The unified resources of a VxRail create a virtual infrastructure that is defined and managed as a vSphere cluster under a single instance of vCenter. A decision must be made to use the VxRail-managed vCenter Server, which is deployed in the cluster as part of the initial initialization process, or a customer-managed vCenter server, which is external to the cluster. During the VxRail initialization process which creates the final product, you must select whether to deploy the embedded VxRail-managed vCenter Server on the cluster or deploy the cluster on an external customer-managed vCenter server. Once the initialization process is complete, migrating to a new vCenter single point of management requires professional services assistance, and is difficult to change.

Dell recommends that you consider all the ramifications during this planning and preparation phase and decide on the single point of management option that will work most effectively for your organization.

The following should be considered for selecting the VxRail vCenter server:

• A vCenter Standard license is included with VxRail cluster with vSAN, and does not require a separate license. This license cannot be transferred to another vCenter instance.
• VxRail Lifecycle Management supports the upgrade of the VxRail vCenter server. Upgrading a customer-managed vCenter using VxRail Lifecycle Management is not supported.
• DNS services are required for VxRail. With the VxRail vCenter option, you have the choice of using the internal DNS supported within the VxRail cluster, or leveraging external DNS in your data center. The internal DNS option will only support naming services on which the VxRail cluster is deployed. This option cannot support naming services outside of that cluster.

For a customer-managed vCenter, the following items should be considered:

• The vCenter Standard license included with VxRail cannot be transferred to a vCenter instance outside of the VxRail cluster.
• Multiple VxRail clusters can be configured on a single customer-managed vCenter server, limiting the points of management.
• With the customer-managed vCenter, external DNS must be configured to support the VxRail cluster.
• Ensuring version compatibility of the customer-managed vCenter with VxRail is the responsibility of the customer.
• With the customer-managed vCenter, you have the option of configuring the virtual distributed switches yourself to support the VxRail cluster or have VxRail deploy a virtual distributed switch and perform the configuration instead. This option is advantageous if you want better control and manageability of the virtual networking in your data center and consolidate the number of virtual distributed switches in your vCenter instance.
• If you are planning to deploy one or more dynamic VxRail clusters where the primary storage resource is going to be a remote vSAN datastore, a customer-managed vCenter is preferable. All clusters participating in sharing and receiving vSAN datastore resources must reside in a common vCenter instance.   

Note: The option to use the internal DNS or to deploy the VxRail cluster against a preconfigured virtual distributed switch requires VxRail version of 7.0.010 or later.

For more details on the planning steps for a customer-managed vCenter, see the VMware vCenter Server on Dell VxRail Planning Guide.