VxRail scale-out clusters start with as few as two nodes and can grow in one-node increments up to 64 nodes, providing performance and capacity to meet a wide range of use cases. New systems can be added non-disruptively and different models can be mixed within a VxRail cluster. Flexible storage options also allow a node to start with a few drives and add drives as capacity requirements grow, as shown in the following figure. Single node upgrades and drive scalability protect an optimized initial investment by allowing customers to start with what they need and expand the VxRail cluster by adding nodes and/or drives to increase performance and capacity as needed. Consult the Dell representative for assistance.

Figure 20.    VxRail scale on demand

A few basic rules regarding scaling are worth considering for planning:

Balance

• At initial deployment, the first three nodes in a cluster must have identical configuration – 2-node vSAN clusters require both nodes to be identical.
• All nodes must be running the same version of software.
• Cannot mix hybrid, and all-flash or all-NVMe nodes in the same cluster.
• 1GbE, 10GbE, and 25GbE base networking cannot be mixed in the same cluster.
• 1GbE must be hybrid and single processor node type.
• For G Series, all nodes in a chassis must be identical.
• All nodes in a cluster must use the same processor vendor, either Intel or AMD. A cluster may have different generations of processors from a vendor. This is a VMware restriction.

Flexibility

• Systems in a cluster can be different models or series after initial deployment
• A cluster can have a varied number of drives, CPU, memory, and model types.
• A cluster can have between 2-64, but only a max of 8 if 1GbE networking is used.
• For G Series, a chassis can be partially populated.

Upgradeable options

With VxRail, nodes can upgrade or add memory, NIC cards, cache drives, and capacity drives. GPU can be upgraded or added in the supported node types. It is not possible to upgrade from all-flash to all-NVMe.