VM does not fit into one NUMA with half count of hyper-threading

Products

• VMware vSphere ESXi

Issue/Introduction

When a VM with vCPU count over cores number of a socket, the vCPUs are separated on two sockets.

Environment

ESXi 8.0.x

ESXi 7.0.x

Cause

By default NUMA optimization does not count the HTs when determining if the virtual machine could fit inside the NUMA home node. So the facts is a expected behavior.

Resolution

Configure one or all virtual machine to use hyper-threading with NUMA, refer to KB "Configure virtual machines to use hyper-threading with NUMA in VMware ESXi"

Additional Information

https://knowledge.broadcom.com/external/article?articleNumber=326180