Re: [Qemu-devel] virtio-blk throughput

[Prateek Sharma]

On Mon, Feb 13, 2012 at 4:53 PM, Stefan Hajnoczi <address@hidden> wrote:
> On Sat, Feb 11, 2012 at 9:57 AM, Prateek Sharma <address@hidden> wrote:
>> $QEMU  -cpu core2duo,+vmx  -drive file=$VM_PATH,if=virtio,aio=native
>> -drive file=viotest.img,if=virtio,index=2
>
> -drive cache=none is typically used for good performance when the
> image is on a local disk.  Try that and I think you'll see an
> improvement.
>
> Stefan

Hi Stefan,
    I did try setting cache=none in one of the runs, and saw a small
performance *drop* for sequential reads. Could it be because of the
host page-cache read-ahead and other factors?
    In any case, i just wanted to know what the current qemu
virtio-blk numbers are, and whether i have misconfigured things badly.
    What is the "fastest" way to do IO in qemu? virtio-blk, vhost-blk,
virtio-dataplane, something else?
    Thanks!