6.0

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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 the vSphere Availability publication for
more information on VM and application monitoring.
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vSphere HA supports both IPv4 and IPv6. See the vSphere Availability publication for more information
on vSphere HA interoperability.
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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 (vVol) datastores, when vSphere HA is enabled a configuration
vVol is created on each vVol 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 vVol datastore.
Creating and Configuring a vSphere HA Cluster
vSphere HA operates in the context of a cluster of ESXi (or legacy ESX) hosts. You must create a cluster,
populate it with hosts, and configure vSphere HA settings before failover protection can be established.
When you create a vSphere HA cluster, you must configure a number of settings that determine how the
feature works. Before you do this, identify your cluster's nodes. These nodes are the ESXi hosts that will
provide the resources to support virtual machines and that vSphere HA will use for failover protection. You
should then determine how those nodes are to be connected to one another and to the shared storage where
your virtual machine data resides. After that networking architecture is in place, you can add the hosts to
the cluster and finish configuring vSphere HA.
You can enable and configure vSphere HA before you add host nodes to the cluster. However, until the
hosts are added, your cluster is not fully operational and some of the cluster settings are unavailable. For
example, the Specify a Failover Host admission control policy is unavailable until there is a host that can be
designated as the failover host.
NOTE The Virtual Machine Startup and Shutdown (automatic startup) feature is disabled for all virtual
machines residing on hosts that are in (or moved into) a vSphere HA cluster. Automatic startup is not
supported when used with vSphere HA.
Create a vSphere HA Cluster in the vSphere Client
To enable your cluster for vSphere HA, first create an empty cluster. After you have planned the resources
and networking architecture of your cluster, you can use the vSphere Client to add hosts to the cluster and
specify the cluster's vSphere HA settings.
Open a vSphere Client connection to a to vCenter Server using an account with cluster administrator
permissions.
vSphere Administration with the vSphere Client
384 VMware, Inc.