One of the best parts of VMware vSphere is that you can experiment with vSphere features without dedicating a lot of dedicated hardware. Specifically, vSphere can be virtualized within itself. This means you can run ESXi (the hypervisor for vSphere) as a virtual machine itself. This is a great tool for testing new features, permissions, configuration arrangements, upgrades to the latest versions and more.

One of the biggest irritants with this process is that the VM that was running ESXi didn’t run VMware Tools. VMware Tools is the guest enlightenment kit in terms of drivers and interaction with the host. With the latest VMware Fling project, we can now install VMware Tools on VMs that run ESXi.

In conjunction with this, we are also in good shape on modern VMware hypervisors in that there is a defined guest operating system type of VMware ESXi 5.x. This is a great step forward from all of the previous steps needed to take a x64 Red Hat Linux operating system and morph it with cryptic options to be an ESXi host. In Figure A, you can see that this guest VM is configured as an ESXi operating system, and the VM doesn’t have a report of VMware Tools running.

Figure A

The VMware Fling that installs Tools on the virtualized ESXi host exists as a VIB. A VIB is effectively a software installation module for ESXi; some are produced by VMware; some are made by hardware and software vendors for specific solutions. For VMware Tools, you can run the following command to install the VIB for tools on the VM (Short URLs work as well):

esxcli software vib install -v -f

Once the VIB is installed, the guest VM that is running ESXi will load the VIB during the VIB process. One of my good friends in the virtualization community, Vladan Seget has also written a blogpost on how to make an .ISO out of this process for easy installations where the network may not be connected to the Internet. Read his post here.  In Figure B below you can see the VIB being loaded at the end of the boot process:

Figure B

At that point, the ESXi host can run Tools and function like a well-behaving VM with any others that may be in use. It’s important to note that running ESXi as a VM in this fashion is not a production-class solution; it’s made specifically for test environments.

This is a great way to properly prepare for a vSphere upgrade, specifically if you haven’t upgraded from vSphere 5 yet; the change from 5.0 to 5.1 is significant. VMware administrators need proper ways to test these critical upgrades confidently, and this is a great way to help in conjunction with vCenter Server and possibly a virtual lab to isolate it all.

Have you jumped on the VMware Tools fling for nested ESXi yet? How has it gone for you? Share your comments below.