When performing a hardware non-disruptive upgrade (NDU) from a FlashArray//X70 R2 to a FlashArray//X70 R4, the Implementation Engineer must understand which components govern the compute upgrade and which house the actual customer data and state. A standard NDU kit for this specific inter-generational upgrade strictly includes the new //XR4 controllers and updated Power Supply Units (PSUs).

The //XR4 controllers utilize significantly more powerful Intel processors and PCIe Gen4 architecture compared to the older //XR2 models. Consequently, they draw considerably more power, necessitating a mandatory upgrade from the older //XR2 PSUs to the higher-wattage units included with the //XR4.

However, the existing NVRAM modules, chassis midplane, and DirectFlash Modules (capacity drives) currently serving data must absolutely remain in place. The legacy NVRAM holds the active, unwritten write cache for the array. If an engineer mistakenly uses the entire shipped //XR4 array (swapping NVRAM modules or migrating drives prematurely without a swing shelf procedure), they risk severe data corruption and an unrecoverable cache loss event. Thus, to safely complete the NDU while preserving data, only the controllers and the power supplies should be harvested from the newly shipped chassis.