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IT320 Operating System Concepts. Unit 7: File Management May 2012. Upcoming Topics. 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.
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Kaplan University IT320Operating System Concepts Unit 7: File Management May 2012
Upcoming Topics • 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 Kaplan University
Unit 7: Reading & Assignments • 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) Kaplan University
Unit 7: Discussion Question • Directory Structure – Linux vs Windows • 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. • http://www.ibm.com/developerworks/linux/library/l-linux-filesystem/ Kaplan University
Unit 7: Assignment • 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. Kaplan University
Unit 7: File Management • 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 Kaplan University
Unit 7: Grading Rubric • 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. Kaplan University
Chapter 12 – File Management Kaplan University
File Management Question 1 • What is file management? Kaplan University
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
File Management Question 3 • What are the basic requirements needed for a file management system on any operating system? Kaplan University
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
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 Kaplan University
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 their controllers or channels Kaplan University
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 Kaplan University
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
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
File Sharing • Access rights include • None • Knowledge • Execution • Reading • Appending • Updating • Changing Protection • Deletion Kaplan University
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
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
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
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
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
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
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
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 Kaplan University
Preview – Final Project Kaplan University
Final Project • 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 Kaplan University
Final Project • 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) Kaplan University
Final Project – Grading Rubric • 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 Kaplan University
Any Questions? • Pam Van HookEmail: pvanhook@kaplan.edu Kaplan University