A vCloud Director server group consists of one or more vCloud Director servers installed on Linux or deployments of the vCloud Director appliance. Each server in the group runs a collection of services called a vCloud Director cell. All cells share a single vCloud Director database and a transfer server storage, and connect to the vSphere and network resources.
To ensure vCloud Director high availability, you must install at least two vCloud Director cells in a server group. When you use a third-party load balancer, you can ensure an automatic failover without downtime.
You can connect a vCloud Director installation to multiple VMware vCenter Server® systems and the VMware ESXi™ hosts that they manage. For network services, vCloud Director can use NSX Data Center for vSphere associated with vCenter Server or you can register NSX-T Data Center with vCloud Director. Mixed NSX Data Center for vSphere and NSX-T Data Center are also supported.
A vCloud Director server group installed on Linux uses an external database.
A vCloud Director server group that consists of appliance deployments uses the embedded database in the first member of the server group. You can configure a vCloud Director database high availability by deploying two instances of the appliance as standby cells in the same server group. See Appliance Deployments and Database High Availability Configuration.
The vCloud Director installation and configuration process creates the cells, connects them to the shared database and transfer server storage, and creates the system administrator account. Then the system administrator establishes connections to the vCenter Server system, the ESXi hosts, and the NSX Manager or NSX-T Manager instances.
For information about adding vSphere and network resources, see the vCloud Director Service Provider Admin Portal Guide.