A VMware Cloud Director server group consists of one or more VMware Cloud Director servers installed on Linux or deployments of the VMware Cloud Director appliance. Each server in the group runs a collection of services called a VMware Cloud Director cell. All cells share a single VMware Cloud Director database and a transfer server storage, and connect to the vSphere and network resources.

Important: Mixed VMware Cloud Director installations on Linux and VMware Cloud Director appliance deployments in one server group are unsupported.

To ensure VMware Cloud Director high availability, you must install at least two VMware Cloud 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 VMware Cloud Director installation to multiple VMware vCenter Server® systems and the VMware ESXi™ hosts that they manage. For network services, VMware Cloud Director can use NSX Data Center for vSphere associated with vCenter Server or you can register NSX with VMware Cloud Director. Mixed NSX Data Center for vSphere and NSX are also supported.

Figure 1. VMware Cloud Director Linux Installation Architecture Diagram
The cluster contains four VMware Cloud Director servers, each of which runs a VMware Cloud Director cell.
Figure 2. VMware Cloud Director Appliance Architecture Diagram
The cluster contains a primary appliance and two standby appliances that form an HA embedded database cluster.

A VMware Cloud Director server group installed on Linux uses an external database.

A VMware Cloud Director server group that consists of appliance deployments uses the embedded database in the first member of the server group. You can configure a VMware Cloud Director database high availability by deploying two instances of the appliance as standby cells in the same server group. See VMware Cloud Director Appliance Deployments and Database High Availability Configuration.

Figure 3. VMware Cloud Director Appliances Comprising an Embedded Database High Availability Cluster

The VMware Cloud 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-V Manager or NSX Manager instances.

For information about adding vSphere and network resources, see the VMware Cloud Director Service Provider Admin Guide.