The computer system is composed of an old storage apparatus, a new storage
apparatus, management computer, data network and management network.
Management computer gathers logs at the old storage apparatus. When data
is moved from the old storage to the new storage, destination volume in
the new storage apparatus is allocated and concatenated using the
gathered log information and a mapping table. The system and apparatus
simplifies migration processes from ordinary storage apparatus to the new
storage device, which may include HDDs and FLASH memory units. The system
takes into account the differences in performance characteristics of HDDs
and FLASH memories, achieving improver performance of the overall storage
system.