Host connection and power state alarm due to ACPI power button event on ESXi

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

An ESXi host shows a "Host connection and power state" alarm in vCenter Server. This occurs when the host initiates a graceful shutdown sequence that severes management connectivity before the host fully powers off.

Symptoms

• The ESXi host status changes to "Not Responding" or "Disconnected" in the vSphere Client.
• The alarm "Host connection and power state" is triggered.
• Virtual machines on the affected host are shut down or high availability (HA) is triggered.
  
  

vmkernel.log:
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YYYY-MM-DDTHH:SSZ In(1**) vmkernel: cpu0:20****)VMKAcpi: 305: Power button pressed; requesting graceful shutdown and poweroff
YYYY-MM-DDTHH:SSZ In(1**) vmkernel: cpu4*:89****)Deactivating Daemon vsan-shutdown. (...shutdown sequence continues...) 

Environment

• VMware vSphere ESXi 7.x
• VMware vSphere ESXi 8.x
• VMware vCenter Server 7.x
• VMware vCenter Server 8.x

Cause

The ESXi host received an ACPI hardware power button signal (physical or virtual).
This signal triggers the VMKAcpi module to request a graceful shutdown, deactivating the management daemons (vpxa and hostd) before the network connection is terminated.

Resolution

 Investigate the source of the power button event to determine if it was a physical action or a remote command.