A database system includes a center server and local servers. The center
server includes a replication requesting unit, a data consolidating unit
including a center DB freeze requesting unit and a center DB freeze
release requesting unit, a replication source managing table and a data
consolidation completion notifying unit. Each of the local servers
includes a local DB freeze requesting unit, a remote volume split
requesting unit, a remote volume split completion notifying unit and a
local DB freeze release requesting unit. The center server permits
replications of local DB's in local storage subsystems to be created in
the center storage subsystem and accesses shadow images of the
replications to give a consolidated access to the plurality of local
DB's.