Configure virtual machines to use hyper-threading with NUMA in VMware ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

 NUMA settings can change on a per host or per virtual machine basis in ESXi hosts verion 4.1.x and newer

For memory latency sensitive workloads with low processor utilization or high interthread communication, use hyper-threads with fewer NUMA nodes instead of full physical cores spread over multiple NUMA nodes.

Configure virtual machines to use hyper-threading with NUMA.

Environment

VMware vSphere ESXi

Resolution

Perform either of the following tasks:

• Configure one virtual machine to use hyper-threading with NUMA, add numa.vcpu.preferHT=TRUE for per-virtual machine advanced configuration file.
  
  To edit with vSphere Client:
  1. Right-click on VM
  2. Select Edit Settings
  3. Click the Options tab.
  4. Highlight General under Advanced options and click Configuration Parameters.
      
• Configure all virtual machines to use hyper-threading with NUMA, add numa.PreferHT=1 for per-host advanced configuration file.
  
  To edit from vCenter Server:
  1. Highlight Host.
  2. Click the Configuration tab.
  3. Under Software, click Advanced Settings.
  4. Highlight Numa and browse to Numa.PreferHT.