Patent ID: 7587436
Filing Date: 2009-09-08
Classification: G06F,Y10S

Abstract:
1. A storage system, comprising: a plurality of servers being coupled to a client computer, integrating a plurality of file systems which are managed by each of the plurality of servers, and providing a global name space (GNS) for the client computer to access any one of a plurality of files by sending an access request to any of the plurality of servers; and a disk subsystem being coupled to the plurality of servers and storing the plurality of files, wherein each of the plurality of servers is configured to comprise GNS management information including a plurality of relationships each relating a local path, to which a file system of the plurality of file systems is locally mounted in a local name space managed by a respective one of the plurality of servers, to a connecting point on the GNS, wherein each of the plurality of servers is configured to comprise migration point management information including a plurality of relationships each relating a migration point, which is a local path of a directory below a root directory managed by one of the plurality of servers and is served as a base point of dividing a portion from a file system of the plurality of file systems, to a file system identifier (ID) uniquely identified throughout the storage system, wherein, when the client computer sends a name resolve request of a first file identified by a first path of the GNS to first one of the plurality of servers, the first one of the plurality of servers is configured to acquire a first local path corresponding to the first path of the GNS based on the GNS management information, if the first local path is managed by the first one of the plurality of servers, and is further configured to transfer the name resolve request to a second one of the plurality of servers based on the GNS management information, if the first local path is managed by the second one of the plurality of servers, wherein, if the first one of the plurality of servers acquires the first local path, the first one of the plurality of servers is configured to acquire a first migration point that is above and closest to the first local path, is further configured to acquire a first file system ID of the first migration point based on the migration point management information, and is further configured to send to the client computer a file handle including the first file system ID and a first file identifier (ID) associated with the first file, wherein, if the second one of the plurality of servers acquires the first local path after receiving the name resolve request transferred from the first one of the plurality of servers, the second one of the plurality of servers is configured to acquire the first migration point, is further configured to acquire the first file system ID of the first migration point based on the migration point management information, and is further configured to send to the client computer the file handle including the first file system ID and the first file ID associated with the first file, and wherein, when the first one of the plurality of servers receives a migration request designating the first migration point to be migrated, the first one of the plurality of servers is configured to divide a portion from a first file system of the plurality of file systems, if the first one of the plurality of servers acquires the first local path and the first migration point is not a topmost directory of the first file system of the plurality of file systems, and is further configured to migrate the portion of the first file system to the second one of the plurality of servers after dividing the portion from the first file system.