For increased availability, VMware recommends deploying the NSX Edge in a high availability (HA) configuration. In this configuration, the two NSX Edge appliances must be placed on different datastores for increased redundancy. The primary appliance will be active and host all NSX Edge services, while the secondary appliance will be in standby mode. A heartbeat is maintained between the appliances over an internal interface. For a complete description of the failover process for NSX Edge appliances deployed in HA mode, see the VMware NSX 6.2 Administration Guide.