This blog post is written by Sapan Jain and Krishnaprasad K from Dell Operating System team. 

VMware ESXi versions (Dell customized VMware ESXi 6.0.x) shipped out of Dell factories may expose a failure when users try to upgrade to a higher version using VMware Update Manager (VUM).

The failure would be seen in "Remediate" step in the upgrade process and error code may be similar to "Cannot execute upgrade script on the host". 

This issue will not be seen if users have installed ESXi using Dell customized VMware ESXi images downloaded from (OR) VMware ESXi images posted at 

How do I check the Dell customized version running on my system?

  • Login to vSphere client (HTML client) where you could see a string something similar to “You are running DellEMC Customized Image ESXi 6.0 Update 2 A00”         (OR)
  • Login to VMware ESXi shell console and read the file /etc/vmware/oem.xml


The problem is caused by having upper case letters for the files residing in ESXi file system. For example, you may see that /altbootbank has files of upper case. 



There are no workarounds available which can be used to proceed upgrade when this failure is hit. There is no data loss even though the upgrade is failed, you may boot back to the original ESXi configuration prior to upgrade.  The available options to recover from this failure are as follows:-


1.    Upgrade using Dell iDRAC vMedia/CD Based method.

2.    Use scripted upgrade using PXE infrastructure.

This issue is fixed from the following versions of Dell customized VMware ESXi releases.