I have received several questions from folks asking if there are other VMware solutions that could work with the vCenter Server Simulator (vcsim) which I recently wrote an article about back in 2012. Well, the answer is I do not know, as other solutions have not really been tested out with vcsim. The goal of vcsim was primarily focused at the vSphere layer and I suspect that other VMware solutions can probably leverage what vcsim has done but probably will not work (today) as some solutions require a fair amount of communication between itself and the vCenter Server. Now having said all that, you might be wondering about the title of this article?

The one solution that I am aware of today that works with vcsim is vCloud Director and this is merely a proof of concept than anything else, so I would like to set the proper (low) expectations. The available functionality from vCloud Director is quite limited when using it with vcsim and I have also ran into several issues which I will go into more detail later. For vCloud Director to be able to consume the simulated inventory from vcsim, a few tweaks are required in both vcsim and the vCloud Director database.

Disclaimer: This is not officially supported by VMware, use at your own risk.


  • VCSA 5.1 (vCenter Server Appliance)
  • VCNS 5.1 (vCloud Networking and Security)
  • VCD 5.1 Appliance
  • configureVCSimulator.sh script

I highly recommend you take a look at my vCenter Server Simulator article before getting started as it gives you some background that is required later on but you will not be required to configure the VCSA in advanced as there are some additional configurations that are needed. I will also be using the vCloud Director appliance which I recommend for quick ease of deployment and setup.


Step 1 - Deploy VCSA and configure it as you would normally (do not touch the vcsim configurations, as that is handled in the next step using a script that is provided)

Step 2 - Download the configureVCSimulator.sh script and upload it to the VCSA. By default, vcsim's XML configuration files is set to ESXi 4.0 and we will need to adjust the version numbers to reflect either 5.0 or 5.1 as well as modify the hypervisor type from embeddedEsx to esx which is required by the simulator code. Go ahead and run the script on the VCSA which will setup the vcsim as well as modify the necessary files. Once the script has completed, if you wish to change the default inventory, go ahead and modify /etc/vmware-vpx/vcsim/model/initInventory.cfg and then restart the vCenter Server service by running service vmware-vpxd restart

Here is a screenshot of the script running:

Note: If you are interested in the files that are being modified, you can take a look at the shell script for more details. 

Step 3 - Deploy and configure VCNS appliance as you would normally. Make sure you also register the vCenter Server in the VCNS UI that you just deployed as this is needed before moving forward to the next step.

Step 4 - Deploy the VCD appliance using the embedded database and power on the system. Once the system is ready, go ahead and SSH to the host, we will need to execute a few SQL queries which will allow vCloud Director to support simulated hosts as well as the particular ESXi versions. First we need to switch over to the Oracle user, run the following command:

su - oracle

Next we will login to the VCD database using sqlplus and the default credentials which should be vcloud/VCloud, run the following command:

sqlplus vcloud/VCloud

The first SQL statement will allow VCD to support simulated ESXi hosts, type in the following SQL statement:

update config set value='1' where name='vzSim50Supported';

The next two SQL statements will define the version of ESXi that VCD will support, type in the following SQL statements that are applicable to you:

insert into os values (seq_config.NextVal, 'vmnix-x86', 'VMware ESX', '5.1.0', 0, 1);
insert into os values (seq_config.NextVal, 'vmnix-x86', 'VMware ESX', '5.0.0', 0, 1);

Finally, we just need to type "quit" to exit from sqplus and then type "exit" to logoff as the oracle user and this will bring us back to root context. The last thing we need to do is restart the vCloud Director service for the changes to go into effect by running the following command

service vmware-vcd restart

Here is a screenshot of running through the VCD database changes:

Step 5 - Once the vCloud Director service has been successfully restarted, we are now ready to setup our vCloud Director Simulator environment. Start off by adding both your VCSA and VCNS to the vCloud Director under Resources tab as you would normally.

Next, click on Provider VDCs to create your Pvdc and when you arrive at the ESXi host preparation step, you can type in anything for the username/password (since these are simulated ESXi host).

After you click next or finish, you then click into the Hosts tab to watch the ESXi host preparation. This is where you will notice the first issue, the preparation should finish almost immediately as thgey are simulated hosts, so no VCD agent is installed or services needing to be enabled, but from what I have seen this process can take up to 30minutes if not longer. You will need to be patient when you get to this point and do not try to cancel the process and just let it sit and finish. To ensure your environment is setup correctly, make sure the following three columns show green check marks: Enable, Ready and Available during the preparation.

This is probably a good time to get some coffee or tea and check out other cool articles on virtuallyghetto.com 😉

Once the ESXi hosts have completed preparation, you should see a green check box under the Status column which means you are now ready to create an Organization which is a pre-requisite before creating an Organization VDC. I will assume you know how to proceed from here and depending if you setup an ESXi 5.0 or ESXi 5.1 environment in vcsim, you will need to choose the appropriate virtual machine compatibility (virtual hardware) to support in your OrgVDC.

Note: If you setup an ESXi 5.0 environment, you may see an error with too many connected datastores, to resolve this, you need to either decrease the number of hosts in your simulated environment or use ESXi 5.1

You can probably guess the last step is to start provisioning VMs/vApps in our vCloud Director instance, but sadly this is where you will face another issue. What I have found is that when you deploy a new vApp, an exception is thrown regarding a NULL pointer and VCD will fail on the deployment.

However, if we take a look at our vcsim environment, you will see that the VM actually does get created but this still poses a problem for us in VCD, as the task is still not considered successful.

I have not been able to figure out why and I know from running through several tests, there was a case where I was able to successfully provision a VM in the VCD simulator. This might be related to the version of virtual hardware selected, I had more luck using either 7 or 8 but not so much with 9. Unfortunately, without provisioning capabilities, this may not be as useful as one would like but I encourage you to still give this a try if you are interested.

The vCloud API can also be access in the simulated environment, but remember that the operations will be limited to what has been shown and will probably work for most of the inventory based API calls, but again, YMMV.

Though vCloud Director Simulator is somewhat limited today and with a few known issues, it is a proof of concept that other VMware solutions can leverage what vcsim has provided as a base foundation. If you think this is something that is useful to have or have other use cases for, please leave a comment. You never know, this could be a VMware Fling one day if there is enough interest from the community.

8 thoughts on “vCloud Director Simulator

  1. My pVDC says there are no usable hosts… thoughts? Also, most likely related, the SQL to insert the OS type failed with an error about violating a unique key constraint. Have you see this?

  2. Did you change the ESXi version in VCSIM? I suspect that you may be using the default from VCSIM which is version 4.x and that’s why you’re seeing that error.

    I’ve not seen the unique key constraint, since “seq_config.NextVal” should handle that for you.

    • Okay, then by default the script should set your ESXi hosts to show up as 5.1. Can you double check that is the case in vCenter? Usually you would see this issue if you used the defaults from VCSIM which is 4.1 and when you created your PvDC and set vHW 8 or 9, it would fail since no available hosts could support that. What vHW did you use when creating the PvDC?

  3. The vCloud Director appliance seems to no longer available for download. Any idea where I could get my hands on it. I really need a safe place to explore vCD APIs and had hoped to add this to the excellent VCSIM.

    • Unless you’re an existing VCD/VCD-SP customer, I suspect its not available anymore per the EOL announcement. You can always try contacting your account team

Thanks for the comment!