Following on from vCenter CapacityIQ - Part 2 - Dashboard, Views and Reports we will review What-If Scenarios.

These scenarios are used to model changes in virtual resources specifically hosts and virtual machines.

You can create scenarios based on the following criteria:

Hosts

• Adding a host
• Changing host capacity
• Removing a host 

Virtual Machines 

• Adding a virtual machine based on custom settings
• Adding a virtual machine based on an existing virtual machine profile
• Removing virtual machines

1. Creating a What-If Scenario

To create a What-If Scenario, Select the cluster object and Click "What-If Scenario".

2. What-If Scenario Type

The scenario wizard will start.

In this example we will model adding virtual machines.

Select "Virtual Machines" and Click Next. 

3. Choose the scenario

We will create a scenario by adding 5 virtual machines to the cluster based on a specification we provide.

Select "Add virtual machines by specifying profile of new virtual machines".

Click Next. 

4. Configuration 

Specify the amount of virtual machines that will be added.

Specify the configuration of the virtual machines:

• Number of vCPUs
• Clock speed of vCPUs
• CPU utilisation
• Amount of memory
• Memory utilisation

Click Next.

5. View (Trend / Summary)

Select how you would like to view the scenario results.

• Trend (Graphical)
• Summary (Comparison table)

Click Next. 

6. Review scenario

Check the scenario settings are correct and Click Finish to see the results view. 

7. Review the What-If scenario results

The results view will be displayed in a comparison table.

Because we modelled adding 5 VMs were most intrested in the "Remaining" part of the table.

This shows us based on our current host capacity we will be short of 6.09 GHz or CPU and 5.44GB of memory.

So we will be unable to add these 5 vitual machines without resource contention.

With these results, you can export the information to PDF and discuss with management you need additional memory or hosts to acheive this requirement.

CapacityIQ is very easy to use and for a 1.0 product is quite useful. While there are several additional features I would like to see, such as custom views/reports, scheduled reports, automated emails and alerts about capacity, i'm sure they will come with time as Capacity IQ evolves.

vCenter CapacityIQ - Part 1 - Installing

vCenter CapacityIQ - Part 2 - Dashboard, Views and Reports

vCenter CapacityIQ - Part 3 - What-If Scenario