Re: [ovirt-users] Strange network performance on VirtIIO VM NIC

Hello all. I have a peculiar problem here which perhaps others may have had or know about and can advise. I have Virtual Machine with 2 VirtIO NICs. This VM serves around 1Gbps of traffic with thousands of clients connecting to it. When I do a packet loss test to the IP pinned to NIC1 it varies from 3% to 10% of packet loss. When I run the same test on NIC2 the packet loss is consistently 0%. From what I gather I may have something to do with possible lack of Multi Queu VirtIO where NIC1 is managed by a single CPU which might be hitting 100% and causing this packet loss. Looking at this reference (https://fedoraproject.org/ wiki/Features/MQ_virtio_net) I see one way to test it is start the VM with 4 queues (for example), but checking on the qemu-kvm process I don't see option present. Any way I can force it from the Engine ?

This other reference (https://www.linux-kvm.org/page/Multiqueue#Enable_MQ_ feature) points to the same direction about starting the VM with queues=N Also trying to increase the TX ring buffer within the guest with ethtool -g eth0 is not possible. Oh, by the way, the Load on the VM is significantly high despite the CPU usage isn't above 50% - 60% in average.

Thanks Fernando _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users