An administrator is tasked with vertically scaling a vSAN ESA deployment.

When vertically scaling a vSAN ESA cluster, adding the same model and capacity drives helps preserve a balanced and predictable cluster design. vSAN works best when hosts use uniform storage configurations. The guidance states that unbalanced host configurations reduce predictability of storage performance because vSAN does not store the same number of components on each host, can introduce different maintenance procedures, and can reduce performance on hosts with smaller or different device types. In ESA, each storage device contributes both capacity and performance through the storage pool model, so mixing device models, endurance classes, or capacities can create uneven consumption and inconsistent backend behavior. Using the same drive model and capacity across hosts improves capacity symmetry, keeps maintenance and replacement procedures consistent, and makes performance planning more predictable. The cache-drive option is incorrect because ESA is single-tier and does not use separate cache and capacity tiers. Equal cache and capacity tiers apply to OSA-style thinking, not ESA. vSAN File Services being configured does not drive the requirement to use identical drives. Reference topics: vSAN ESA Storage Pool Design, Balanced and Unbalanced Cluster Configuration, ESA Device Performance, Vertical Scaling.