Device marked as 'Dead or Error' in the ESXi host

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms

• A device connected through controller vmhba4 is in a dead or error state. The affected device type is SCSI processor.

  

• Another device connected via the same vmhba4 adapter is a disk in active state; this disk is the boot LUN.

• No operations or commands can be successfully initiated on the ESXi host.

• Log files on the ESXi host are inaccessible. These logs are stored on the boot LUN.

• Running the command esxcfg-mpath -b on the ESXi host shows that the target is unavailable.

  

Environment

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

The issue is due to a hardware failure of the vmhba4 (BOSS) controller on the affected ESXi host. The controller is not detected by the host, preventing access to the associated disks.

Cause Validation

On the impacted ESXi host’s iDRAC, the BOSS controller is not visible

As the controller is not detected, SSD 0 and SSD 1 (configured under the BOSS controller) are missing from the physical disk list. Consequently, the virtual disk created using these two SSDs which serves as the Boot LUN is also missing. 

In comparison, the iDRAC view from a healthy host shows the BOSS controller, its associated SSDs, and the virtual disk correctly detected.

Resolution

Engage your hardware vendor to investigate and resolve the issue with the BOSS controller on the affected ESXi host. The controller is currently not detected, which results in the Boot LUN (OS disk) being unavailable.

Note: The ESXi host is currently operating from cached memory. Do not reboot the host at this time, as the OS may fail to load due to the missing boot disk. Resolution of the hardware issue is required before any reboot or further action is taken.