When 500 bytes are written to RAID 5 with a 512-byte sector size, data verification is not required.

• A. True
• B. False
• C. Not applicable
• D. Depends on controller

Answer: (B)

RAID 5 protects against disk failure using parity, but that parity only helps recover lost data—not automatically guarantee that every written byte was stored exactly as intended. When you write 500 bytes with a 512-byte sector size, the operation still targets sector-sized blocks and typically triggers a read-modify-write to update the data and the parity across the stripe. If something goes wrong during that write (power loss, caching issue, or a disk error), you can end up with data corruption that parity alone won’t instantly detect. Data verification (or a post-write check/ scrub) helps ensure the actual stored data matches what you wrote, catching latent errors. So saying data verification isn’t required isn’t correct; verification is relevant to maintain data integrity even in RAID 5 with 512-byte sectors.