1. IT320 OPERATING SYSTEM CONCEPTS Unit 7: File Management May 2012 Kaplan University 1

2. Upcoming Topics Kaplan University 2  Unit 7: File Management  Unit 8: Computer Security Risks & Data Protection  Unit 9: Distributing Computing and Networking  Unit 10: Final Project  Due Tuesday, May 29 by 11:59 pm ET

3. Unit 7: Reading & Assignments Kaplan University 3  Textbook Reading  Chapter 12 – File Management  Start with chapter summary first!  Web Articles Reading  1 discussion question  3 page essay based on File Management (due Tuesday)

4. Unit 7: Discussion Question Kaplan University 4  Directory Structure – Linux vs Windows o In addition to your book reading about the Linux file system, take a look at this article about the Linux file system anatomy. Compare Linux to the way Windows deals with files and compare the two directory structures. o http://www.ibm.com/developerworks/linux/library/l-linux- filesystem/

5. Unit 7: Assignment Kaplan University 5  Select one operating system you are familiar with. Write a one-page summary that lists and explains the utilities provided by the operating system to manage the file system.  How often should these utilities be executed?  How is file security implemented?  Write a one-page summary comparing FAT/FAT32 and NTFS file systems in a Windows operating system.  What are the benefits of each?  Why would one file system used over the other?  Write a one-page summary examining the various file systems available to Linux including the directory structure and compare them to the Windows file system. Be sure to list the similarities and differences.

6. Unit 7: File Management Kaplan University 6  Your paper should include at least 3 pages of content (including required content, intro & conclusion)  Note that your paper will be longer than 3 pages as it will have a title page and a reference page in addition to the actual content pages required.  Be sure to include an introduction and conclusion (5 pts each)  Use APA format

7. Unit 7: Grading Rubric Kaplan University 7  15 pts – Examine the file and directory structure for Windows  15 pts – Examine the file and directory structure for Linux  10 pts – Compare Linux file system and directory structure to Windows  10 pts – List the utilities to the OS of your choice to manage the file system.

8. Chapter 12 – File Management 8 Kaplan University

9. File Management Question 1  What is file management? Kaplan University 9

10. File Management Question 2  Give me an example of how you use organize information (not on the computer).  Examples might include:  Recipes  DVDs  Bills & Paperwork  Paper files at work  Explain how you keep this information organized. Kaplan University 10

11. File Management Question 3  What are the basic requirements needed for a file management system on any operating system? Kaplan University 11

12. File Management System  File Management System  Set of system software that provides services to users and applications in the user the files  Minimum set of requirements: Users should be able to create, delete, read, write and modify files Users may have controlled access to other users’ files Users may control types of access to files Users should be able to move data between files Users should be able to back up and recover files Users should be able access files by name rather than numbers Kaplan University 12

13. File System Architecture  Figure 12.1 (Textbook – p. 555)  Top Level – Access method  Standard interface between applications and the files systems and device that hold data  2 nd Level – Logical I/O  Enables users and applications to access records  3 rd Level – Basic I/0 Supervisor  Responsible for all file I/O initiation and termination Kaplan University 13

14. File System Architecture  4 th Level – Basic File System  Also known as Physical I/O Level  Primary interface with the environment outisde the computer system  Deals with blocks of data exchanged on secondary storage device  Can you name an example of secondary storage?  5 th Level – Device Drivers  Communicate directly with peripheral devices or their controllers or channels Kaplan University 14

15. File Organization & Access  Important Criteria:  Short access time  Ease of update  Economy of storage  Simple maintenance  Reliability  File Organization Types  Pile  Sequential File  Indexed Sequential File  Indexed File  Direct (hashed) file  See pp. 558-562 15 Kaplan University

16. File Directory  The Directory contains information about the files, including attributes, location, & ownership.  Figure 12.2 (p. 563) show information elements  Basic Information file name, file type, file organization  Address Information volume, starting address, size used  Access Control Information owner, access information, permitted actions  Usage Information date created, indentity, last read, last modified 16

17. File Management Question 4  Right click on a file on your computer.  View “Properties” and then “Security”  Name as least 3 types of permissions associated with that file. Kaplan University 17

18. File Sharing  Access rights include  None  Knowledge  Execution  Reading  Appending  Updating  Changing Protection  Deletion Kaplan University 18

19. Windows File System  New Technology File System (NTFS)  Flexible and powerful file system build on simple file system model  Recoverability  Security  Large disks and large files (more efficient than FAT)  Multiple data streams  Journaling  Compression & Encryption Kaplan University 19

20. NTFS Volume & File Structure  Disk Storage Concepts  Sector Smallest physical storage unit on disk, typically 512 bytes  Cluster One or more contiguous sectors (next to each other)  Volume A logical partition on a disk, consisting of one or more clusters used by a file system to allocate space Kaplan University 20

21. File Allocation Table (FAT)  File Allocation Table (FAT)  Stores position of each file in a directory tree  Directories are not files  Need a mapping function to dynamically construct files corresponding to the directories  What issues can you see with FAT vs NTFS? Kaplan University 21

22. Linux Virtual File System  Virtual File System (VFS)  Single, uniform file system interface to user processes  Assumes files are objects in computer’s storage memory  Files have symbolic names to allow unique ID  Diagram of Linux File system Figure 12.17 (p. 588) Kaplan University 22

23. Comparing Windows & Linux  Nice comparison chart (p. 592)  Windows File System  NTFS  Implemented as a device driver (can be layered)  Depends on I/O System & Cache manager  Directories, files, & file system metadata are all represented as files by NTFS  Relies on unified caching by the CACHE manager Kaplan University 23

24. Comparing Windows & Linux  Linux File System  Most common are Ext2, Ext3, JFS (Journaling file system)  Implemented using the Virtual File System (VFS) technique (created by Sun Microsystems)  File Systems are plug-ins for VFS model  Used a page cache, keeps copies of recently used pages in memory  VFS treats directory entries and file metadata separate from actual files Kaplan University 24

25. Operating System Utilities  Definition – “system software designed to help analyze, configure, optimize, and maintain the computer” (Wikipedia, 2010).  Different than application software  Typically highly specialized  http://en.wikipedia.org/wiki/Utility_software  Can you name 2 examples of operating system utilities? Kaplan University 25

26. OS Utility Categories  Disk Storage  Defragmenters  Disk Checkers  Disk Cleaners  Disk Partitions  Backup  Disk Compression  File Managers  Archive  System Profilers  Anti-virus  Cryptographic  Registry Cleaners  Network Utilities 26 Kaplan University

27. Preview – Final Project 27 Kaplan University

28. Final Project Kaplan University 28  Due Tuesday, May 29  No late assignments accepted!!!  Final Project is worth 100 points  Write a 5 – 10 page essay explaining how a mainstream modern (Linux or Windows) Operating System is designed to integrate all components of the operating system.  At least 3 outside references  Include topics on the next page

29. Final Project Kaplan University 29  The following list of topics is a starting point for your essay. You may include other topics if you feel they are important.  Processes and threads  Memory management  Scheduling (Including deadlock prevention)  File Management  Input and Output devices  Security issues (Discuss current malware threats & prevention techniques)  Data protection (RAID & Clusters)

30.  Processes & Threads15 pts  Deadlock (avoidance, prevention, detection)15 pts  I/O for chosen OS10 pts  Scheduling10 pts  Data Protection (RAID, backups)15 pts  File Management10 pts  Security Techniques & Defenses10 pts  Security Threats (viruses, bots, worms)15 pts Kaplan University 30 Final Project – Grading Rubric

31. Any Questions? Kaplan University 31  Pam Van Hook Email: pvanhook@kaplan.edu