The following example illustrates how you can change resource allocation settings to improve virtual machine performance.

Assume that on an ESX/ESXi host, you have created two new virtual machines—one each for your QA (VM-QA) and Marketing (VM-Marketing) departments.

Single Host with Two Virtual Machines
In this example, a single host has two virtual machines.

In the following example, assume that VM-QA is memory intensive and accordingly you want to change the resource allocation settings for the two virtual machines to:

Specify that, when system memory is overcommitted, VM-QA can use twice as much memory and CPU as the Marketing virtual machine. Set the memory shares and CPU shares for VM-QA to High and for VM-Marketing set them to Normal.

Ensure that the Marketing virtual machine has a certain amount of guaranteed CPU resources. You can do so using a reservation setting.

1

Start the vSphere Client and connect to a vCenter Server.

2

Right-click VM-QA, the virtual machine for which you want to change shares, and select Edit Settings.

3

Select the Resources tab, and in the CPU panel, select High from the Shares drop-down menu.

4

In the Memory panel, select High from the Shares drop-down menu.

5

Click OK.

6

Right-click the marketing virtual machine (VM-Marketing) and select Edit Settings.

7

In the CPU panel, change the Reservation value to the desired number.

8

Click OK.

If you select the cluster’s Resource Allocation tab and click CPU, you should see that shares for VM-QA are twice that of the other virtual machine. Also, because the virtual machines have not been powered on, the Reservation Used fields have not changed.