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