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Table Of Contents
Creating and Using vSphere HA
Clusters 26
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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“vSphere HA Checklist,” on page 383
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“Creating and Configuring a vSphere HA Cluster,” on page 384
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“Customize an Individual Virtual Machine in the vSphere Client,” on page 389
vSphere HA Checklist
The vSphere HA checklist contains requirements that you must be aware of before creating and using a
vSphere HA cluster.
Review this list before you set up a vSphere HA cluster. For more information, follow the appropriate cross
reference.
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All hosts must be licensed for vSphere HA.
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A cluster must contain at least two hosts.
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All hosts must be configured with static IP addresses. If you are using DHCP, you must ensure that the
address for each host persists across reboots.
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All hosts must have at least one management network in common. The best practice is to have at least
two management networks in common. You should use the VMkernel network with the Management
traffic checkbox enabled. The networks must be accessible to each other and vCenter Server and the
hosts must be accessible to each other on the management networks. See the vSphere Availability
publication for best practices.
VMware, Inc.
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