6.0.1

Table Of Contents
If you select the cluster’s Resource Reservation 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.
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.
When the vSphere DPM feature is enabled, hosts might be placed in standby mode (that is, powered off) to
reduce power consumption. The unreserved resources provided by these hosts are considered available for
admission control. If a virtual machine cannot be powered on without these resources, a recommendation to
power on sufficient standby hosts is made.
Chapter 2 Configuring Resource Allocation Settings
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