Patent ID: 7680837

Claim:
A file management method in a log-structured file system for storing accesses to files that are sequentially performed by sequentially adding logs, comprising: previously dividing a storage area of a storage medium into a data area for storing a log including data of a file and a management area that can store management information related to the log stored in said data area for a plurality of entries; adding and storing said management information including a first number into said management area as a new entry without the management information being overwritten on a previous entry, the first number indicating the order of writing a log into said data area; and searching the newest entry in accordance with said first number and detecting a front log by using the management information of the entry; wherein said data area includes a plurality of small data areas and said management area includes a plurality of small management areas corresponding to said plurality of small data areas, and when a log is added and there is a need to use a new small data area for adding the log, the entry of said management information is stored in the small management area corresponding to the new small data area, wherein a header of said log includes a second number indicating the order of writing the log into said storage medium, and said detecting the front log includes finding the newest entry in accordance with the first number stored in each small management area in said management area, determining the small data area corresponding to the small management area of said newest entry as an object to be searched, and determining the newest log in accordance with second numbers of all logs in said small data area determined as the object to be searched and setting the log as the front log.