Re: [libvirt-users] performance with libvirt and kvm
On Tue, Aug 3, 2010 at 11:04 PM, Nirmal Guhan <vavatutu(a)gmail.com> wrote:
I am seeing a performance degradation while using libvirt to start
my
vm (kvm). vm is fedora 12 and host is also fedora 12, both with
2.6.32.10-90.fc12.i686. Here are the statistics from iperf :
From VM: [ 3] 0.0-30.0 sec 199 MBytes 55.7 Mbits/sec
[...]
qemu kvm : [ 3] 0.0-30.0 sec 329 MBytes 91.9 Mbits/sec
Is this what you are comparing: 91.9 -> 55.7 Mbits/s?
Command used : qemu-kvm vdisk.img -m 512 -net nic,model=virtio
macaddr=$macaddress -net tap,script=/etc/qemu-ifup
Have you tried to bisect the command-lines by dropping options from
the libvirt command-line until you arrive at the manual qemu-kvm
command-line?
Try using your own tap networking instead of libvirt's but otherwise
keeping libvirt's command-line as much as possible.
Can you use /var/lib/libvirt/f12.img with the manual qemu-kvm instead
of the vdisk.img file? In general, try to compare same with same and
eliminate variables.
Stefan