Before you set up vCenter HA, ensure that you have sufficient memory, CPU, and datastore resources, and ensure that you are using versions of vCenter Server and ESXi that support vCenter HA.

Your environment must meet the following requirements.

Table 1. vCenter HA Requirements
Component Requirements
  • ESXi 5.5 or later is required.
  • Three hosts are strongly recommended. Each vCenter HA node can then run on a different host for better protection.
  • Using VMware DRS to protect the set of hosts is recommended. In that case, a minimum of three ESXi hosts is required.
Management vCenter Server (if used) Your environment can include a management vCenter Server system, or you can set up your vCenter Server Appliance to manage the ESXi host on which it runs (self-managed vCenter Server)
  • vCenter Server 5.5 or later is required.
vCenter Server Appliance
  • vCenter Server 6.5 is required.
  • Deployment size Small (4 CPU and 16GB RAM) or bigger is required to meet the RTO. Do not use Tiny in production environments.
  • vCenter HA is supported and tested with VMFS, NFS, and vSAN datastores.
  • Ensure you have enough disk space to collect and store support bundles for all three nodes on the Active node. See Collecting Support Bundles for a vCenter HA Node.
Network connectivity
  • vCenter HA network latency between Active, Passive, and Witness nodes must be less than 10 ms.
  • The vCenter HA network must be on a different subnet than the management network.
Licensing required for vCenter HA
  • vCenter HA requires a single vCenter Server license.
  • vCenter HA requires a Standard license.
Note: When trying to configure vCenter HA on an SDRS cluster, an error message is displayed. This option is not supported.