[goodpoint]

Compare your solution with having 4 SBCs, with 1 NVME each, at different locations. The network client would handle replication and checksumming.

The total cost might be similar but you have increased reliability over SBC/controller/uplink failure.

Of course there are tradeoffs on performance and ease of management...

[Godel_unicode]

You think that building 4 systems in 4 locations is likely to have a similar cost to one system at one location? For small systems, the fixed costs are a significant portion of the overall system cost.

This is doubly true for physical or self-hosted systems.