Using the what-if tool, you can plan for an increase or decrease in workload or capacity requirements in your virtual infrastructure. To evaluate the demand and supply for capacity on your system objects, and to assess the potential risk to your current capacity, you can create scenarios for adding and removing workloads. You can also determine how much capacity you require to make a migration work. You can run one scenario or group scenarios and run them cumulatively.
Why Create a Scenario
A scenario is a detailed estimation of the resources you must have available in your environment to incorporate upcoming changes. You define scenarios that can potentially add resources to actual data centers. vRealize Operations models the scenario and calculates whether your desired workload can fit in the targeted data center. You can save multiple scenarios for comparison or review.
Where You Find What-If Analysis
In the left menu, select Capacity under Plan. The Overview tab of the What-If Analysis page has four panes. Each pane lets you run What-If scenarios to optimize capacity based on workload, physical infrastructure HCI nodes, or migration to the cloud.
How What-If Analysis Works
You can run What-If scenarios to see how much capacity will remain after you add or remove VMs or hosts and add hyperconverged infrastructure (HCI) nodes. Migration planning shows you the capacity and cost information after migrating to cloud based infrastructure.
Scenarios that you save for later are displayed as a list in the Saved Scenarios tab. You can run, edit or delete the saved scenarios. You can select more than one compatible scenarios and run them together. For example, you can create a scenario to remove hosts using the Physical Infrastructure Planning pane, because your organization has hardware that will soon become obsolete. You can create another scenario to add hosts to your physical infrastructure to account for new hardware that will replace the obsolete ones. You can run both these scenarios together to see the capacity after removing old hardware and adding new hardware.
You can only combine scenarios that pertain to the same object. Use the filters in the Saved Scenarios tab to narrow down the list based on scenario name, type, data center, or cluster.
The Scenario Summary page displays the results of running one or more saved scenarios. To add or remove saved scenarios and run them again cumulatively, click Edit in the Scenario Summary page .
