6.7

Table Of Contents
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To ensure that any virtual machine can run on any host in the cluster, all hosts must have access to
the same virtual machine networks and datastores. Similarly, virtual machines must be located on
shared, not local, storage otherwise they cannot be failed over in the case of a host failure.
Note vSphere HA uses datastore heartbeating to distinguish between partitioned, isolated, and
failed hosts. So if some datastores are more reliable in your environment, configure vSphere HA to
give preference to them.
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For VM Monitoring to work, VMware tools must be installed. See VM and Application Monitoring.
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vSphere HA supports both IPv4 and IPv6. See Other vSphere HA Interoperability Issues for
considerations when using IPv6.
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For VM Component Protection to work, hosts must have the All Paths Down (APD) Timeout feature
enabled.
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To use VM Component Protection, clusters must contain ESXi 6.0 hosts or later.
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Only vSphere HA clusters that contain ESXi 6.0 or later hosts can be used to enable VMCP. Clusters
that contain hosts from an earlier release cannot enable VMCP, and such hosts cannot be added to a
VMCP-enabled cluster.
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If your cluster uses Virtual Volume datastores, when vSphere HA is enabled a configuration Virtual
Volume is created on each datastore by vCenter Server. In these containers, vSphere HA stores the
files it uses to protect virtual machines. vSphere HA does not function correctly if you delete these
containers. Only one container is created per Virtual Volume datastore.
Create a vSphere HA Cluster in the vSphere Client
To enable your cluster for vSphere HA, you must first create an empty cluster. After you plan the
resources and networking architecture of your cluster, use the vSphere Client to add hosts to the cluster
and specify the cluster's vSphere HA settings.
A vSphere HA-enabled cluster is a prerequisite for vSphere Fault Tolerance.
Prerequisites
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Verify that all virtual machines and their configuration files reside on shared storage.
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Verify that the hosts are configured to access the shared storage so that you can power on the virtual
machines by using different hosts in the cluster.
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Verify that hosts are configured to have access to the virtual machine network.
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Verify that you are using redundant management network connections for vSphere HA. For
information about setting up network redundancy, see Best Practices for Networking.
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Verify that you have configured hosts with at least two datastores to provide redundancy for vSphere
HA datastore heartbeating.
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Connect vSphere Client to vCenter Server by using an account with cluster administrator
permissions.
vSphere Availability
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