On FlashArray models that use standard DFMs instead of DFMDs, which NVRAM bays are always...

This question addresses the distinction between the newer "Distributed NVRAM" architecture (DFMDs) and the "Dedicated NVRAM" architecture (using separate NVRAM modules in NVB slots).

If a FlashArray model is usingstandard DFMs(DirectFlash Modules that containonlyflash storage and no onboard NVRAM), the systemmustrely on dedicated NVRAM modules installed in the chassis to handle the write cache. As established in the hardware architecture for these generations (such as the //X R2/R3), the base requirement for system quorum and redundancy is a mirrored pair of NVRAM cards.

These cards arealways populated in NVB0 and NVB1. This ensures that even the smallest supported configuration has a redundant write buffer.

NVB0 and NVB1are the primary slots wired for this purpose on the midplane.

Populating non-contiguous slots like NVB0 and NVB3 or NVB0 and NVB2 would be an invalid configuration, likely preventing the array from booting or properly mirroring the write cache data between the modules.

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