This section provides an architecture overview and guidance on managing and scaling a VMware Horizon 7 environment on PowerEdge R7525 servers.
Figure 1 depicts the architecture of the validated solution, including the network, compute, management, and storage layers. This architecture aligns with the VMware Horizon block/pod design. A pod is made up of a group of interconnected Horizon Connection Servers that broker connections to desktops or published applications. A pod has multiple blocks to provide scalability, and a block is a collection of one or more vSphere clusters hosting pools of desktops or applications. Each block has a dedicated vCenter Server and composer servers (if linked clones are used).
The deployment option for this Dell EMC Ready Solutions for VDI solution supports all cloning techniques available from VMware: full, linked, and instant.
A vSphere cluster can have a maximum of 64 nodes and 8,000 virtual machines (VMs) per cluster (6,400 with vSAN). To expand beyond this limit, you can add clusters and balance the VMs and nodes across the new clusters.
The compute, management, and storage layers are converged into a block of PowerEdge servers, hosting VMware vSphere. The number of nodes that are supported for vSphere 6.7, which is 64, determines the recommended boundaries of an individual vSphere cluster.
Dell Technologies recommends that the VDI management infrastructure nodes be separated from the compute resources. In smaller environments, management and compute are in the same vSphere HA cluster. Optionally, the management node can also be used for VDI VMs with an expected reduction of 30 percent of host resources for these nodes only. The 30 percent accounts for management VM resource reservations and should be factored in when sizing. Compute hosts can be used interchangeably for Horizon Apps (hosted applications) and desktops, as required.
This reference architecture guide describes a single-site or single data center design. For multi-site or disaster recovery (DR) configurations, see the Horizon 7 Multi-Site Architecture.
VMware vSAN-based solutions provide flexibility as you scale, reducing the initial and future cost of ownership. Add additional physical and virtual servers to the server pools to scale horizontally (scaling out). Add virtual resources to the infrastructure to scale vertically (scaling up).
Each component of the solution architecture scales independently depending on the required number of supported users. You can add appliance nodes at any time to expand the vSAN Software Defined Storage (SDS) pool in a modular fashion. The scaling limit for vSAN is restricted by the limits of the hypervisor to 64 nodes per block.
The boundary for a Horizon block is the vCenter. The number of virtual machines a vCenter (and therefore a block) can host depends on the type of Horizon 7 VMs being used. The recommended limits for a Horizon block at the time of writing are:
For the latest sizing guidance, see VMware Configuration Maximums and VMware Horizon 7 sizing and limitations and recommendations.
This reference architecture guide uses instant clones, as shown in Figures 2 and 3.
VMware recommends a limit of 5,000 instant-clone VMs per block. With this limit in mind, 25 compute nodes with 200 knowledge user VMs per node would reach the maximum number of VMs for the block.
Figure 2 shows a 5,000-user Horizon block and pod supporting up to 5,000 knowledge user VMs. The VMware Horizon management infrastructure and knowledge user VMs are separated into separate vSphere clusters. Four management nodes are a suitable configuration to start with and can be scaled as appropriate.
A combined management and compute architecture could also be used, which would eliminate the need for a separate management cluster. In this configuration, each pod contains its own vCenter Server instance and VDI components.
The following figure shows a scale-out to a 20,000-user Horizon vSAN pod with 5,000-user blocks:
Dell Technologies recommends a validated disk configuration for general-purpose VDI. These configurations leave drive slots available for future vertical expansion and ensure that you protect your investment as new technology transforms your organization.
For more information about Horizon pod/block architecture and scaling, see the VMware Workspace ONE and VMware Horizon Reference Architecture.