Which vSAN feature requires an all-flash cluster?

Within the VMware vSAN framework embedded inside the Dell VxRail infrastructure, certain storage efficiency features are structurally bound to the underlying media types. Specifically, deduplication and compression (Choice D) is a core space-saving technology that fundamentally requires an all-flash cluster deployment when utilizing the Original Storage Architecture (OSA). In an all-flash configuration, vSAN executes deduplication and compression at the block level during the destaging phase, as data transitions from the caching tier to the capacity tier.

Because these hashing and block-matching algorithms impose intensive mathematical processing overhead and demand rapid, random read/write lookups to maintain throughput without introducing system latency, VMware restricts this capability entirely to solid-state drives across both storage tiers. Attempting to run deduplication and compression on a hybrid node configuration utilizing spinning magnetic disks for capacity is structurally barred because traditional HDDs cannot support the high-performance random I/O required for metadata manipulation. In contrast, security and orchestration features such as data-at-rest encryption, data-in-transit encryption, and storage policy-based management (SPBM) are software-defined storage abstractions that operate uniformly across both hybrid and all-flash cluster environments.