The physical layer in ROBO SDDC contains the compute, storage, and network resources in your data center.

The compute, storage and network resources are organized in workload domains. The physical layer also includes the physical network infrastructure, and storage setup.

Figure 1. Physical Configuration of the ROBO SDDC

Workload Domains

At the physical layer, workload domains can include different combinations of servers, and network equipment which can be set up with varying levels of hardware redundancy and varying quality of components. Workload domains are connected to a network core that distributes data between them. The workload domain is not defined by any hard physical properties. It is a standard unit of connected elements within the SDDC.

Workload domain is a logical boundary of functionality, managed by a single vCenter Server. While each workload domain usually spans one rack, it is possible to aggregate multiple workload domains into a single rack in smaller setups. For both small and large setups, homogeneity and easy replication are important.


This VMware Validated Design uses the following types of clusters:

Consolidated Cluster

The consolidated cluster resides in the management workload domain and runs the following services:

  • Virtual machines to manage the SDDC such as vCenter Server, NSX Manager, vRealize Automation, vRealize Log Insight and vRealize Operations Manager.
  • Required NSX services to enable north-south routing between the SDDC and the external network, and East-West routing inside the SDDC.
  • Virtual machines running business applications that support varying Service Level Agreements (SLAs).


This VMware Validated Design uses a Layer 3 network architecture.
  • A Top of Rack (ToR) switch is typically located inside a rack and provides network access to the servers inside that rack.
  • An inter-rack switch at the aggregation layer provides connectivity between racks. Links between inter-rack switches are typically not required. If a link failure between an inter-rack switch and a ToR switch occurs, the routing protocol ensures that no traffic is sent to the inter-rack switch that has lost connectivity.

Regions, Hubs and ROBO Sites

A hub is the centralized provisioning and monitoring components of the SDDC. A hub can be dedicated to ROBO sites according to the number of remote office connections required or be a part of the VMware Validated Design for Software-Defined Data Center. In either case, the hub has the capability for failover between regions in the event of a disaster.
Each region is a separate SDDC instance and can contain one or more availability zones. This VMware Validated Design uses two example regions in the hub: one in San Francisco (SFO) and the other in Los Angeles (LAX).
Table 1. Regions in VMware Validated Design for Remote Office and Branch Office
Region Disaster Recovery Role Region-Specific Domain Name
Region A Protected sfo01.rainpole.local
Region B Recovery lax01.rainpole.local
Availability Zone
Represent the fault domain of the SDDC. Multiple availability zones can provide continuous availability of an SDDC. By default, this VMware Validated Design supports one availability zone in each region in the hub. Alternatively, you can implement an SDDC that has two availability zones in Region A. See Multiple Availability Zones in Standard SDDC.
ROBO site
A ROBO site is a location that you use to support specific services such as manufacturing, hospitals, or call centers. These locations require minimal workload deployment and have hardware located in space constrained rooms.
Table 2. Sites in VMware Validated Design for Remote Office and Branch Office
Site Identifier Description
NYC01 New York City, NY, USA based Remote Office and Branch Office


This VMware Validated Design provides guidance about the storage of the management components. The design uses two storage technologies:

Primary Storage
vSAN storage is the default storage type for the SDDC management components. All design, deployment and operational guidance are performed on vSAN.

The storage devices on vSAN ready servers provide the storage infrastructure. Because this VMware Validated Design uses vSAN in hybrid mode, each rack server must have minimum one SSD and two HDD devices that form a disk group with capacity.

Secondary Storage
NFS storage is the secondary storage for the SDDC management components. It provides space for archiving log data and application templates.