If a disk domain has multiple disk types, the storage pools in that disk domain...

A disk domain is a collection of physical disks of the same type and speed. If a disk domain has multiple disk types, it is not necessary that the storage pools within that disk domain have multiple disk types as well. Storage pools are a collection of physical disks within a disk domain that are grouped together to provide storage capacity. The storage pools can be created with different RAID levels and disk types, so it is possible to have a disk domain with multiple disk types and still have storage pools with only one disk type. It depends on how the administrator wants to configure the storage pool and how the storage is used.