I am trying to evaluate VMWare's ESXi 4.1 Hypervisor for a project my company is planning, but am having some trouble find information and wondered if anyone with some experience can shed some light!

We are hoping to use the hypervisor to run a collection of VM's and vSwitches in very specific configurations. I am happily able to configure the VM's and vSwitches through the vSphere app, and have so far been impressed with the product.

We were however hoping to be able to let engineers have access to the VM's, but the problem is they would need to reconfigure the vSwitches and which VM's were active, and we would like to be able to make this transparent to them in as far as they should be able to run a small app, point it at the ESXi host IP, select a configuration, and let the app make the changes needed.

We are currently using the free edition while we evaluate whether this is the correct product for our needs.

When I have been trying to use the SDK, it doesn't seem to be allowing write access!

I am not looking to do anything other than functions provided within the vSphere app, just to start/stop VM's, and to create/destory vSwitches (which are only very basic anyway!)

Can anyone tell me if: A) this is possible with the free edition of ESXi B) do-able through the vSphere API (the docs say so, but the examples won't work) C) Why the vSphere app can do it, but i cant!!!


The free version of ESXi does not allow write access to the API. I am assuming you put the ESXi license you received in, and are not running in eval mode anymore? Reinstall ESXi and don't put your license in. I am pretty sure Eval mode will allow write access to the API.


A vSphere eval DOES allow write access to the API, but requires installing vCenter.

The other option for coding against the API is SimDK.

  • Do you know the most basic license version that would allow write access? How does the vSphere app do it on the basic free license? – BParker Apr 21 '11 at 8:33
  • Eval mode does allow write access. @BParker You'll need to purchase the Standard version of vSphere for write access (vmware.com/products/vsphere/buy/editions_comparison.html). I'm guessing they have some key that allows them write access to the servers without it being licensed. – Scott Keck-Warren Apr 21 '11 at 12:09
  • @Scott Aww, thats a shame... @BParker The only other thing I can think of is SimDK, which is a vSphere 4 API simulator, but it's functionality is not quite 100%. akutz.wordpress.com/2010/03/11/a-simdk-virtual-appliance – JakeRobinson Apr 21 '11 at 14:25
  • @Scott He could also do a vSphere eval, which DOES allow write access to the API. That's how I do my training labs. – JakeRobinson Apr 21 '11 at 14:34

I'm sorry but I don't know too much about the free version but certainly you can script this kind of thing via vCenter or the various APIs, perhaps even using Orchestrator.

If you can be a bit more specific about exactly what you want to do then we may be able to help you further.

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