In one embodiment, a new storage system is connected to an old storage system
destined for replacement. Prior to starting online data migration, remote copy
configuration information from the old storage system is migrated to the new storage
system. The aforementioned allows either the new storage system or the old storage
system, depending on configuration, to maintain an operational remote copy function
with another storage system during the online data migration. The old and new storage
systems can be primary storage systems located in a local site. The old and new
storage systems can also be secondary storage systems located in a site remotely
located from a local site.