RAID20 Has the Natural Advantage of Supporting a Smart Tier

Multiple Choice

RAID2.0 has the natural advantage of supporting a smart tier, to accelerate the performance of hot data. Which of the following descriptions about the smart tier performance is correct?

A) When smart LUNs act as backup media, smart tier's performance improvement on this LUN is not obvious.
B) During the running of the business, the extent size can be adjusted by the size of the hotspot area to obtain better performance.
C) Literacy ratio in the 1:9 scenario, enabling the smart tier has greatly improved the performance of the business.
D) Smart tier has no effect on host performance during hot data migration.