Your Cloud Foundation system's management domain and deployed workload domains are logical units that carve up the compute, network, and storage resources of the entire system. The logical units are groups of ESXi hosts managed by vCenter Server instances with specific characteristics for redundancy and VMware SDDC best practices.
The management domain and workload domains include these VMware capabilities by default:
VMware vSphere® High Availability (HA)
In a VMware virtual environment, this feature supports distributed availability services for a group of ESXi hosts, to provide rapid recovery from outages and cost-effective high availability for applications running in virtual machines. When DRS is configured and one of the hosts in the group becomes unavailable, all virtual machines on that host are immediately restarted on another host in the group. For more information about vSphere HA, see the vSphere Availability documentation at https://docs.vmware.com/en/VMware-vSphere/.
VMware vSphere® Distributed Resource Scheduler™ (DRS)
In a VMware virtual environment, this feature dynamically allocates and balances computing capacity across a group of hardware resources aggregated into logical resource pools. DRS continuously monitors uses across resource pools and allocates available resources among the virtual machines based on predefined rules that reflect business needs and changing priorities. When a virtual machine experiences an increased load, vSANDRS automatically allocates additional resources by redistributing virtual machines among the physical servers in the resource pool. For more information about DRS, see the vSphere Resource Management documentation at https://docs.vmware.com/en/VMware-vSphere/.
In a VMware virtual environment, this component aggregates local and direct-attached storage disks in a group of ESXi hosts to create a storage pool shared across all hosts in that group. For more information about vSAN, see the VMware vSAN documentation at https://docs.vmware.com/en/VMware-vSAN/.
By default, the Cloud Foundation system has a management domain dedicated to infrastructure and management tasks . The management domain is automatically provisioned when you perform bring-up on a rack and includes the hosts you selected during bring-up. The Cloud Foundation software stack is deployed on the management domain. When you add racks to your system, the management domain automatically covers the additional racks. If you run out of resources, you can expand the management domain by selecting eligible hosts on any rack in your system.
If you have deployed Cloud Foundation on seven or more hosts, the deployment is based on the standard architecture. On this architecture model, you can deploy two pre-packaged environments named Virtual Infrastructure (VI) and Virtual Desktop Infrastructure (VDI). To deploy one of these environments, you use a workflow to carve a pool of capacity out of the available capacity, and the SDDC Manager provisions the environment, called the workload domain, using that carved-out pool of capacity. The software automatically determines the required amount of capacity to carve out based on your input for:
Resources (CPU, memory, and storage)
If you have deployed Cloud Foundation six or fewer hosts, the deployment is based on the consolidated architecture. Since you do not have enough hosts to create a workload domain, you can utilize part of the capacity on the management domain by creating workload VMs and adding them to the management domain.
The SDDC Manager software provides this policy-driven approach to capacity deployment. Based on the levels you specify, the necessary hardware resources are reserved out of the available physical infrastructure. Then using those reserved hardware resources, the workflow deploys the appropriate software stack, applies storage policies, and automatically provisions and configures the virtual environment with the software required for the VMware SDDC stack and the elements required for the selected workload type. The workflow automatically:
Deploys the vSphere environment and configures it for vSAN and enables vSphere HA and DRS, if required by your selected availability policy
Configures the virtual networks, including the appropriate NSX for vSphere elements, as appropriate for the specified workload domain configuration
Integrates the workload domain's resources with the appropriate pieces in the Cloud Foundation software stack
The result is a workload-ready SDDC environment.
Each Cloud Foundation instance is one SSO domain to which all vCenter Servers are joined. The maximum number of supported workload domains and vCenter Servers per Cloud Foundation instance depends on the vSphere version in the management cluster. For more information, see the Configuration Maximums vSphere document.
All of the instances for the VDI environment's servers — the vCenter Server, View Connection Server, View Composer, and so on — are created within a management domain.
The Dashboard page displays high-level information about the management and workload domains that are deployed in your system. From the Dashboard page, you can drill-down to details on each management and workload domain by using the View Details button.
You cannot create a workload domain or make any changes to a workload domain while an update is in progress.
If you intend to migrate VMs between vCenter instances on potentially different hardware, you should enable EVC on the affected clusters to avoid issues. See Enable EVC on an Existing Cluster in the vSphere product documentation.