VMware Tools installation fails with "vix error code =21001"

Products

• VMware vSphere ESXi
• VMware vSphere ESXi 8.0

Issue/Introduction

• Installing VMware Tools on virtual machine fails with below error:
  
  The required VMware Tools ISO image does not exist or is inaccessible.
vix error code = 21001
The VMware Tools image is inaccessible. Unable to install VMware Tools An error occurred while trying to access image file "/usr/lib/vmware/isoimages/windows.iso" needed to install VMware Tools:5 (input/output error). Please refer the product documentation or KB article 2129825 for details about how to get VMware Tools package for this guest operating system.
  
  
• Below symbolic links appear invalid/broken when checking from ESXi host command line:
  
  locker -> /var/lib/vmware/osdata/locker
productLocker -> /locker/packages/vmtoolsRepo
  
  
• The ESXi host is having some issue accessing local datastore and the symbolic link to local datastore also appears broken. 

Environment

VMware vSphere ESXi 8.0

Cause

There's issue with access to local datastore which also causes the location of VMware Tools package to be inaccessible.

Resolution

Engage hardware vendor to check and confirm if there's any hardware issue on the host.

If ESXi host fails to boot up after a reboot,  an ESXi host reinstall would be required.