The present invention provides techniques for managing data flow over a
plurality of connections between primary and remote storage devices. In a
representative example embodiment, when the primary storage system copies
data to the secondary storage system, it chooses one of a plurality of
networks connecting it to the secondary storage system, depending upon a
users' policy. Since networks have different characteristics, in terms
of, for example, performance, security, reliability, and costs, the user
can specify which network(s) are used under various circumstances, i.e.,
daytime operation, nighttime operation, normal operation, emergency, and
so forth. The storage systems comprise a mapping of volumes and ports.
When performing copy operations, the primary storage system finds a
volume storing the data, and available ports by accessing the mapping.
The mappings are based upon policies that are input by a user.