Hi,

Sorry for the late reply.

The recommended setting for High Performance VMs is generally depended on many parameters and on what your VM is required to do (I/O or compute load), but generally and based on the setting that you sent then I have few comments for configuration tuning:

Host's NUMA pinning topology - can you please send your host's NUMA topology? I can see that the host is set to have 2 NUMA nodes (2 sockets) with 20 CPUs in each NUMA node, but how those CPUs are divided among the NUMA nodes?

An example for host's NUMA topology can be:

NUMA node0 CPU(s): 0-19

NUMA node1 CPU(s): 20-39

Virtual NUMA pinning topology - currently I can see that you set your VM to run with 8 virtual NUMA nodes while your host is configured to run with only 2 physical NUMA nodes. I recommend you to change the "NUMA Node Count" value to 2 since there is no reason to set number of virtual NUMA nodes bigger than the number of physical NUMA nodes.

Then, please click on "NUMA pinning" button in UI and pin virtual NUMA0 to "Socket 0" and virtual NUMA1 to "Socket 1" or vice versa (the order depends on your CPU pinning settings which is detailed in next bullet).

CPU pinning topology - your current CPU pinning is set to: "0#0_1#1". This means that virtual CPU0 is pinned to physical CPU0 and virtual CPU1 is pinned to physical CPU1. But what about other VM's six VCPUs?

Therefore, I recommend you to set your "CPU pinning topology" field such that each one of the 8 virtual CPUs is pinned to a physical CPU:

The first four virtual CPUs CPU0-vCPU3 will be pinned to 4 physical CPUs within the first host's NUMA node (i.e. CPUs in Socket 0).

And the other group of four virtual CPUs vCPU4-vCPU7 will be pinned to four CPUs in second host's NUMA node(i.e. CPUs in Socket 1).

There are other recommended settings for VM performance improvements like setting Huge pages for the VM (via the "Custom Properties" tab) but that requires your host to support huge pages as well.

Regards,

Sharon

On Thu, Aug 15, 2019 at 1:14 AM Vincent Royer <vincent@epicenergy.ca> wrote:

Haha, oh. Don't I feel dumb. So all the settings are good then?

On Wed, Aug 14, 2019, 2:07 PM Oliver Riesener <Oliver.Riesener@hs-bremen.de> wrote:
Hi Vincent,

nice setup. ;-)

The column %guest with (800% or 20% of all) locks good for me.
The rest cores are %idle.

Best regards

Oliver

Am 14.08.2019 um 10:04 schrieb Vincent Royer <vincent@epicenergy.ca>:

Is there a good place to learn about cpu pinning and the various settings?

I've built a test VM and am trying to understand

- I've given it 2 cpus, 4 cores each, 1 thread per core.
- The VM is pinned to a specific host with passthrough cpu enabled
- numa pinning, first 4 cores on physical socket 1 and the next 4 on physical socket 2
- The host has two sockets each with 20 core cpus

I would expect to see a load applied on 8 of the 40 cores on the host during testing. Instead it seems like 32 of 40 cores are working at 100%. What are the effects of this on the performance of the vm?

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