Patent ID: 8145873

Claim:
A data management method for a network storage system, said network storage system including a storage network, a cluster of storage servers that provides data storage services to application servers connecting to said storage network, and storage space corresponding to each storage server, wherein said data stored in said storage servers includes raw data that are accessed by the application servers and metadata stored in the own local storage space of each of the storage servers, said method comprising: setting a core manager in each storage server, said core manager: separating logically a location of the metadata from each of said storage servers, centralizing logically the own local storage spaces of all the storage servers to form logically a common storage space and to make logically the storage servers become storage managers which no longer logically have the own local storage space and for storing its corresponding metadata, centralizing logically the metadata of all the storage servers in the common storage space, allocating a storage location of the metadata in said common storage space, and managing the corresponding relationship between the metadata and said storage managers; wherein said common storage space is divided into partitions, said storage managers and said partitions having one to one and/or one to more mapping relationship; wherein said core manager comprises: an allocation controller that distributes the metadata into the partitions of said common storage space, a mapping controller that manages the mapping relationship between the partitions of said common storage space and said storage managers by a mapping table, and a partition controller that manages the partitions of said common storage space; said method, further comprising an operation of adding more storage managers including: (1) a new storage manager connecting to the network storage system; (2) the network storage system finding the new storage manager; (3) the mapping controller adjusting the mapping table, and adding the mapping relationship between the new storage manager and some partitions; (4) the partition controller locking a queue of the accessing requests queue to the partitions needed to be transferred to the new storage manager; (5) the partition controller unloading the partitions needed to be transferred from the storage manager that currently manages the partitions; (6) the partition controller loading the partitions in the new storage manager; (7) unlocking the queue of accessing requests to the partitions.