Host randomly rebooted

Products

• VMware vSphere ESXi

Issue/Introduction

/var/log/vmksummary.log does not display:

Host is rebooting

/var/log/hostd.log does not display:

The host is being rebooted through the Direct Console User Interface (DCUI)

/var/run/log/vmksummary.log only displays:

Host has booted

/commands/localcli_hardware-ipmi-sel-list--p--i--n-all.txt displays:

Record:263:
   Record Id: 263
   When: 2025-08-17T16:24:35
   Event Type: 111 (Unknown)
   SEL Type: 2 (System Event)
   Message: Assert + System Event OEM System boot event
   Sensor Number: 0
   Raw:
   Formatted-Raw: 07 01 02 43 02 a2 68 01 00 04 12 00 6f 01 ff ff

Environment

8.x

Cause

The Assert + System Event OEM System boot event error indicates a hardware issue with the physical ESXi host. 

Resolution

• The Servers abrupt reboot or shutdown without user intervention could be due to one or more of the following:
  • Hardware Issue(s)
  • BIOS settings with Automated server recovery
  • User Interaction
  • Physical Infrastructure related
  • Third party calls using API etc
• Recommended to review/test the hardware with the vendor.