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Slow download/Upload speeds in VM

asked 2014-06-24 09:22:27 -0500

granadol gravatar image

I am stumped. I have turned off gro and tso on virtio network adapter in VM. I get on average 10 mbs down and 3 mbps upload. Outside of VM, my upload and download speeds are 49mbps respectively. Intra-vlan traffic is good averaging at 66mbps when performing iperf testing. Internet access to instances are slow. Any ideas or is this normal behavior. I have a dedicated compute, network, controller node. I am using GRE. The host nic's are 1000.

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answered 2014-06-25 13:00:02 -0500

mpetason gravatar image

Gro/TSO should be turned off on the physical NIC on the network node attaching to the public network. You could also turn it off for other interfaces since you aren't really using it. You wouldn't need to do this within the VM.

Documentation Reference(Section 5):

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GRO/TSO are turned off on physical NIC connected to br-ex on network node. Speedtest within the router namspace shows much better bandwidth than instances. No issues are seen using tcpdump/wireshark. Performance is worse when using the e1000 NIC rather than the virtio one.

granadol gravatar imagegranadol ( 2014-06-25 13:40:36 -0500 )edit

That sheds a little more light on it. Is there a specific reason you need to use e1000 instead of virtio? Are the instances based off of VMDK images? It should be possible to modify the vmdk configs to use virtio instead.

mpetason gravatar imagempetason ( 2014-06-25 13:50:35 -0500 )edit

I tried the e1000 to see if it would help the bandwidth issues, defaults is virtio. Speedtest is much faster when running within the qrouter namespace. I cannot get those same results in instances. Tried other images like centos, This instance is ubuntu cloud x64. Anyhelp would be much appreciated.

granadol gravatar imagegranadol ( 2014-06-25 14:02:48 -0500 )edit

Which Kernel are you running currently? Do you see any errors/issues in the ovs agent logs? Are there any dmesg errors or errors in the /openvswitch log directory?

mpetason gravatar imagempetason ( 2014-06-25 15:09:04 -0500 )edit

No errors in ovs_agent logs or openvswitch logs. Current kernel 3.13.0-29-generic

granadol gravatar imagegranadol ( 2014-06-25 15:22:10 -0500 )edit

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Asked: 2014-06-24 09:22:27 -0500

Seen: 1,596 times

Last updated: Jun 25 '14