Re: [ovirt-devel] high performance VM preset
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(a)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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