10gbps

T

TB12

New Member
Aug 2, 2011
10
0
1
Do any of the KVM virtual NIC's support 10gbps within the VM?

I've got a 10gbit network connection that I'd like to use, but I can't seem to get anything above 1gbps.
Is this not supported?
 
how do you test? I suggest you run iperf from guest to host.
 
Well, the highest I can get my Windows Server 2008R2 KVM guest to connect at is 1gbps using the virtio driver. It looks like the driver will only sync at 10mb, 100mb, and 1gb without the option for 10gb.

Am I missing something? If you could point me in the right direction I would be very grateful.
 
Well, I hadn't run any iperf tests because the Windows system is only able to connect at 1gbit for some reason.
For example, this is the host connection:

Settings for eth0:
Supported ports: [ FIBRE ]
Supported link modes: 10000baseT/Full
Supports auto-negotiation: No
Advertised link modes: 10000baseT/Full
Advertised auto-negotiation: No
Speed: 10000Mb/s
Duplex: Full
Port: FIBRE
PHYAD: 0
Transceiver: external
Auto-negotiation: off
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
Link detected: yes



And this is what Windows is connecting at using the virtio driver:

20110804-dpi2jab5q36pjs8egb1j37a152.jpg

Running an iperf test from the guest to the host gives the full 1gbit speeds, however I'd like to use the full 10gbit speeds that the host is connected at.

[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 966 MBytes 810 Mbits/sec

How do I get the guest to sync at 10gbit rather than 1gbit?
 
Can we login again directly to your box, and do some testing with a fresh installed win2008r2? we have no 10gbit network here so I would like to run some tests.
 
There should be a new ticket created with the login information.
I appreciate you looking into this Tom.
 
TB12 said:
Do any of the KVM virtual NIC's support 10gbps within the VM?

I've got a 10gbit network connection that I'd like to use, but I can't seem to get anything above 1gbps.
Is this not supported?
Click to expand...
Hi,
yes you can reach more (but not so much).

I have done one short test with grml and virtio-driver:

VM -> host-a (10GB) -> host-b

Here come the output from host-b:
Code: 
iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local 172.20.0.11 port 5001 connected with 172.20.0.20 port 58917
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  1.33 GBytes  1.14 Gbits/sec

iperf -c 172.20.0.20
------------------------------------------------------------
Client connecting to 172.20.0.20, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 172.20.0.11 port 44157 connected with 172.20.0.20 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  2.17 GBytes  1.86 Gbits/sec

Iperf from host-a to host-b shows 5.62 Gbits/sec and reverse direction 8.27 Gbits/sec (the different is driver/802.1q depends i guess).

I guess the bottleneck with the kvm-vm is the cpu-power.

Udo
 
Are you able to get those speeds in Windows though? Linux seems to work fine with 10gbit, but Windows only wants to sync at 1gbit speeds.
 
You must log in or register to reply here.
Top Bottom