Which component provides nonvolatile storage for the RAID system's primary cache?

Which component provides nonvolatile storage for the RAID system's primary cache?

• A. RAM
• B. NAND flash memory
• C. HDD cache
• D. Multiport memory controller

Answer: (D)

The thing being tested is how RAID controllers keep cached data safe across power events. Even though RAM is fast, it’s volatile and would lose the cached writes if power is lost. To provide true nonvolatile storage for the primary cache, the RAID controller uses a memory controller that manages memory banks including nonvolatile cache resources (often implemented as NVRAM or flash-backed cache). The multiport memory controller is the component responsible for coordinating access to these memory resources across multiple channels and ensuring that cached write data can be stored nonvolatily and recovered after power-up. That’s why this component is the best answer: it enables the nonvolatile caching capability the RAID system relies on, whereas RAM would be volatile, HDD cache is on the drives, and NAND flash memory is the storage technology itself, not the controller that offers the nonvolatile cache interface.

The thing being tested is how RAID controllers keep cached data safe across power events. Even though RAM is fast, it’s volatile and would lose the cached writes if power is lost. To provide true nonvolatile storage for the primary cache, the RAID controller uses a memory controller that manages memory banks including nonvolatile cache resources (often implemented as NVRAM or flash-backed cache). The multiport memory controller is the component responsible for coordinating access to these memory resources across multiple channels and ensuring that cached write data can be stored nonvolatily and recovered after power-up. That’s why this component is the best answer: it enables the nonvolatile caching capability the RAID system relies on, whereas RAM would be volatile, HDD cache is on the drives, and NAND flash memory is the storage technology itself, not the controller that offers the nonvolatile cache interface.