[CentOS-virt] performance differences between kvm/xen

Thu Oct 28 15:11:21 UTC 2010
Todd Deshane <deshantm at gmail.com>

Hi Grant,

On Wed, Oct 27, 2010 at 11:00 AM, Grant McWilliams
<grantmasterflash at gmail.com> wrote:
> Todd, I think there's more than one way to look at this as well. As Xen
> becomes more of a product and less of an installable package
> it will probably have to be profiled as a product.

The XCP devs hope that XCP will eventually be available via a package
install (for example something similar to yum install xcp).

> Say benchmark XCP on
> particular hardware and benchmark RHEL KVM on the same hardware and ESX as
> well.
> It makes sense to benchmark a XEN kernel and a KVM kernel if we have that
> flexibility but that's starting to shrink. Another test that I don't think
> is THAT important anymore is tesing Xen with and without pvops kernels.
> There were some rumors going around that the old 2.6.18 kernel was faster
> than the new pvops. I was going to put together tests and never got to it.
> Not that it makes any difference in the future because the old kernel is
> fast going
> away.

Yeah the old one is going away, comparing the forward port kernel (for
example from OpenSUSE) to the new pv_ops one is what we will want to
do. The pv_ops one may be better or worse under certain loads, but
unless we test, how will we know? Once we can demonstrate it, the
pv_ops kernel can be improved as needed too.

> What I'd like to have is a standardized test with a way of multiple people
> uploading it and comparing results so we can run it on as many systems as
> possible.
> Data correlation could then be done on the data. Currently we have one test
> over here and another over there and the tests never seem to be updated or
> even
> run again to verify results. Maybe none of it matters as the hypervisor
> becomes inconsequential.

Great, yes that is what research at Clarkson University tried to do.
As far as I know no one at Clarkson is actively working on it though.
I will check with them when I get a chance though.

> I'm going to look at the tests you've done as soon as time permits.

What we completed were some basic things. There is still more to test.


Todd Deshane