A secured file system with optimum disk access latency

摘要

File systems manage permanent storage and form an integral part of all operating systems. At the highest level a file system is a way to organize, store, retrieve and manage information on a permanent storage medium such as a disk. File system is the higher level abstraction of the complex data storage method in the storage medium. The main aspects of our proposed file system are 1. faster data access, i.e. reduced seek time and latency time. 2. secured file access. 3. less disk space fragmentation and , 4. large sized file storage. The file system that we have proposed in this paper provides both faster access to data as well as secured file access, i.e. this file system implements the disk block addressing in an encrypted manner and makes unauthorized data retrieval using low level disk access extremely difficult. Moreover disk block allocation for a file is maintained dynamically using a dynamic index structure which guarantees the faster data access and storage of files larger than 4GB. Moreover the proposed file system also reduces the addressing overhead for each file. It has been noticed that this proposed file s ystem shows better performance in terms of addressing overhead compared to inode file structure. This file system also requires less disk block access to read a file than FAT file system. In the worst case when FAT file system requires 2n block access to read a file of n blocks, the proposed file system requires n + (n/126+log_(127) n/126) blocks access.