FILE MANAGING DEVICE

PROBLEM TO BE SOLVED: To prevent the performance reduction of a filing system for video having necessity to perform high-speed real-time access, and to efficiently execute recovery processing in case of system fault. SOLUTION: A file operating request from a user is accepted by a program 100 and corresponding to operating request contents, a program 101 is activated. At the time of file open, prepare and close, a program 113 is activated, an updated open file list (update list) and an updated file managing information table (update table) are written in a disk and at the time of file read and file write, the program 100 is activated but the update list and update table are not written in this disk. At the time of recovery operation in case of fault, the program 113 is activated, a list is read out of the disk and only the table of file having a file number described in this list is read out by activating the program 113.