Update Description

Pool-specific acceleration: This function is implemented based on multiple Global Cache clusters with a maximum of 128 nodes each. You need to select a Global Cache cluster for acceleration pools. For a non-acceleration pool, you do not need to select a Global Cache cluster. Instead, use the native Ceph.

Fault domain: The fault domain for a placement group (PG) with three copies can be a node or rack. If the fault domain is a rack, all nodes in the rack have only one PG copy.