Abstract: In a file system capable of reserving a storage area, disk fragments can be prevented and an insufficient file system area is hard to occur. A response time of writing a small size file can be shortened. When a file is written, a file size is compared with a plurality of preset threshold values and reservation is executed at a reservation size corresponding to the file size. If the reservation is failed due to an insufficient file system capacity, the reservation is again executed at an actual I/O size to effectively use the file system area. If the file size does not reach the preset smallest threshold value, the reservation is again executed at the actual I/O size and the reservation release process for the file equal to or smaller than the smallest threshold value is skipped.

Abstract: A reasoning method capable of easily describing a model of diagnosis, a diagnosis method based on the reasoning method and a fault diagnosis system for performing efficiently faulty component diagnosis. Basic knowledge of a domain for which a knowledge base is used, expert's heuristic knowledge and meta-level knowledge for determining a scheme of use of the basic knowledge and the heuristic knowledge are provided. Fault diagnosis is performed for an objective of interest by executing a combination of reasoning based on the basic knowledge and reasoning based on the heuristic knowledge, in accordance with the meta-level knowledge.

Abstract: In method and apparatus for restarting, after occurrence of a fault, an online processing system based on a computer employing a virtual storage system comprised of a main storage and a first auxiliary storage, a second auxiliary storage is additionally provided, occupied/unoccupied status of slots on the first auxiliary storage is managed by an auxiliary storage management table of the main storage, data present in the main storage immediately after IPL is saved in a first area of the second auxiliary storage, data present in the main storage at the time of the occurrence of the fault is saved in a second area, and data occuring in the auxiliary storage management table at the time of the occurrence of the fault is saved in a third area.