Re: windows domU disk performance graph comparing hvm vs stubdom vs pv drivers

[Keith Coleman <list.keith@scaltro.com>]

On Mon, Feb 22, 2010 at 12:27 PM, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> On Mon, 22 Feb 2010, Keith Coleman wrote:
>> On 2/22/10, Stefano Stabellini <stefano.stabellini@eu.citrix.com> wrote:
>> > On Fri, 19 Feb 2010, Keith Coleman wrote:
>> >> I am posting this to xen-devel instead of -users because it paints an
>> >> incomplete picture that shouldn't be the basis for deciding how to run
>> >> production systems.
>> >>
>> >> This graph shows the performance under a webserver disk IO workload at
>> >> different queue depths. It compares the 4 main IO methods for windows
>> >> guests that will be available in the upcoming xen 4.0.0 and 3.4.3
>> >> releases: pure HVM, stub domains, gplpv drivers, and xcp winpv
>> >> drivers.
>> >>
>> >> The gplpv and xcp winpv drivers have comparable performance with gplpv
>> >> being slightly faster. Both pv drivers are considerably faster than
>> >> pure hvm or stub domains. Stub domain performance was about even with
>> >> HVM which is lower than we were expecting. We tried a different cpu
>> >> pinning in "Stubdom B" with little impact.
>> >>
>> >
>> > What disk backend are you using?
>>
>> phy, LV
>>
>
> That is strange because in that configuration I get a far better
> disk bandwidth with stubdoms compared to qemu running in dom0.
>

What type of test are you doing?


Keith Coleman