To complete the Non-Disruptive Upgrade (NDU) from an //X70R2 to an //X90R3 using a fully shipped array, the Implementation Engineer must extract and use the Controllers and NVRAM modules.
Stateless Architecture: The FlashArray upgrade philosophy allows the chassis and data drives (Data Packs) to remain in place while the compute (controllers) and cache (NVRAM) are swapped.
Component Compatibility:
Controllers: The X90R3 controllers provide the upgraded CPU/performance required.
NVRAM: The NVRAM modules (located in the chassis front or rear slots depending on generation, but logically paired with controller performance) often differ between generations (R2 vs. R3) and performance tiers (70 vs. 90). The X70R2 NVRAM modules are typically not compatible with X90R3 controllers. Therefore, the engineer must swap the NVRAM modules along with the controllers to ensure the write cache is recognized.
Power Supplies: Both the X70R2 and X90R3 utilize the same high-capacity 1600W Power Supply Units. Unless the existing PSUs are faulty, they do not technically need to be swapped for the system to function, making "Controller and NVRAM" the precise minimum requirement for the logic upgrade.