5.8.5

Table Of Contents
Option Description
Virtual Disk Linked Clone
Shared space that uses linked clones.
Linked clones involve delta disks that reference a master disk rather than a
full copy of the entire virtual hard disk. For thick disks with linked clones,
vCenter Operations Manager calculates linked clone capacity as one
master copy that uses 100 percent of the specified disk size and the
remaining copies use 10 percent delta disks. For thin disks with linked
clones, vCenter Operations Manager uses the same calculation but the disk
size multiplied by the use percentage defines the master copy size.
Virtual Disk Configuration
Disk size.
Virtual Disk Utilization
Expected average disk use for the virtual machine.
The use percentage applies only to thin disks.
vCenter Operations Manager does not require you to specify the disk I/O and network I/O use of the
new virtual machines, and instead uses the average disk I/O and network I/O use across virtual
machines in the host or cluster as an estimation of the new virtual machine use.
7 Click Next when your configuration selections are complete.
8 On the Ready to Complete page, check the parameters of your what-if scenario and click Finish to view
the outcomes.
vCenter Operations Manager applies the scenario to the view you selected and shows current capacity
compared to the expected capacity if you add the virtual machines to the target object.
Create Capacity Scenarios for Virtual Machines With Existing Profiles
You can create a scenario that uses profiles of existing virtual machines as models to simulate adding one or
more new virtual machines to a host or a cluster.
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.
VMware vCenter Operations Manager Getting Started Guide
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