ESXi Host Not Responding in vCenter due to 100% CPU Utilization

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi host status displays as Not Responding in the vSphere Client.
• Host CPU utilization is at or above 100% pinning.
• Virtual machines remain operational but show as disconnected from vCenter.
• DRS fails to migrate workloads, and vCLS health may report as unavailable.

Environment

• VMware vCenter Server 8.x
• VMware ESXi 8.x

Cause

This condition occurs due to Management Starvation. When physical CPU resources are fully saturated, management agents (vpxa and hostd) cannot process heartbeat signals or management requests. This prevents vCenter from communicating with the host and impairs HA/DRS functions.

Resolution

1. Log into the server's out of band management (iLO, iDRAC, CIMC, etc) and launch the console to gain access to the VMware ESXi DCUI.
2. Switch to the console by pressing ALT+F1.
3. Restart management agents with the following commands:
   
   /etc/init.d/hostd restart
/etc/init.d/vpxa restart
   
   
4. If the host is completely locked, perform a physical hard power reset.
5. Once the host is back online, verify vCLS health for the cluster to ensure HA and DRS are fully functional.
6. Identify and remediate the VM or process causing the initial CPU spike to prevent recurrence.

Additional Information

ESXi host not responding or disconnected - VMware vSphere

ESXi host not responding due to management starvation and 100% CPU utilization

Accessing DCUI/Console of ESXi using ALT+F Keys

Contact Broadcom support