Unable to increase vCPU though hot plug when enabled on the VM in vCenter

Products

• VMware vSphere ESXi

Issue/Introduction

When attempting to increase CPU on a powered-on Virtual Machine using the hot-plug functionality, the operation fails with the following error:

The operation Resize failed. Error from vCenter: The hot-plug operation failed

Environment

VMware vSphere 8.0 (vCenter)

Cause

The vCPU Count cannot be greater than the Cores per Socket setting. Exceeding this ratio triggers a socket-limit error during the hot-plug operation.

Resolution

This behavior is expected. The vCPU Count cannot exceed the Cores per Socket value during a hot-plug operation.

Note: To increase the CPU resources beyond the current Cores per Socket limit, you must first power off the Virtual Machine to modify the socket topology.

Additional Information

• Configure the CPU Topology of a Virtual Machine 
• Enable CPU Hot Add