Matsushita Electric Industrial Co., Ltd.

Hiroshi Taniyama

Yasunori Kawakami

The present invention relates to a method to handle dummy blocks without real data in a file management system. More specifically, block allocation means,is provided with a function of counting the number of dummy blocks without real data when there is a request to write new data at a file offset address one or more blocks away from the last file offset On in a specific file, and the unoccupied block management means,is additionally given a function of managing the number of unoccupied blocks subtracting the number of dummy blocks from the number of unoccupied blocks. That always leaves the number of unoccupied blocks with the number of the necessary blocks subtracted therefrom. The blocks necessary for later writing can be secured.

File management system and file management method capable of managing unoccupied blocks without the use of dummy data

The present invention relates to a file system using a disc memory storage and a method of managing the file system. Just like the ordinary server, a first block table Tb,with the offset number of the file to be written in matched with the block number Dij of the data block is provided, and the data stored in the memory is read out on the basis of the contents of the first block table Tb,On that file system, a second block registering means is provided which couples the block number allotted to the file to write and the offset number and, in case of consecutive block numbers, prepares a second block table Tb,in which the first block number of the consecutive block numbers is paired with the offset number. A second take-out means is also provided. When consecutive data are to be read out, the second block take-out means arithmetically processes, on the basis of the contents of the second block table Tb,the block numbers Dij to be read out and hands over the results to the data read-out means. That substantially reduces the access and processing time for read-out at the block table and makes the reading out of data highly efficient.

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Osaka-fu, Japan

Hiroshi Taniyama