How does NetApp ensure data integrity during power loss?

• A. WAFL journaling, battery-backed cache (NVRAM), and consistent checkpointing protect data integrity.
• B. Only RAID configurations protect data.
• C. Power loss cannot be mitigated.
• D. Disabling caching preserves integrity.

Answer: (A)

NetApp protects data during power loss by combining three together-to-work mechanisms. WAFL journaling records metadata updates in a persistent log, so the filesystem can be brought back to a coherent state after a crash. The battery-backed cache (NVRAM) ensures that data already acknowledged to the host is durable even if power drops, by keeping those writes in nonvolatile memory until they can be safely flushed to disk. Consistent checkpointing periodically writes a stable view of in-memory state to disk, so the on-disk image remains aligned with what has been committed. Together, these prevent lost or corrupted writes when power is lost and allow a reliable recovery. RAID protects against disk failures, but it doesn’t address in-flight writes during a power outage, and disabling caching would not improve integrity and would hurt performance.