5.8.5

Table Of Contents
Create Capacity Scenarios for Virtual Machines With New Profiles
Virtual machine scenarios assess the consequences of adding a new virtual machine to a cluster or host
without applying actual changes to your virtual environment.
To help you make configuration selections for virtual machines, the right pane of the What-If Scenario
wizard contains population information that shows the total virtual machine use of the selected object and
representative virtual machine data. vCenter Operations Manager calculates virtual machine data by
partitioning the range of capacity for CPU, memory, and disk dimensions into thirds, assigning the virtual
machines to bins based on configuration, and creating a profile for each bin where the capacity of the profile
is the maximum configuration of the virtual machines in the bin and the use of the profile is the average
usage of the virtual machines in the bin. The value of the virtual machines assigned to the profile and the
use is the average of the virtual machines assigned to the profile. The right pane includes information on the
smallest and largest hosts.
For information about relevant CPU and memory maximums, see the VMware vSphere documentation.
NOTE The What-if Scenario wizard is accessible only if you select a host or a cluster in the inventory pane.
Prerequisites
In vCenter Operations Manager, verify that the Summary tab under the Planning tab is open.
Procedure
1 Select the destination object in the inventory pane.
The destination object is a cluster or host where you locate the new virtual machines if you implement
your scenario.
2 Click the New what-if scenario link.
The What-If Scenario wizard opens.
3 Select a view for the scenario and click Next.
This step is not available if you opened the What-if Scenario wizard from the Views tab.
4 On the Change Type page, select Virtual machines and click Next.
5 Select Add virtual machines by specifying profile of new virtual machines and click Next.
6 Set the virtual machine count and the configuration for the virtual machine.
Option Description
vCPU Configuration
Number of virtual CPU cores that a target virtual machine will have,
followed by the target processor core speed, in GHz or MHz.
vCPU Utilization
Expected average CPU use for this virtual machine.
vCPU Reservation
Required minimum of CPU resources that the virtual machine must have.
vCPU Limit
Amount of maximum CPU resources that the virtual machine can use.
Memory Reservation
Required minimum of memory for this virtual machine.
Memory Limit
Amount of maximum memory that the destination virtual machine can
have.
Virtual Disk Type
Thin or Thick disk configuration.
You might apply thin disk provisioning when you start with only the
necessary partition and plan to grow it over time.
Chapter 5 Assessing Risk and Efficiency in vCenter Operations Manager
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