Patent ID: 8170985
Filing Date: 2012-05-01
Classification: G06F

Abstract:
1. A computer-implemented method of operating a primary file server and a secondary file server in a data network, said method comprising: the primary file server replacing a specified file in primary storage of the primary file server with a corresponding stub file in the primary storage when data of the specified file are migrated from the primary storage to secondary storage of the secondary file server, the corresponding stub file retaining attributes of the specified file including an indication of a location of the file data in the secondary storage; wherein the method further includes the secondary file server setting a retention period for the file data in the secondary storage, and the secondary file server retaining the file data in the secondary storage for the retention period; and wherein the primary file server sets at least one attribute of the corresponding stub file to indicate that the corresponding stub file is to be retained for the retention period, and the primary file server accesses said at least one attribute of the corresponding stub file to reject a request from a client or user to change the specified file prior to expiration of the retention period.