NetApp Certified Storage Architect (NCSA) — Question 1

With a system cache block size of 32K, how much cache space per I/O is "lost" if incoming I/Os are all 48K writes? (Choose the best answer.)

Answer options

• A. 24K
• B. 8K
• C. 0 – no space is lost
• D. 4K
• E. 16K

Correct answer: D

Explanation

The correct answer is D because when a 48K write is performed, it occupies two cache blocks of 32K each, resulting in 16K of the second block being wasted. The first 32K block is fully utilized, but only 4K of the second block is used, leading to 4K of lost space. The other options do not accurately reflect the calculations based on the system cache block size and the size of the writes.