The DCUI screen of an ESXi host booting from an SD card or SAN is stuck at error "Using 'simple offset' UEFI RTS mapping policy"
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The DCUI screen of an ESXi host booting from an SD card or SAN is stuck at error "Using 'simple offset' UEFI RTS mapping policy"

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Article ID: 413631

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

  • When attempting to access the DCUI console of an ESXi host, it remains stuck at the following error.

Shutting down firmware services...
Using 'simple offset' UEFI RTS mapping policy

Environment

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

Cause

  • The root cause of this issue is typically related to an incompatibility or an issue with the server's firmware (BIOS) in conjunction with the UEFI Runtime Services (RTS) used by the ESXi operating system. UEFI Runtime Services are the functions provided by the UEFI firmware that ESXi utilizes after the initial boot sequence is complete.

Resolution

Important Note: Before implementing any of the following steps, it is highly recommended to contact your hardware vendor to obtain and install the latest firmware (BIOS) update for your physical server. This is the preferred solution, as it addresses the underlying cause of the problem.

If the latest BIOS is installed and the issue persists, use the following workarounds:

 

For ESXi 8.0U2 and later:
A hotkey is provided to disable UEFI RTS.
  1. Reboot the ESXi host [1].
  2. As the hypervisor progress bar begins loading, press the Shift+U hotkey.
  3. Ensure you press Shift+U while the bar is actively loading, not after it has completed.

 

For ESXi versions prior to 8.0U2:
This method involves modifying the ESXi installer image to permanently disable UEFI RTS.
  1. Download the ESXi ISO: Obtain the installation ISO file for the exact same ESXi version and build that is currently installed on your host.
  2. Mount the ISO on a Linux machine:
    • Create a mount point: mkdir /mnt/esxi_cdrom
    • Mount the ISO: mount -o loop <path_to_ESXi_ISO.iso> /mnt/esxi_cdrom
  3. Copy the ISO contents: Copy all files and folders from the mounted ISO to a new working directory: cp -r /mnt/esxi_cdrom/* /esxi_custom_image
  4. Edit the boot configuration:
    • Navigate to your new working directory: cd /esxi_custom_image
    • Edit the boot.cfg and /efi/boot.cfg files.
    • Add the line norts=1 to the kernelopt line in both files.
    Example boot.cfg snippet: 
    bootstate=0
title=Loading ESXi installer
timeout=5
prefix=http://<server>/os/esxi/7
kernel=b.b00
kernelopt=runweasel ks=http://<server>/os/esxi/7/ks.cfg norts=1
modules=jumpstrt.gz ...
build=7.0.2-0.0.17867351
updated=0
  5. Recreate the ISO image: Use either mkisofs or genisoimage to build a new, customized bootable ISO.
    • Using mkisofs:
      mkisofs -relaxed-filenames -J -R -o custom_esxi.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -eltorito-alt-boot -eltorito-platform efi -b efiboot.img -no-emul-boot /esxi_custom_image
    • Using genisoimage:
      genisoimage -relaxed-filenames -J -R -o custom_esxi.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -eltorito-alt-boot -e efiboot.img -no-emul-boot /esxi_custom_image
  6. Boot the host with the new ISO: Boot the ESXi host using the custom_esxi.iso and perform a clean installation or repair.

If the issue persists even after applying these workarounds, it indicates a deeper hardware or firmware-related problem. In this scenario, it is necessary to engage with your hardware vendor for further diagnostics and a potential reinstallation of ESXi.

Additional Information

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