname=kvmnet$i -parallel none -usb -k en-us -monitor pty -serial pty -nographic -daemonize -snapshot KVM Host Environment (redhat 5 based): # uname -r 2.6.18-194.el5 # rpm -qa|grep kvm kvm-83-164.el5 kvm-tools-83-164.el5 kmod-kvm-83-164.el5 kvm-qemu-img-83-164.el5 Thank you, Alec -- 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