Salutations to all members, first off. This is my first post in the discussion group.
I would like to ask if anyone else had troubles with the network performance in the guest network. I am running qemu using ubuntu-14.04 as host. The guest is also ubuntu-14.04. In the guest OS, I have a LAMP stack properly configured. Users can reach the apache server inside via a host NATed tap interface. Anything poking the host at port 80 is passed into the private network between the guest/host. This all works well, and seems to be OK. Users can view websites and download files hosted in the guest LAMP.
Except, users are getting very limited download speeds. While the host sits on a 100Mbps symmetric up/down link, users are only able to download at 15Kbps or max 30Kbps. I used to have the same setup running natively without QEMU and user download speeds were great. Once I moved the LAMP stack into the virtual machine, this issue came up. The following is the command line used to start up the qemu vm.
qemu-system-x86_64 -hda disk1.qcow -m 1G -smp 4 -enable-kvm -netdev tap,id=tap0,ifname=tap0,script=tap-config.sh -device e1000,netdev=tap0
Call me naive here, but is this kind of network performance expected? The guest OS is unusable.