A storage where one NAS server makes snapshot management information including global paths of snapshots based on snapshot identifiers and global paths of file systems corresponding to the snapshots, so that global paths of both the file systems and 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 other NAS servers of the snapshot management information; memory in each of the NAS servers stores the snapshot management information; the snapshot management information includes the snapshot identifier, local path and 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.