The SDDC differentiates between different types of clusters including management clusters, compute clusters, edge clusters, and shared edge and compute clusters.
Figure 1. Clusters in a Single Availability Zone in the SDDC


A management cluster (4 ESXi hosts) and an Edge and Compute cluster (4 ESXi hosts) are in one rack with two ToR switches.

Figure 2. Clusters in Two Availability Zones in the SDDC


Stretched management cluster (4 ESXi hosts) and Stretched Edge and Compute cluster (4 ESXi hosts) are in Availability Zone 1 in one rack with two ToR switches. Stretched management cluster (4 ESXi hosts) and Stretched Edge and Compute cluster (4 ESXi hosts) are in Availability Zone 2 in one rack with two ToR switches. Both racks are in Region A. In Region B a management cluster (4 ESXi hosts) and an Edge and Compute cluster (4 ESXi hosts) are in one rack with two ToR switches.

Management Cluster

The management cluster lives in the management workload domain and runs the virtual machines that manage the SDDC. These virtual machines host vCenter Server, vSphere Update Manager, NSX Manager, NSX Controller, vRealize Operations Manager, vRealize Automation, vRealize Log Insight, and other management components. Because the management cluster contains critical infrastructure, consider implementing a basic level of hardware redundancy for this cluster.

Management cluster components must not have tenant-specific addressing.

Shared Edge and Compute Cluster

The shared edge and compute cluster is the first cluster in the virtual infrastructure workload domain and hosts the tenant virtual machines (sometimes referred to as workloads or payloads). This shared cluster also runs the required NSX services to enable North-South routing between the SDDC tenant virtual machines and the external network, and east-west routing inside the SDDC. As the SDDC expands, you can add more compute-only clusters to support a mix of different types of workloads for different types of Service Level Agreements (SLAs).

Compute Cluster

Compute clusters live in a virtual infrastructure workload domain and host the SDDC tenant workloads. An SDDC can contain different types of compute clusters and provide separate compute pools for different types of SLAs.

External Storage

External storage provides non-vSAN storage using NFS, iSCSI or Fiber Channel. Different types of storage can provide different levels of SLA, ranging from just a bunch of disks (JBODs) using IDE drives with minimal to no redundancy, to fully redundant enterprise-class storage arrays.