To notify the possibility of failure in a storage device in advance, in a management technology for storing data in a storage means.

A list of files whose sizes are increased can be notified to managers without failure by recording the list of files increased in size when updating the file, and notifying the list periodically to the managers. The occurrence of an abnormal state in a log can be notified at an early stage by comparing the list of the file increased in size with a DB owned by a vendor, and notifying the list of files whose sizes are increased from normal operating time. A conventional method for monitoring the files increased in size has a drawback that although a system administrator probes the list of files increased in size, such as a log file in advance from a manual etc., and the increase in size of the file is managed, it cannot monitor an omission of a file at the time of probing it from the manual, a file not described in the manual, and a file of a user created program, and herewith, the above problem is resolved.