EXTENT BASE FILE SYSTEM HAVING MULTIPURPOSE INDIRECT SPECIFICATION OR MULTIPLE VOLUMES

摘要

PROBLEM TO BE SOLVED: To obtain a more flexible method for extending an existent file by allowing each (i) nodes to have multiple lines and storing extent indicating data blocks in some of the lines. SOLUTION: A physical structure includes directories 61 and 62 and (i) nodes 63 and 64. The directory 61 converts abstract file names and directory names to the physical addresses of the (i) nodes 63 and 64 and directory 62. The (i) nodes 63 and 64 stores a list of extents 65 to 66 wherein successive file segments are mapped to strings of physical data blocks 80 to 82, 84 to 85, and 92 to 94. The physical directories 61 and 62 and (i) nodes 63 and 64 are stored in a global cache memory. Copies of relative physical directories 61 and 62 and/or (i) nodes 63 and 64 are also locally stored in volatile memories of a processor and a driver.