Patent US 9,727,430

Services are promptly resumed at the time of a failure recovery in an information processing system. Before a first server system 3a resumes service during the failure recovery, a second server system 3b sends the first server system 3a directory images of directories of a highest-level tier to a predetermined lower-level tier out of data of files stored in a second storage apparatus 10b, and the first server system 3a restores the directory images in a first storage apparatus 10a. When the request is transmitted from the first server system 3a, the second server system 3b reads an additional directory image from the second storage apparatus 10b and transmits the additional directory image to the first server system 3a. If a re-stubbing occurrence frequency is equal to or higher than a predetermined threshold, the second server system 3b suppresses transmission of directory images to the first server system 3a.