IT320 OPERATING SYSTEM CONCEPTS Unit 7: File Management July 2011 Kaplan University 1.

IT320OPERATING SYSTEM CONCEPTS

Unit 7: File ManagementJuly 2011

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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, July 26 by 11:59 ET

Unit 7 Overview

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Readings Discussion Questions Review Unit 7 Assignment Lecture on File Management Preview of Final Project

Unit 7: Reading & Assignments

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Textbook Reading Chapter 12 – File Management Start with chapter summary first!

Web Articles Reading 2 Discussion Questions 3 page essay based on File Management

(due Tuesday)

Unit 7: Discussion Questions

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DQ1: NTFS vs FATo Visit the two links below to learn more about NTFS and

FAT. Feel free to review other publications to learn about the two file systems, including their highlights, applications, strengths, and weaknesses.

• DQ2: 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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1. 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?

2. 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?

3. Write a one-page summary comparing the Unix, Linux, and Windows file systems.

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 to include an introduction and conclusion (5 pts each)

Use APA format

Unit 7: Grading Rubric

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Chapter 12 – File Management9

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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

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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 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 Project24

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Final Project

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Due Tuesday, July 26 No late assignments accepted!!! Final Project is worth 200 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)

Paper Length (5 pages), APA Style 10 pts Content of paper shows understanding 20 pts Introduction & Conclusion included 10 pts Processes & Threads 20 pts Deadlock (avoidance, prevention, detection)

20 pts I/O for chosen OS 20 pts Scheduling20 pts Data Protection (RAID, backups) 20 pts File Management 20 pts Security Techniques & Defenses 20 pts Security Threats20 pts

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Final Project – Grading Rubric

Any Questions?

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Pam Van HookEmail: [email protected]