Patent ID: 8375002

Claim:
A storage system comprising: a storage device for storing a file; a plurality of file systems for managing the file; and a plurality of NAS servers that control access from a client to the file systems via a global namespace formed by grouping local namespaces for the plurality of file systems; wherein each NAS server includes a memory to store global namespace management information including global paths of the file systems; one NAS server of the NAS servers accepts a request to obtain snapshots of the file systems from outside of the storage system; the one NAS server instructs itself and the other NAS server to obtain snapshots of the file systems; the one NAS server and the other NAS servers obtain the snapshots of the file systems, and inform the one NAS server of snapshot identifiers and of local paths of the snapshots; the one NAS server makes snapshot management information including global paths of the snapshots based on each of the snapshot identifiers and each of the global paths of file systems corresponding to the snapshots, so that both the global paths of the file systems and the global paths of the snapshots are configured on the same global namespace simultaneously, with a directory configuration of the snapshots being the same in configuration layout as a directory configuration of the file systems; the one NAS server informs the other NAS servers of the snapshot management information; the memory in each of the NAS servers stores the snapshot management information; the snapshot management information includes the snapshot identifier, the local path and the global path for each of snapshots obtained by each NAS server at each point in time; and the computer obtains the snapshot management information from at least one of the NAS servers and displays at least a part of the snapshot management information.