A storage system including a file migration server, a file migration
client, and an LDEV migration engine. The file migration client displays
on a management terminal a GUI for guiding a file migration. The file
migration server, upon receipt of a file migration command to migrate a
part of files stored in a source logical device to a destination logical
device, migrates all of the files stored in the source logical device to
the destination logical device without involving a change in directory
path.