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VMware vSphere 5.0 Evaluation Guide –
Volume One
Admission Control
Figure 16.
Host Monitoring Status and Admission Control Attributes
In the cluster settings dialog box, select vSphere HA from the navigation tree on the left. This allows you to edit
the Host Monitoring Status and Admission Control attributes.
Host monitoring enables VMware HA to take action if a host fails to send heartbeats over the management
network. During maintenance operations on the management network, it is possible that the hosts will not be
able to send heartbeats. When this occurs, you should unselect this option to prevent VMware HA from believing
the hosts are isolated.
Admission control is used to ensure that adequate resources within the cluster are available to facilitate failover if
needed. It also serves to ensure that the virtual machine reservations are respected. Three options are available
to specify the desired admission control policy. These include the following:
• Host failures
This option attempts to reserve enough capacity within the cluster to provide for the failure of any host within
the cluster.
• Percentage
As with the host failures option, this also attempts to reserve enough capacity within the cluster. However, this
option allows you to specify a percentage of CPU and memory that you want reserved.