Re: Question about performance comparison between virtio-fs and virtio-blk

[Hao Xu]

On 7/26/22 21:17, Vivek Goyal wrote:
> On Tue, Jul 26, 2022 at 08:55:38AM -0400, Stefan Hajnoczi wrote:
> > On Tue, 26 Jul 2022 at 08:24, Hao Xu <hao.xu@linux.dev> wrote:
> > > I watched your presentation about virtiofs in 2020,
> > >
> > > https://www.youtube.com/watch?v=EIVOzTsGMMI&t=232s
> > >
> > > which is really helpful to me, but I have a question about the graph at
> > > 3:53, could you give
> > >
> > > me more info about the test, like what tool you use for the test, if
> > > it's fio, what is the parameters.
> > >
> > > I used fio to do randread test in a qemu box, but turns out the iops of
> > > virtio-blk and virtio-fs are similar.
>
> Hi Hao,
>
> My impression in general is that virtio-blk is much faster than virtiofs.

When testing virtio-blk, did you use the device directly or mount it and
test against a file.

> A simple macro test is do a kernel compilation and compare time taken
> between the two.

Good idea, I just tested with single file.

Thanks,
Hao

> > I have CCed Vivek Goyal, who has done more virtiofs benchmarking and
> > might have ideas to share.
> >
> > The benchmarking tool was fio with the stated blocksize and I/O
> > pattern. The benchmark was probably run with direct=1. Based on the
> > virtio-blk numbers I think iodepth was greater than 1 but I don't have
> > the exact fio job parameters.
>
> I had basically used fio jobs. I wrote some simple wrapper scripts to
> run fio and parse and report numbers.
>
> https://github.com/rhvgoyal/virtiofs-tests
>
> I don't have data for virtio-blk but I do seem to have some comparison
> numbers of virtiofs and virtio-9p.
>
> https://github.com/rhvgoyal/virtiofs-tests/tree/master/performance-results/feb-23-2021
>
> Thanks
> Vivek