Hi Kashyap, Here I want to test and see how much I/O performance could be improved by virtio-blk data plane feature. Yes, this is a dirty way to enable it :-), You mentioned using newer libvirt, is there parameter similar "x-data-plane=on" in new version libvirt? Please let know me you if you have better solution. Regards, CY. On Mon, Apr 20, 2015 at 10:51 PM, Kashyap Chamarthy <kchamart@redhat.com> wrote:
On Mon, Apr 20, 2015 at 10:37:13PM +0800, Chengyuan Li wrote:
Hi,
I tried to enable virtio-blk data plane feature for VMs in my openstack environment, the hypervisor is ubuntu 14.04, libvirt 1.2.2
[I haven't tested the virtio-blk data plane myself.]
This libvirt version seems a little old (from March 2014), you might want to move to a bit newer.
and QEMU 2.0. As nova doesn't support that parameter yet, I did belows
1. nova boot a VM with raw disk image. 2. nova stop the VM. 3. run "virsh edit <instance-id>" on the hyprvisor node, and adding below into instance xml just before </domain>.
You're modifying the guest definition behind Nova's back, so you get to keep all the pieces if something breaks. :-)
However, the <qemu:commandline> part is ignored and not saved after closing virsh edit, seems that libvirt rejected these changes. Is there any XML syntax error here? Or libvirt doesn't support <qemu:commandline> tag?
<qemu:commandline> <qemu:arg value='-set'/> <qemu:arg value='device.drive-virtio-disk0.x-data-plane=on'/> </qemu:commandline>
-- /kashyap