6.0.1

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.
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“Best Practices for
Networking,” on page 40.
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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,”
on page 18.
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vSphere HA supports both IPv4 and IPv6. See “Other vSphere HA Interoperability Issues,” on page 32
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.
Chapter 2 Creating and Using vSphere HA Clusters
VMware, Inc. 33