Which of the following descriptions about Huawei RAID 2.0+ technology is correct? (Multiple choice)
A . The hard disk types of each storage layer in the hard disk domain are the same
B . The hard disk space is divided into fixed-size blocks
C . The user can set the "RAID strategy" for each storage tier in the storage pool.
D . Grain is the smallest granularity of data migration and the basic unit that constitutes Thin LUN
Answer: ABC