[ovirt-devel] high performance VM preset

[Martin Sivak]

> In order to maximize performance we may also want to limit the number of
> other VMs (either regular or high performance) running on the same
> host. This to minimize the interference and the resource stealing.
>
>
> In the extreme case, just the selected high performance VM would be
> allowed to run on one suitable host.

I would base this on cores. You can have two HPF VMs when each is
pinned to distinct set of CPUs.

Martin

On Wed, May 24, 2017 at 2:11 PM, Francesco Romani <fromani at redhat.com> wrote:
> On 05/24/2017 12:57 PM, Michal Skrivanek wrote:
>> Hi all,
>> we plan to work on an improvement in VM definition for high performance workloads which do not require desktop-class devices and generally favor highest possible performance in expense of less flexibility.
>> We’re thinking of adding a new VM preset in addition to current Desktop and Server in New VM dialog, which would automatically pre-select existing options in the right way, and suggest/warn on suboptimal configuration
>> All the presets and warning can be changed and ignored. There are few things we already identified as boosting performance and/or minimize the complexity of the VM, so we plan the preset to:
>> - remove all graphical consoles and set the VM as headless, making it accessible by serial console.
>> - disable all USB.
>> - disable soundcard.
>> - enable I/O Threads, just one for all disks by default.
>> - set host cpu passthrough (effectively disabling VM live migration), add I/O Thread pinning in a similar way as the existing CPU pinning.
>> We plan the following checks and suggest to perform CPU pinning, host topology == guest topology (number of cores per socket and threads per core should match), NUMA topology host and guest match, check and suggest the I/O threads pinning.
>> A popup on a VM dialog save seems suitable.
>>
>> currently identified task and status can be followed on trello card[1]
>>
>> Please share your thoughts, questions, any kind of feedback…
>
> In order to maximize performance we may also want to limit the number of
> other VMs (either regular or high performance) running on the same
> host. This to minimize the interference and the resource stealing.
>
>
> In the extreme case, just the selected high performance VM would be
> allowed to run on one suitable host.
>
> Bests,
>
> --
> Francesco Romani
> Senior SW Eng., Virtualization R&D
> Red Hat
> IRC: fromani github: @fromanirh
>
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