Qemu-kvm, virtual network stalling under load


Hi, i have this problem with every network model and also using the newest release 0.12.3, which states that this problem is fixed for virtio-net :-/

host system is slackware64 13.0, guest too! kernel on qemu-kvm-0.12.3
network is bridged using tap and virtio (copy performance around 60MB/s until stall :frowning:

copying large files via scp from the host to vm’s /dev/null works! but copying e.g. the slackware-installiso from a mounted nfs share stalls the network of the virtual machine completely!!
also transfering a few hundret megs via ftp/ftps stalls the network completely!
no network response from the vm (ssh, icmp, etc…)
i can only shutdown and restart the vm using qemu monitor since i am running headless servers!

when using another NIC model the amount of transferable data decreases to only a few megs untill the network stalls :-/

error logs simply say nothing that indcate the problem :-/

anyone some hints or a possible solution for this defect?



Before I get in to too much detail, I want to make sure you are around and are still having issues. Let me know and i should be able to help you figure this out, our set-ups sound pretty similar. The main question I need to know the answer for is if you are running the virtual machine/server to update your business continuity, or if there is another reason besides the mission you are embarking upon. Please get back to me and we can get started in solving your problem.