How to use vCenter Orchestrator to reduce your template maintenance overhead

When I choose to blog about this workflow I was bit hesitant if it is going to be really any value add to my readers. This is the extension of previous blog and it related to custom property post which I had done earlier. In custom property I raised the concern that with clone workflow you have very limited choice. As I explore in depth about integrating vCenter Orchestrator and vCenter Cloud Automation Center I found a better way to do. Clone workflow is the best workflow but vCloud Automation Center by default provides a limited customization it. I have not inclination to get into deploy mechanism of each and every OS e.g. WIM or any other method. So any thing extra I can do with cloning will be always a value add. In this post I explore this pain point.

You must have had heard VM sprawl. Have you heard of Gold templates sprawl. I have experienced it a lot. We created as many VM template as we had service type and again for each OS. Currently our VM sizing looks like below


There are total nine templates I have to maintain. Maintenance includes patching these VMs every time new patches are released. This is very common problem with MS OS. Upgrading VM tools, Upgrade VM hardware. If either of this is left it created huge incompliance in VM hardware, vmware tools and patches.

We always have searched a better solution for this. One was to use PowerShell but it was really clumsy and support was not using it at all.

Using this post I also wish to focused on resolving this problem.

Support wanted a complete automated method where in either end user (non-IT) provision the VM and he gets the VM as per the size he has selected or IT provision them

So they were looking for end to end automatic provisioning a VM without any additional effort to customize the existing deployment method. Cloning was the only option. So I felt cloning existing VM and changing the CPU, Memory and Disk size would be the best way to resolve it. vCenter Orchestrator is wonderful product. It just helps you do it without any effort as long as you know the tips and tricks about it.

All the Workflows are in-built in vCO. All I did is put them in right place.


Crux of this entire workflow is script section.


Script section is very simple. Let me explain it you

First I created a input parameter by name VMService. I have added property to it with pre-defined answers Large, Medium and Small. This create a drop down menu where user selects VM size

Second I created three attributes by name. Remember attributes gets there value from somewhere else

  1. vmNbOfCpus (type number)
  2. vmMemorySize (type number)
  3. AdditionalDisk (type number)

I used “If else” loop. So when user select VMService as Large, script under curly bracket will be executed i.e. it is take value for vCPU=4, MemorySize=4096MB and Disk size=40 GB. All I have to pass these values to next workflow. In this case they are

  1. ChangeCPUcount gets vmNbOfCpus  as 4
  2. ChangeRAM gets vmMemorySize as 4096 MB
  3. Add Data disk gets 40 GB
  4. Change the custom attribute

End User gets below screen to provision VM. Just select IP address, VM Name and Size of the VM. That is all end user has to worry. VM will be ready within 15-20 minutes.


Below is the example of workflow logs


And Below is the example of VM which was created.


As part of workflow I also added custom attribute to VM based on the size created. VM size provisioned below is Medium.


This has been achieved using vCenter Orchestrator Video training available freely at this location.

If you wish to integrate this workflow with vCloud Automation Center you should use advance workflow designer feature. I have discussed it here. Process is more or less similar.

Note: In cloning workflow vim3WaitDnsNameInTools was behaving abnormally. This action element reads DNS name of the VM. Once it read DNS name of the VM using VMware tools, it takes this as trigger to end sysprep operation and proceed next workflow. In my case I got quite varying results. While searching a bit I came across new plug-in introduced for vCenter 5.5.1. Please use latest plug-in which is right now under Technical Preview as I post this.

5 thoughts on “How to use vCenter Orchestrator to reduce your template maintenance overhead”

  1. Hi Preetam – How do you get the VC:VirtualMachine value for the “Add Custom attribute” workflow input? (Which workflow/element do you pass it from?)

  2. Hi Pritam, I have one requirement of increasing a number of vCPU from 2 to 4 for a VM, every month 10th date. How should i do this automate this using vCO. Your pointers would be helpful. Thank you.

    1. Hi Vijay,

      I’m glad you liked the post and found it useful. You will need a schedule a workflow do this. Scheduling workflow is very easy.

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