When designing and deploying a Dell VxRail cluster utilizing VMware vSAN 8 Express Storage Architecture (ESA), network throughput requirements are significantly higher than traditional Original Storage Architecture (OSA) deployments. The minimum required network speed for all traffic-bearing network interfaces assigned to the vSAN ESA data path is strictly defined as 25 Gbps. This mandatory speed profile is dictated by the architectural modifications inherent to ESA, which replaces the traditional two-tier disk group model with a unified, high-performance single-tier storage pool built exclusively on NVMe-based flash media.
Because data paths are optimized for parallel disk accesses, activities such as inter-node replication, active write mirroring, and data erasure coding over the network domain can easily overwhelm lower-bandwidth infrastructure. Running vSAN ESA over 1 Gbps or 10 Gbps uplinks is structurally prohibited because network-induced latency would bottleneck the NVMe performance capabilities and trigger cluster instability during host failovers or data rebuild cycles. Therefore, 25 Gbps represents the absolute minimum speed requirement to pass pre-deployment hardware validation gates.
References: Dell VxRail Deploy Study Guide; vSAN ESA Hardware Prerequisites; Network Topology and Performance Requirements.