Some ESXi hosts enter "Not responding" state after the vCenter Server Appliance is migrated to a busy ESXi host

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Some ESXi hosts become Not responding state in vCenter Server and automatically recover within a few minutes.

vCenter Server Appliance (VCSA) was migrated to an ESXi host where CPU or memory resources are overcommitted.

Environment

VMware vSphere vCenter Server 8.0
VMware vSphere ESXi 8.0

Cause

This is caused by performance degradation of the vCenter Server due to resource contention.

Resolution

To free up resources, perform one of the following actions on the ESXi host where the VCSA is running:

• Migrate other virtual machines to available ESXi hosts with adequate resources.
• Shut down some virtual machines (if they are not critical).

Another workaround is configuring full CPU and memory reservations for the VCSA.