Which of the Following Is True About the Principle of Huawei

Which of the following is true about the principle of Huawei Oceanstor V3 smart cache: (multiple choice)

A) When an IO arrives at the storage system, in order to avoid affecting the write performance, the data in the smart cache will not be any changes due to the IO
B) When reading the data in the missing smart cache, the smart cache pool directly forwards the read IO request to the HDD
C) If OceanStor V3 is shared between services A and B, the same custom smart cache partition can be used
D) The system generates a default smart cache partition for each controller by default