ESX/ESXi ISO installer failed to show installation wizard due to "isolinux disk error 20"

Products

• VMware vSphere ESXi

Issue/Introduction

• When booting from ESX/ESXi ISO installer, a console display show error like this.
  

  isolinux disk error 20, AX = 42B6, drive EF
  Boot failed: press a key to retry...

• Same ISO file can be used normally for another Server and is not corrupted.

Environment

VMware vSphere ESX
VMware vSphere ESXi

Cause

"isolinux disk error 20" indicates Int13 interrupt call for reading ISO media failed with Controller failure. Since Int13 is implemented as a part of BIOS/UEFI/FW, it should be handled by hardware vendor.

# https://en.wikipedia.org/wiki/INT_13H
20h	Controller failure

It's unlikely to be either a software issue or a typical hardware failure; it might be a compatibility problem.

Resolution

Engage a hardware vendor to investigate why int13 interrupt call, including checking a server/bios/uefi compatibility.