Error: ESXi host powers off unexpectedly via ACPI signal

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi host becomes unresponsive
• The host enters a powered-off state.
• vSphere logs (vmkernel, vobd) do not indicate a software-triggered shutdown.
• The following error is observed in var/run/log/hostd.log: The host is being powered off through Advanced Configuration and Power Interface (ACPI). User: UNKNOWN_USER.
• The following entry is found in var/run/log/vmkernel.log: VMKAcpi: 305: Power button pressed; requesting graceful shutdown and powerof
• A "soft-off" event is recorded in the IPMI System Event Log (SEL): Record Id: #### When: [TIMESTAMP] Event Type: 111 (Unknown) SEL Type: 2 (System Event) Message: Assert + System ACPI Power State S4/S5: soft-off Sensor Number: ####

Environment

• VMware ESXi 7.x
• VMware ESXi 8.x

Cause

The ESXi kernel received a hardware-layer ACPI shutdown signal. This signal originates outside of the vSphere software stack and is typically triggered by a physical power button press or a command from the Out-of-Band (OOB) management controller (e.g., iLO, iDRAC, XCC).

Resolution

1. Perform a power reset of the ESXi host to restore service.
2. Review the Out-of-Band (OOB) management logs (iLO/iDRAC/CIMC) for the exact timestamp of the shutdown to identify the source of the ACPI signal.
3. Audit physical access to the server chassis to rule out manual intervention.
4. If the trigger source cannot be identified, contact the server hardware vendor to perform diagnostic tests on the motherboard and power supply units.

Additional Information

For more information please refer to Unexpected ESXi Reboot or Shutdown