On Thu, Jun 16, 2011 at 8:29 AM, Stefan Hajnoczi <stefanha@xxxxxxxxx> wrote: > On Wed, Jun 15, 2011 at 11:04 PM, Anthony Liguori <anthony@xxxxxxxxxxxxx> wrote: >> On 06/15/2011 03:13 PM, Prasad Joshi wrote: >>> >>> On Wed, Jun 15, 2011 at 6:10 PM, Pekka Enberg<penberg@xxxxxxxxxx> wrote: >>>> >>>> On Wed, Jun 15, 2011 at 7:30 PM, Avi Kivity<avi@xxxxxxxxxx> wrote: >>>>> >>>>> On 06/15/2011 06:53 PM, Pekka Enberg wrote: >>>>>> >>>>>> - Fast QCOW2 image read-write support beating Qemu in fio benchmarks. >>>>>> See >>>>>> the >>>>>> following URL for test result details: >>>>>> https://gist.github.com/1026888 >>>>> >>>>> This is surprising. How is qemu invoked? >>>> >>>> Prasad will have the details. Please note that the above are with Qemu >>>> defaults which doesn't use virtio. The results with virtio are little >>>> better but still in favor of tools/kvm. >>>> >>> >>> The qcow2 image used for testing was copied on to /dev/shm to avoid >>> the disk delays in performance measurement. >>> >>> QEMU was invoked with following parameters >>> >>> $ qemu-system-x86_64 -hda<disk image on hard disk> -hdb >>> /dev/shm/test.qcow2 -m 1024M >> >> Looking more closely at native KVM tools, you would need to use the >> following invocation to have an apples-to-apples comparison: >> >> qemu-system-x86_64 -drive file=/dev/shm/test.qcow2,cache=writeback,if=virtio > > In addition to this it is important to set identical guest RAM sizes > (QEMU's -m <ram_mb>) option. Right. > If you are comparing with qemu.git rather than qemu-kvm.git then you > need to ./configure --enable-io-thread and launch with QEMU's > -enable-kvm option. I think Prasad is testing qemu-kvm.git. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
