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Network connection of KVM is unstable on SLES11/openSUSE11.1

3 replies [Last post]
miles
Offline
Joined: Apr 22 2009
Points: 0

Hi all,

I tried to build the VM with qemu-kvm on SLES11/opensuse11.1 on x86-64.
The network device was TAP with bridge.

==============
linux-gwsa:/srv/ovs/images # uname -a
Linux linux-gwsa 2.6.27.19-5-default #1 SMP 2009-02-28 04:40:21 +0100 x86_64 x86_64 x86_64 GNU/Linux
linux-gwsa:/srv/ovs/images # rpm -qa | grep kvm
kvm-78-13.8
kvm-kmp-default-78_2.6.27.19_5-13.8
linux-gwsa:/srv/ovs/images # lsmod | grep kvm
kvm_intel 49104 1
kvm 172488 1 kvm_intel

linux-gwsa:/srv/ovs/images # brctl show
bridge name bridge id STP enabled interfaces
br0 8000.001a644887b6 no eth0
linux-gwsa:/srv/ovs/images # ifconfig br0
br0 Link encap:Ethernet HWaddr 00:1A:64:48:87:B6
inet addr:192.168.0.13 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::21a:64ff:fe48:87b6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:359030 errors:0 dropped:0 overruns:0 frame:0
TX packets:4386 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:74380332 (70.9 Mb) TX bytes:4912255 (4.6 Mb)
linux-gwsa:/srv/ovs/images # cat /etc/qemu-ifup
#!/bin/sh

echo 'config qemu network with bridge for ' $*

bridge=br0
# Exit if $bridge is not a bridge. Exit with 0 status
# so qemu-dm process is not terminated. No networking in
# vm is bad but not catastrophic. The vm could still run
# cpu and disk IO workloads.
# Include an useful error message in qemu-dm log file.
if [ ! -e "/sys/class/net/${bridge}/bridge" ]
then
echo "WARNING! ${bridge} is not a bridge. qemu-ifup exiting. VM may not have a functioning networking stack."
exit 0
fi

ifconfig $1 0.0.0.0 up
brctl addif $bridge $1 || true

===================
I booted the KVM with
# qemu-kvm -m 8192 -smp 4 -hda /dev/sdb1 -net nic -net tap

In the VM, the network worked well by "ping". When I copied a huge file (2G) from other machine, the max speed was 300kB/s and disconnected after server seconds.

However, after made the eth0 down and up, the connection was ok again. It would failed when copying big file again.

Did it the KVM on SLES problem? Did anyone hit it also?

miles
Offline
Joined: Apr 22 2009
Points: 0
network device

I check the network device on 1000MB/s connection:

use rtl8029 (default device) on SLES10SP2, max 300kB/s , unstable
use e1000 in SLES10SP2, max 5.6mB/s, stable
use virtio on SLES11, max 11kB/s, stable

Anonymous
bridge for a SIUSE VM at the host machine

I need an explict advice how to configure a bridge for a SUSE host to serve as bridge for Virtual machines under
this host . Later on I will start the VM using the following
command : qemu-system-x86_64 -hda -smp 8 -m 2048 -net nic -net tap

The problem: From SUSE man pages it is not clear if I should set a separate ifcfg-br0 file with the basic bridge info or add this basic bridge info to the existing (non bridge) ifcfg-eth-id- file for eth0 . I tried both , then restarted the network on the host and the system stuck in these cases . So I am missing something .

Can anyone help

Anonymous (not verified)
bridge for SUSE

Hi ,

for me verio was stable on SLSES11 guests if im using one interface, but i have a requirement to use 3 nics on 2 SLES11 guests , virtio was not stable got many duplicate packets, and the connection disconnects..

i tried e1000 for all the nics on both guests worked(stable) fine for me .

bandwidth test output

[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 1.0 sec 29.0 MBytes 243 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 1.0- 2.0 sec 42.0 MBytes 353 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 2.0- 3.0 sec 40.5 MBytes 340 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 3.0- 4.0 sec 36.0 MBytes 302 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 4.0- 5.0 sec 48.6 MBytes 407 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 5.0- 6.0 sec 41.2 MBytes 346 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 6.0- 7.0 sec 41.3 MBytes 346 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 7.0- 8.0 sec 39.7 MBytes 333 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 8.0- 9.0 sec 42.1 MBytes 353 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 9.0-10.0 sec 38.0 MBytes 319 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 398 MBytes 334 Mbits/sec

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