Management Domain to Rack Mapping in VMware Cloud Foundation
VMware Cloud Foundation
The functionality in an SDDC is distributed across multiple workload domains and vSphere clusters. A workload domain, whether it is a management domain or virtual infrastructure workload domain, is a logical abstraction of compute, storage, and network cloud capacity and consists of one or more clusters. Each cluster can exist vertically in a single rack or be spanned horizontally across multiple racks. You determine the total number of racks for each cluster type according to your scalability needs.
The relationship between workload domains and data center racks in
VMware Cloud Foundation
is not one-to-one. While a workload domain is an atomic unit of repeatable building blocks, a rack is a unit of size. Because workload domains can have different sizes, you map workload domains to data center racks according to your requirements and physical infrastructure constraints.When using a Layer 3 network fabric, the clusters in the management domain cannot span racks. Management appliances and virtual machines rely on VLAN-backed networks. The physical network configuration terminates Layer 2 networks in each rack at the top-of-rack (ToR) switch. Therefore, you cannot migrate a virtual machine to a different rack because the IP subnet is available only in the rack where the virtual machine is currently running. However, you can map each management cluster to a single rack.
Management Domain to Rack Configuration | Description |
|---|---|
Management domain in one rack | The management domain can occupy exactly one rack, whether it consists of a single or multiple clusters. |
Management domain across multiple racks | To span multiple racks, the network fabric must support stretched Layer 2 networks between these racks. Otherwise, map each cluster in the management domain to a single rack. |
Management domain with multiple availability zones, each zone in one
rack | To span multiple availability zones, the network
fabric must support stretched Layer 2 networks between the availability
zones. |
Management domain with multiple availability zones, each zone
spanning multiple racks | To span multiple availability zones, the network
fabric must support stretched Layer 2 networks between the availability
zones. Otherwise, map each cluster in the management domain to a single
rack. |
Management Domain in One Rack
Management Domain Spanning Multiple Racks
Management Domain with Multiple Availability Zones, Each Zone in One Rack
Management Domain with Multiple Availability Zones, Each Zone Spanning Multiple Racks
In an environment with multiple VMware Cloud Foundation instances, for example, you can have two availability zones in the first instance only. Each zone spans over the default management cluster on a single rack server.