You can automate repetitive tasks by running a workflow on a selection of objects. For example, you can create a workflow that takes a snapshot of all the virtual machines in a virtual machine folder, or you can create a workflow that powers off all the virtual machines on a given host.
You can use one of the following methods to run a workflow on a selection of objects.
- Run the workflow.
- Create a workflow that calls the Start workflows in parallel workflows. or
- Create a workflow that obtains an array of objects and runs a workflow on each object in the array in a loop of workflow elements.
Which method you choose to run a workflow on a selection of objects depends on the workflow to run and can affect the performance of the workflow. For example, running the Run a workflow on a selection of objects workflow is the simplest way to run a workflow on multiple objects and requires no workflow development, but it can only run workflows that take a single input parameter.
Creating a workflow that calls the Start workflows in a series or Start workflows in parallel workflows allows you to run on multiple objects workflows that take more than one input parameter. The calling workflow must create a properties array to pass the input parameters to the Start workflows in a series or Start workflows in parallel workflow. These workflows are only for use in other workflows. Do not run them directly.
Running a workflow in a For loop in a scripted element is faster than running a workflow in a loop of workflow elements, but it is less flexible and limits the potential for reuse. Most importantly, running a workflow in a scripted loop loses the checkpointing that Orchestrator performs when it starts each element in a workflow run. As a consequence, if the Orchestrator server stops while the scripted loop is running, when the server restarts, the workflow will resume at the beginning of the scripted element, repeating the whole loop. If the Orchestrator server stops while running a workflow with a loop of workflow elements, the workflow will resume at the specific element in the loop that was running when the server stopped.
For more information about the Batch workflows, see Using VMware vCenter Orchestrator Plug-Ins.
How to create a workflow that runs a workflow on an array of objects in a loop of workflow elements is demonstrated in Develop a Complex Workflow.
How to run a workflow in a scripted For loop is demonstrated in Workflow Scripting Examples.