Can you check the offload settings of the tap device that is connected to guest?
Run “ethtool -k tap-solaripub”.
On the guest. Raise the log verbosity by going to device manager -> NetKVM device -> Advanced tab -> Logging.Level and changing it to 4. Use DebugView to record the driver tracing (enable kernel trace): http://technet.microsoft.com/en-us/sysinternals/bb896647.aspx
Best regards,
Yan.
On Nov 22, 2013, at 7:28 PM, Mario De Chenno <address@hidden> wrote:
Hi all.We are facing some network issues on some Windows Server 2003 machines.In short, network seems to lock up and stops responding even to ping requests. From TCPdump on the tap interface on the server I only see arp request to the gateway, without replies. Increased tx overruns on the some interface too. No errors at all on windows side. Most of the time we can disable the interface from within windows and re-enable it to make things work again. Rarely we have to shut down the virtual machine (Windows reboot does not solve the problem).The issue appears randomly without apparent relation with server activity. One server makes a lot of small outbond connections and locks up about every 12-24 hours. It has two nic defined and only one is affected (the heaviest loaded). Other servers have just one nic and lock less often.We run Qemu-kvm 1.4.0 and latest virtio-win drivers. On the same host we did run a Linux web server with no issue in months of activity, with traffic peaks up to 80Mb/s.Here's is the startup command:qemu-system-x86_64 -enable-kvm -machine type=pc,accel=kvm -cpu kvm64 -pidfile /vmstore/vm_pids/solari.pid -rtc base=localtime -drive file=/vmstore/vm_disks/solari.img,if=virtio -netdev tap,id=nic01,ifname=tap-solaripub,script=pub102-ifup -device virtio-net-pci,netdev=nic01,mac=CE:DA:01:00:17:16 -netdev tap,id=nic02,ifname=tap-solariconsip,script=consip-ifup -device virtio-net-pci,netdev=nic02,mac=CE:DA:01:00:16:16 -vnc :16 -m 4096 -boot c -k it -usbdevice tablet -name solari -daemonize
We tried also the following options without result,vhost=off,vnet_hdr=on,ioeventfd=on,event_idx=offHow can we troubleshoot the issue?Thanks