Updating VMware vSphere Hypervisor

So first post about the free Hypervisor under its new name.

I wrote an article regarding the process of upgrading from ESXi 3.5 to ESXi 4.0.

Well I am happy to announce that this has changed - again! Have you tried to find the VMware vSphere Host Update Utility? It was never downloadable - it was part of the vSphere Client which was bundled with your ESXi Installation.(by the way that has also been removed from the installation and is not a separate download as well.

What once was


Is now..


The reason that the download is actually almost 160MB larger with less inside is a mystery to me (I guess the multiple languages now built in - make it a lot larger). But there is no Host Update utility any more.

The general consensus is that that VMware are pushing for Central Management - which means you need to use Update Manager - which is only part of the vCenter Package.

If you still want to update your hosts you will have to revert to a bit of command-line work.

The solution to this in the Upgrade Guide.

What you will need is:

  1. A Scratch Partition on your ESXi host

    You must configure a scratch partition and reboot the host before proceeding with the upgrade.
    You can configure a scratch partition for a host under the Software Advanced Settings in the Configuration tab of the vSphere Client.

    What is the Scratch Partition?

    During the autoconfiguration phase in the Host installation process, a 4GB VFAT scratch partition is created if the partition is not present on another disk. When ESXi boots, the system tries to find a suitable partition on a local disk to create a scratch partition. The scratch partition is not required. It is used to store vm-support output, which you need when you create a support bundle. If the scratch partition is not present, vm-support output is stored in a ramdisk. This might be problematic in low-memory situations, but is not critical.

    For ESXi Installable, the partition is created during installation and is thus selected. VMware recommends that you leave it unchanged.

  2. vSphere CLI - Download Here

    Download the tool - For Windows or Linux and install on your workstation.

  3. Download the Upgrade Package for 4.0 to 4.1 or the Upgrade Package from 3.5 to 4.1

  4. Power off your VM’s and put the host into maintenance mode

  5. Change your current directory to C:\Program Files\VMware\VMware vSphere CLI\bin

  6. From the vSphere CLI prompt

vihostupdate.pl --server host name or IP address -i -b location of the ESXi upgrade ZIP bundle -B ESXi410-GA

So in my case

vihostupdate.pl --server msaidelk-esx -i -b c:\temp\upgrade-from-ESXi4.0-to-4.1.0-0.0.260247-release.zip -B ESXi410-GA


You can of course do the same thing with ESX Updates as well

vihostupdate.pl --server host name or IP address -i -b location of the ESXi upgrade ZIP bundle -B ESXi410-GA-esxupdate

A reboot of the host is necessary thereafter.

Happy Upgrading!!

Update 28-08-2010

Updated the syntax to include the .pl extension to the command and added Step 5.