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Table Of Contents
Creating and Using vSphere HA
Clusters 2
vSphere HA clusters enable a collection of ESXi hosts to work together so that, as a group, they provide
higher levels of availability for virtual machines than each ESXi host can provide individually. When you
plan the creation and usage of a new vSphere HA cluster, the options you select affect the way that
cluster responds to failures of hosts or virtual machines.
Before you create a vSphere HA cluster, you should know how vSphere HA identifies host failures and
isolation and how it responds to these situations. You also should know how admission control works so
that you can choose the policy that fits your failover needs. After you establish a cluster, you can
customize its behavior with advanced options and optimize its performance by following recommended
best practices.
Note You might get an error message when you try to use vSphere HA. For information about error
messages related to vSphere HA, see the VMware knowledge base article at
http://kb.vmware.com/kb/1033634.
This chapter includes the following topics:
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How vSphere HA Works
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vSphere HA Admission Control
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vSphere HA Interoperability
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Creating a vSphere HA Cluster
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Configuring vSphere Availability Settings
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Best Practices for VMware vSphere
®
High Availability Clusters
How vSphere HA Works
vSphere HA provides high availability for virtual machines by pooling the virtual machines and the hosts
they reside on into a cluster. Hosts in the cluster are monitored and in the event of a failure, the virtual
machines on a failed host are restarted on alternate hosts.
VMware, Inc.
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