IT320OPERATING SYSTEM CONCEPTS

Unit 7: File ManagementMay 2012

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Upcoming Topics

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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

Unit 7: Reading & Assignments

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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)

Unit 7: Discussion Question

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Directory Structure – Linux vs Windowso 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/

Unit 7: Assignment

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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.

Unit 7: File Management

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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

Unit 7: Grading Rubric

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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.

Chapter 12 – File Management8

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File Management Question 1 What is file management?

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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.

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File Management Question 3 What are the basic requirements needed

for a file management system on any operating system?

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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

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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

2nd Level – Logical I/O Enables users and applications to access records

3rd Level – Basic I/0 Supervisor Responsible for all file I/O initiation and termination

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File System Architecture

4th 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?

5th Level – Device Drivers Communicate directly with peripheral devices or

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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

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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

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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.

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File Sharing

Access rights include None Knowledge Execution Reading Appending Updating Changing Protection Deletion

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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

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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

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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?

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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)

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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

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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

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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?

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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

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Preview – Final Project27

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Final Project

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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

Final Project

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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)

Processes & Threads 15 pts Deadlock (avoidance, prevention, detection) 15 pts I/O for chosen OS 10 pts Scheduling 10 pts Data Protection (RAID, backups) 15 pts File Management 10 pts Security Techniques & Defenses 10 pts Security Threats (viruses, bots, worms) 15 pts

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Final Project – Grading Rubric

Any Questions?

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Pam Van HookEmail: pvanhook@kaplan.edu