Thanks for the links. I followed the first one when I set these up
initially. I never got virt-install to work right. I create the
xml file and the disk image manually. I then just use virsh for
define, start and stop. My problem is the network performance is
the same as a 10MB network not 100MB or 1000MB like you would
expect. I switched from using br0 directly to trying to use the
tap0 interface. From my understanding, this allows it to get packet
data at ISO level 2 which should be faster and have less overhead.
I noticed exactly no performance difference either way though. That
is what bothers me. I am not sure what the bottleneck is. I had a
similar issue with VMWare in the past, it had the same speed
limitations but ONLY when communicating with the host, not when
communicating with other machines on the network. For example,
VMWare would be 10MB connections to the host but 100MB connections
to any other physical machine on the network.
On 04/12/2011 08:21 PM, Pablo Sánchez wrote:
Robert, following
http://www.howtoforge.com/virtualization-with-kvm-on-a-debian-squeeze-server
i reach to the conclusion that using kvm network config is
"troublesome".
I ended using "--network=bridge:br0 " on startup the vm, with qemu
.
Anyway, from another squeeze (my work computer), installed Virtual
machine manager and never
looked back. virsh never worked right for me .
Regards.
Pablo Sánchez
PS:
http://www.techotopia.com/index.php/Creating_Xen_and_KVM_RHEL_5_Virtual_Machines_from_the_Command-line_%28virt-install_and_virsh%29
was also helpful
I have tried a KVM setup 2 different ways. The first was using
a straight bridge without using tap at all. The WinXP VM is
using the latest known version of the virtio drivers. The
bridge is on a gigabit nic.
The second setup was using a bridge containing a tap0 interface
and using the tap0 interface in the KVM config.
I have tested network speeds from the host with other machines
in the network using iperf. Bridge interface to other machine
on the network is fast with with speeds you would expect from
using 1G nics. Using the same iperf tests, I get about 1/100 of
the speed when using the bridge or tap0 interfaces with the
virtio nic. WinXP shows the virtio nic as being 1 Gbps device.
I am including some of my config below. Anyone have suggestions
on how to get greater than 1MBs transfer rates when using KVM in
a bridged setup?
####interfaces####
iface br0 inet static
address 192.168.0.155
network 192.168.0.0
netmask 255.255.255.0
broadcast 192.168.0.255
# gateway 192.168.0.1
bridge_ports eth3 tap0
bridge_stp off
bridge_maxwait 0
bridge_fd 0
pre-up /usr/sbin/tunctl -u libvirt-qemu -t tap0
pre-up ifconfig tap0 up
post-down ifconfig tap0
####interfaces####
###libvirt xml file###
<domain type='kvm'>
<name>WINXPVM</name>
<uuid>f1340442-6088-11e0-a43a-001b214871e8</uuid>
<memory>524288</memory>
<currentMemory>524288</currentMemory>
<vcpu>1</vcpu>
<os>
<type arch='x86_64' machine='pc-0.12'>hvm</type>
<boot dev='cdrom'/>
</os>
<features>
<acpi/>
<apic/>
<pae/>
</features>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<emulator>/usr/bin/kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/kvm/WINXP/WINXP.img'/>
<target dev='hda' bus='ide'/>
<address type='drive' controller='0' bus='0'
unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<source file='/kvm/iso/WINXP-PRO-SP3-VIRTIO.iso'/>
<target dev='hdc' bus='ide'/>
<readonly/>
<address type='drive' controller='0' bus='1'
unit='0'/>
</disk>
<controller type='ide' index='0'>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x01' function='0x1'/>
</controller>
<interface type='ethernet'>
<mac address='de:ad:be:ef:9a:9e'/>
<target dev='tap0'/>
<model type='virtio'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03' function='0x0'/>
</interface>
<serial type='pty'>
<target port='0'/>
</serial>
<console type='pty'>
<target type='serial' port='0'/>
</console>
<input type='tablet' bus='usb'/>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='29005' autoport='no'
keymap='en-us'/>
<video>
<model type='cirrus' vram='9216' heads='1'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x02' function='0x0'/>
</video>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x05' function='0x0'/>
</memballoon>
</devices>
</domain>
###libvirt xml file###
--
Robert Goley
FOSS
Implementation Specialist
Toll Free: (800) 338-4984
Local: (770) 479-7933
Fax: (770) 479-4076
www.openrda.com
America's only Free & Open
Source fund accounting software company.
--
Robert Goley
FOSS
Implementation Specialist
Toll Free: (800) 338-4984
Local: (770) 479-7933
Fax: (770) 479-4076
www.openrda.com
America's only Free & Open Source
fund accounting software company.
|
