Error: "Two filesystems with the same UUID have been detected" on ESXi host PSOD screen
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Error: "Two filesystems with the same UUID have been detected" on ESXi host PSOD screen

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Article ID: 342372

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Updated On: 02-13-2025

Products

VMware vSphere ESXi

Issue/Introduction

  • An ESXi host fails to boot successfully.
  • PSOD screen displays following error:

    Two filesystems with the same UUID have been detected. Make sure you do not have two ESXi installations.
     
  • The VMkernel log leading up to the outage contains an event similar to:

    Detected duplicate UUID file-systems on device ' naa.600508b1001c37d1e432b12f7b62f6bc:8' and ' naa.60060160f3542900122babfb5160e011:8'

  • This issue can occur when ESXi is installed on both the local hard disk drive and a USB drive

Cause

This issue occurs when a duplicate ESXi installation is detected on a disk presented to the ESXi host. Specifically, this issue occurs when two FAT-16 filesystems exposed to the ESXi installation have the same UUID. This may be the result of a broken mirror or due to previous activity cloning the disks which contain an ESXi installation.

Resolution

Note: This issue is most likely to be seen during startup of an ESXi host. It may be necessary to remove or un-present recently-added disks before troubleshooting can begin.

To resolve this issue, identify the two disks cited by ESXi as containing the duplicate filesystem UUID, and remove one of them.
  1. Restart the system.
  2. During the reboot, when the hypervisor screen appears, press Shift+O.
  3. In the boot option, type 

    overrideDuplicateImageDetection 

    and press Enter.

  4. After the system starts, use any one of these methods to remove the duplicate ESXi installation:
    1. Identify the drive to be remove and run this command from the console:

      # dd if=/dev/zero of=/dev/disks/mpx.vmhba1\:C0\:T0\:L0 bs=1m conv=notrunc

      For more information, see Identifying disks when working with VMware ESX.

    2. Initialize the disk from the BIOS of the SCSI controller, if available.
    3. Install other guest operating systems on the disk that contains the duplicate installation of ESXi.
    4. Use the vSphere Client to add the datastore to another ESXi/ESX host and format the disk (volume) that contains the duplicate installation.

Additional Information

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