Friday I was at a customer to upgrade their ESXi 4.0 (free) to version 4.1.
This should have been an easy task, download CD, burn it and install.

This wasn’t the case, the new ESXi 4.1 wouldn’t install, it kept freezing during the extract of the cim.vgz file.
The problem occurred on both the Dell custom of ESXi 4.0 U1 and the standard ESXi 4.1.
We googled and googled but didn’t find a solution – in the end we blamed the error on the old bios version 1.1.4.

To my luck the customer still had the CD we installed the server with 9 months ago – ESXi 4.0.

We installed ESXi using the old CD and then everything was working – but we still needed to upgrade to ESXi 4.1.

So now what to do …….

Normally you use the hostupdate utility or the Remote CLI but the hostupdate utility is not included in the free version of ESXi and the we didn’t want to install the Remote CLI on the computer.
To my luck I had the hostupdate utility installed but i kept getting this error when trying to upgrade the ESXi host.

“Failed to read the upgrade package metadata.xml”

The solution to our problem was:

  1. Since it was a ESXi free with out support, we decided to use the “ESXi command line interface”, witch is unsupported.
    Follow this guide to enable it (
  2. Download and extract the upgrade ZIP file from VMware.
  3. From the VIclient, upload the extracted files to the host datastore, using the “datastore browser”
    – I uploaded the files to a folder named “upgrade”
  4. Put the ESXi host in “Maintance Mode”
    – Since it is a ESXi, this can only be done when all VM’s are powered off.
  5. Connect the the ESXi console using ex. Putty.exe.
  6. Navigate to the upgrade directory.
    cd /vmfs/volumes/local-datastore/upgrade
  7. Begin the upgrade process
    esxupdate update -m
  8. When the upgrade is finished, reboot the host.
  9. To verify the new build number:
    – Connect to the host using the VIclient
    – Select the host
    – Choose the “Summery” tab
    – Verify that the ESXi version number and build has been updated