CHAPTER 8 OPERATING SYSTEM FILE MANAGEMENT Learning Objectives

CHAPTER 8 OPERATING SYSTEM: FILE MANAGEMENT

Learning Objectives � � File management strategies and implementation. The capability of directory in order to succesfully manage files. Learning Objectives l Students knows the functionality of file management. l The importance of file management in all operating system.

File �Is a container for a collection of information. �Each file is a named collection of data stored in a device. File Protection Fundamental property files because it allows different people to store their information on a shared computer which info can kept confidential

File manager l To provides directories for organizing files. l To provides a spectrum of commands to read and write the content of a file l To set the files read/write position l To set and use the protection mechanism l To change the ownership l To list files in a directory and to remove a file

Supporting other storage abstractions �Structured sequential files - contain collection of logical records. �Indexed sequential files - each record contains an index field used to select it from file. �Database management system - DBMS are built on a fundamental storage manager. DBMS technology depends on the ability of the database administrator to choose the organization of records across and within files. �Multimedia document - multimedia files make demands on the storage systems that are similar to those of database.

Low- level files � Files keeps a data structure called as file descriptor (stored detailed information about).

Types of File Descriptor � � � � External name Current State Sharable Owner User Locks Protection settings Length Time of creation Time of last modification Time of last access Reference count Storage device details