6.7

Table Of Contents
Figure 21. Single Host with Two Virtual Machines
VM-QA
host
VM-Marketing
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:
n
Specify that, when system memory is overcommitted, VM-QA can use twice as much CPU and
memory resources as the Marketing virtual machine. Set the CPU shares and memory shares for
VM-QA to High and for VM-Marketing set them to Normal.
n
Ensure that the Marketing virtual machine has a certain amount of guaranteed CPU resources. You
can do so using a reservation setting.
Procedure
1 Browse to the virtual machines in the vSphere Client.
2 Right-click VM-QA, the virtual machine for which you want to change shares, and select Edit
Settings.
3 Under Virtual Hardware, expand CPU and select High from the Shares drop-down menu.
4 Under Virtual Hardware, expand Memory and 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 Under Virtual Hardware, expand CPU and change the Reservation value to the desired number.
8 Click OK.
Admission Control
When you power on a virtual machine, the system checks the amount of CPU and memory resources that
have not yet been reserved. Based on the available unreserved resources, the system determines
whether it can guarantee the reservation for which the virtual machine is configured (if any). This process
is called admission control.
If enough unreserved CPU and memory are available, or if there is no reservation, the virtual machine is
powered on. Otherwise, an Insufficient Resources warning appears.
Note In addition to the user-specified memory reservation, for each virtual machine there is also an
amount of overhead memory. This extra memory commitment is included in the admission control
calculation.
vSphere Resource Management
VMware, Inc. 15