Method, apparatus and system for remote file sharing

摘要

A technique is described to enable exclusive control on a file basis in a storage system while remote double recording is performed between storage controllers. A first shared-file controller has a table that stores control information used for excluding read and write to that file on a file basis. When the shared-file controller receives a data write request, it sets access to the file as exclusive, and then issues a command to a second shared file controller to set control information for that file. After data is written into a storage medium and mirrored to a second storage medium, a copy of the file management information is stored in memories of the shared-file controllers. The consistency of the file management information is maintained between the two file controllers by copying the file management information over the network.