Very low bandwidth on VXLAN VNET <10mbit

Community Support Network
1

Hello
I’m trying to use VXLAN network for my guests.
But perfomance is very low.
This is iperf3 test between two VM’s in one VNET within one host:

[ 4] 9.00-10.00 sec 225 KBytes 1.85 Mbits/sec 45 5.46 KBytes
[ 6] 9.00-10.00 sec 233 KBytes 1.91 Mbits/sec 36 6.83 KBytes
[ 8] 9.00-10.00 sec 225 KBytes 1.85 Mbits/sec 44 6.83 KBytes
[ 10] 9.00-10.00 sec 243 KBytes 1.99 Mbits/sec 54 6.83 KBytes
[ 12] 9.00-10.00 sec 231 KBytes 1.89 Mbits/sec 48 6.83 KBytes
[ 14] 9.00-10.00 sec 262 KBytes 2.15 Mbits/sec 44 6.83 KBytes
[SUM] 9.00-10.00 sec 1.39 MBytes 11.6 Mbits/sec 271

When I’m using 802.1 VNET i’m getting about 1.6Gbit on same hardware, that is not very much on 10G net.

I’m using Centos 7 as hosts and Ubuntu from app as VM
What can cause such low speed?
Thanks

2

Any suggestions?
Does anyone have success with vxlan on centos nodes?

3

I’m using vxlans no issues which nic are you emulating in the guest VM is it a virtio nic

4

What OS are you using for hosts?
I’m using centos with 3.10 kernel

5

Yes, I changed default template from App store to use virtio NIC model
and it fixed everything, thanks
root@ubuntu:~# iperf3 -c 10.229.0.23
Connecting to host 10.229.0.23, port 5201
[ 4] local 10.229.0.22 port 54564 connected to 10.229.0.23 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 197 MBytes 1.65 Gbits/sec 1336 274 KBytes
[ 4] 1.00-2.00 sec 230 MBytes 1.93 Gbits/sec 298 593 KBytes
[ 4] 2.00-3.00 sec 279 MBytes 2.34 Gbits/sec 0 864 KBytes
[ 4] 3.00-4.00 sec 280 MBytes 2.35 Gbits/sec 3 872 KBytes
[ 4] 4.00-5.00 sec 309 MBytes 2.59 Gbits/sec 35 1.07 MBytes
[ 4] 5.00-6.00 sec 321 MBytes 2.69 Gbits/sec 162 916 KBytes
[ 4] 6.00-7.00 sec 320 MBytes 2.68 Gbits/sec 271 857 KBytes
[ 4] 7.00-8.00 sec 316 MBytes 2.65 Gbits/sec 0 1.07 MBytes
[ 4] 8.00-9.00 sec 305 MBytes 2.56 Gbits/sec 232 896 KBytes
[ 4] 9.00-10.00 sec 292 MBytes 2.45 Gbits/sec 0 1.08 MBytes

[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 2.78 GBytes 2.39 Gbits/sec 2337 sender
[ 4] 0.00-10.00 sec 2.78 GBytes 2.39 Gbits/sec receiver

1 Like
6

Great stuff !! I usually just change it in the templates as it’s easy to forget , the default nic it emulates is a 10mb nic which I don’t think anybody these days wants :joy: glad it’s sorted