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11.7 the Windows 2000 File System
830 CASE STUDY 2: WINDOWS 2000 CHAP. 11 11.7 THE WINDOWS 2000 FILE SYSTEM Windows 2000 supports several file systems, the most important of which are FAT-16, FAT-32, and NTFS (NT File System). FAT-16 is the old MS-DOS file system. It uses 16-bit disk addresses, which limits it to disk partitions no larger than 2 GB. FAT-32 uses 32-bit disk addresses and supports disk partitions up to 2 TB. NTFS is a new file system developed specifically for Windows NT and car- ried over to Windows 2000. It uses 64-bit disk addresses and can (theoretically) support disk partitions up to 264 bytes, although other considerations limit it to smaller sizes. Windows 2000 also supports read-only file systems for CD-ROMs and DVDs. It is possible (even common) to have the same running system have access to multiple file system types available at the same time. In this chapter we will treat the NTFS file system because it is a modern file system unencumbered by the need to be fully compatible with the MS-DOS file system, which was based on the CP/M file system designed for 8-inch floppy disks more than 20 years ago. Times have changed and 8-inch floppy disks are not quite state of the art any more. Neither are their file systems. Also, NTFS differs both in user interface and implementation in a number of ways from the UNIX file system, which makes it a good second example to study. NTFS is a large and complex system and space limitations prevent us from covering all of its features, but the material presented below should give a reasonable impression of it. -
Openvms: an Introduction
The Operating System Handbook or, Fake Your Way Through Minis and Mainframes by Bob DuCharme VMS Table of Contents Chapter 7 OpenVMS: An Introduction.............................................................................. 7.1 History..........................................................................................................................2 7.1.1 Today........................................................................................................................3 7.1.1.1 Popular VMS Software..........................................................................................4 7.1.2 VMS, DCL................................................................................................................4 Chapter 8 Getting Started with OpenVMS........................................................................ 8.1 Starting Up...................................................................................................................7 8.1.1 Finishing Your VMS Session...................................................................................7 8.1.1.1 Reconnecting..........................................................................................................7 8.1.2 Entering Commands..................................................................................................8 8.1.2.1 Retrieving Previous Commands............................................................................9 8.1.2.2 Aborting Screen Output.........................................................................................9 -
“Application - File System” Divide with Promises
Bridging the “Application - File System” divide with promises Raja Bala Computer Sciences Department University of Wisconsin, Madison, WI [email protected] Abstract that hook into the file system and the belief that the underlying file system is the best judge File systems today implement a limited set of when it comes to operations with files. Unfor- abstractions and semantics wherein applications tunately, the latter isn’t true, since applications don’t really have much of a say. The generality know more about their behavior and what they of these abstractions tends to curb the application need or do not need from the file system. Cur- performance. In the global world we live in, it seems rently, there is no real mechanism that allows reasonable that applications are treated as first-class the applications to communicate this informa- citizens by the file system layer. tion to the file system and thus have some degree In this project, we take a first step towards that goal of control over the file system functionality. by leveraging promises that applications make to the file system. The promises are then utilized to deliver For example, an application that never ap- a better-tuned and more application-oriented file pends to any of the files it creates has no means system. A very simple promise, called unique-create of conveying this information to the file sys- was implemented, wherein the application vows tem. Most file systems inherently assume that never to create a file with an existing name (in a it is good to preallocate extra blocks to a file, directory) which is then used by the file system so that when it expands, the preallocated blocks to speedup creation time. -
MS-DOS Basics.Pdf
MS-DOS Basics The Command Prompt When you first turn on your computer, you will see some cryptic information flash by. MS-DOS displays this information to let you know how it is configuring your computer. You can ignore it for now. When the information stops scrolling past, you'll see the following: C:\> This is called the command prompt or DOS prompt. The flashing underscore next to the command prompt is called the cursor. The cursor shows where the command you type will appear. Type the following command at the command prompt: ver The following message appears on your screen: MS-DOS version 6.22 Viewing the Contents of a Directory To view the contents of a directory 1. Type the following at the command prompt: dir A list similar to the following appears: Changing Directories To change from the root directory to the WINDOWS directory To change directories, you will use the cd command. The cd command stands for "change directory." 1. Type the following at the command prompt: cd windows The command prompt changes. It should now look like the following: C:\WINDOWS> Next, you will use the dir command to view a list of the files in the DOS directory. Viewing the Contents of WINDOWS Directory To view a list of the files in the WINDOWS directory 1. Type the following at the command prompt: dir Changing Back to the Root Directory To change to the root directory 1. Type the following at the command prompt: cd \ Note that the slash you type in this command is a backslash (\), not a forward slash (/). -
MS-DOS Lecture
MS-DOS 2017 University of Babylon College of Engineering Electrical Department Learning Basics of MS-DOS Assis. Lec. Abeer Abd Alhameed | 1 MS-DOS 2017 Outcomes: By the end of this lecture, students are able to: Define the MS-DOS system Log in MS-DOS commands system Display MS-DOS information on your computer Type basic commands of MS-DOS system (view directory contents, change directory, make directory) Assis. Lec. Abeer Abd Alhameed | 2 MS-DOS 2017 Learning of MS-DOS Basics: Definition - What does Microsoft Disk Operating System (MS- DOS) mean? The Microsoft Disk Operating System (MS-DOS) is an operating system developed for PCs (personal computers) with x86 microprocessors. It was the first widely-installed operating system in personal computers. It is a command-line-based system, where all commands are entered in text form and there is no graphical user interface. The Command Prompt: When you first turn on your computer, you will see some information flash by. MS-DOS displays this information to let you know how it is configuring your computer. You can ignore it for now. When the information stops scrolling past, you'll see the following: C:\> This is called the command prompt or DOS prompt. The flashing underscore next to the command prompt is called the cursor. The cursor shows where the command you type will appear. Typing a Command: This section explains how to type a command at the command prompt and demonstrates the "Bad command or file name" message. • To type a command at the command prompt 1. Type the following at the command prompt (you can type the command in either uppercase or lowercase letters): nul If you make a typing mistake, press the BACKSPACE key to erase the mistake, and then try again. -
CS 103 Lab 1 - Linux and Virtual Machines
CS 103 Lab 1 - Linux and Virtual Machines 1 Introduction In this lab you will login to your Linux VM and write your first C/C++ program, compile it, and then execute it. 2 What you will learn In this lab you will learn the basic commands and navigation of Linux/Unix, its file system, the GNU C/C++ compiler and a few basic applications such as Gedit. Important: The Linux operating system and environment shares a vast majority of commands and methods with Unix. 3 Background Information and Notes 3.1 Software to Install on your PC Start by following the course virtual machine installation instructions found at the link below. http://cs103.usc.edu/tools-and-links/installing-course-vm/ Below is a list of recommended software you should install that will be helpful over multiple courses in CS and EE. These tools allow you to access remote servers, run GUI apps on those servers, and transfer files between your PC and those servers. For Windows: FileZilla FTP – Available from : https://software.usc.edu/index.aspx XWin-32 – Available from : https://software.usc.edu/index.aspx PuTTY – Available from : https://software.usc.edu/index.aspx For Mac: X Server: http://developer.apple.com/opensource/tools/runningx11.html Fetch FTP – Available from : https://software.usc.edu/index.aspx Reference: http://www.usc.edu/its/unix/ Last Revised: 8/29/2014 1 CS 103 Lab 1 - Linux and Virtual Machines 3.2 Getting Started with Unix1 and Accessing your Account Solaris vs. Unix vs. Linux UNIX was developed by AT&T Bell Labs in 1969. -
Verifying a High-Performance Crash-Safe File System Using a Tree Specification
Verifying a high-performance crash-safe file system using a tree specification Haogang Chen,y Tej Chajed, Alex Konradi,z Stephanie Wang,x Atalay İleri, Adam Chlipala, M. Frans Kaashoek, Nickolai Zeldovich MIT CSAIL ABSTRACT 1 INTRODUCTION File systems achieve high I/O performance and crash safety DFSCQ is the first file system that (1) provides a precise by implementing sophisticated optimizations to increase disk fsync fdatasync specification for and , which allow appli- throughput. These optimizations include deferring writing cations to achieve high performance and crash safety, and buffered data to persistent storage, grouping many trans- (2) provides a machine-checked proof that its implementa- actions into a single I/O operation, checksumming journal tion meets this specification. DFSCQ’s specification captures entries, and bypassing the write-ahead log when writing to the behavior of sophisticated optimizations, including log- file data blocks. The widely used Linux ext4 is an example bypass writes, and DFSCQ’s proof rules out some of the of an I/O-efficient file system; the above optimizations allow common bugs in file-system implementations despite the it to batch many writes into a single I/O operation and to complex optimizations. reduce the number of disk-write barriers that flush data to The key challenge in building DFSCQ is to write a speci- disk [33, 56]. Unfortunately, these optimizations complicate fication for the file system and its internal implementation a file system’s implementation. For example, it took 6 years without exposing internal file-system details. DFSCQ in- for ext4 developers to realize that two optimizations (data troduces a metadata-prefix specification that captures the writes that bypass the journal and journal checksumming) properties of fsync and fdatasync, which roughly follows taken together can lead to disclosure of previously deleted the behavior of Linux ext4. -
How to Load Vista Or Windows 7 Onto a Bootable Thumb Drive
STAR Watch Statewide Technology Assistance Resources Project A publication of the Western New York Law Center,Inc. Volume 15 Issue 5 Sept-Oct 2011 How to Load Vista or Windows 7 onto a Bootable Thumb Drive Ever since the capacity of USB thumb more robust. What happens when a drives rose into the multi-gigabyte range, DVD gets scratched? computer geeks have been trying to use them to create bootable devices that • Some of the latest computers don’t could be used in an emergency to boot have DVD drives, but they do have a up a failed computer. It was a wonderful USB port. idea, except for one detail: The driver • It takes less time to re-install needed to read the Windows install files Windows from a thumb drive could not be accessed. With the release of Vista and Windows 7 operating Find yourself a suitable thumb drive. It systems, the drivers needed to read the might be possible to shoehorn the files have been made more accessible. It Windows software onto a 4GB thumb is now possible to create a bootable drive, but that would leave no room for thumb drive that can be used to boot up anything else (It might be nice to have a computer and install Windows. copies of the install programs for things like printer drivers or other software that So, what is the big deal? Isn’t a DVD good enough? For many people, a DVD is quite adequate. Just store it in a safe In this issue… place and pull it out when it is needed. -
Linux File System and Linux Commands
Hands-on Keyboard: Cyber Experiments for Strategists and Policy Makers Review of the Linux File System and Linux Commands 1. Introduction Becoming adept at using the Linux OS requires gaining familiarity with the Linux file system, file permissions, and a base set of Linux commands. In this activity, you will study how the Linux file system is organized and practice utilizing common Linux commands. Objectives • Describe the purpose of the /bin, /sbin, /etc, /var/log, /home, /proc, /root, /dev, /tmp, and /lib directories. • Describe the purpose of the /etc/shadow and /etc/passwd files. • Utilize a common set of Linux commands including ls, cat, and find. • Understand and manipulate file permissions, including rwx, binary and octal formats. • Change the group and owner of a file. Materials • Windows computer with access to an account with administrative rights The Air Force Cyber College thanks the Advanced Cyber Engineering program at the Air Force Research Laboratory in Rome, NY, for providing the information to assist in educating the general Air Force on the technical aspects of cyberspace. • VirtualBox • Ubuntu OS .iso File Assumptions • The provided instructions were tested on an Ubuntu 15.10 image running on a Windows 8 physical machine. Instructions may vary for other OS. • The student has administrative access to their system and possesses the right to install programs. • The student’s computer has Internet access. 2. Directories / The / directory or root directory is the mother of all Linux directories, containing all of the other directories and files. From a terminal users can type cd/ to move to the root directory. -
Comparative Analysis of Distributed and Parallel File Systems' Internal Techniques
Comparative Analysis of Distributed and Parallel File Systems’ Internal Techniques Viacheslav Dubeyko Content 1 TERMINOLOGY AND ABBREVIATIONS ................................................................................ 4 2 INTRODUCTION......................................................................................................................... 5 3 COMPARATIVE ANALYSIS METHODOLOGY ....................................................................... 5 4 FILE SYSTEM FEATURES CLASSIFICATION ........................................................................ 5 4.1 Distributed File Systems ............................................................................................................................ 6 4.1.1 HDFS ..................................................................................................................................................... 6 4.1.2 GFS (Google File System) ....................................................................................................................... 7 4.1.3 InterMezzo ............................................................................................................................................ 9 4.1.4 CodA .................................................................................................................................................... 10 4.1.5 Ceph.................................................................................................................................................... 12 4.1.6 DDFS .................................................................................................................................................. -
Jailbreak Ios 12.1.1 As a Case Study
OPEN ACCESS Ind. Journal on Computing ISSN 2460-9056 Vol. 4, Issue. 2, Sept 2019. pp. 205-218 socj.telkomuniversity.ac.id/indojc doi:10.21108/indojc.2019.4.2.349 Digital Forensic Analysis on iDevice: Jailbreak iOS 12.1.1 as a Case Study Amin Aenurahman Ali 1, Niken Dwi Wahyu Cahyani 2, Erwid Musthofa Jadied 3 1,2,3 Informatics, School of Computing, Telkom University Jl. Telekomunikasi No. 1 Terusan Buah Batu, Bandung, Indonesia 1 [email protected] 2 [email protected] 3 [email protected] Abstract Jailbreak has an issue in data alteration, as it modifies file(s) in the device to allow user to extract more data than without jailbreaking. This issue raises controversy of the use of jailbreaking in digital forensic investigation, as data integrity is a prominent requirement in a court proceeding. This study aims to analyze the process of jailbreak, what is actually done by the jailbreak code in a device, and what data is actually modified by the jailbreak code. By using the latest version of iOS system, this study uses the voucher_swap exploit as a representation of semi-tethered jailbreaking method to investigate the effects of jailbreak on data integrity on a idevice. The investigation is conducted based on to what extent data can be extracted from the jailbreak device, hash value comparison of the data, and source code analysis to scrutinize the effect of jailbreak to the system and user data inside the device. Results of this study suggest that jailbreak is acceptable to prepare idevice in digital forensic investigations to acquire more data, as it maintains the integrity of user data. -
Operating Systems File Systems
COS 318: Operating Systems File Systems: Abstractions and Protection Jaswinder Pal Singh Computer Science Department Princeton University (http://www.cs.princeton.edu/courses/cos318/) Topics ◆ What’s behind the file system: Storage hierarchy ◆ File system abstraction ◆ File system protection 3 Traditional Data Center Storage Hierarchy WAN … LAN SAN Remote mirror Storage Server Clients Storage Offsite Onsite backup Backup 4 Evolved Data Center Storage Hierarchy WAN … LAN Remote Network mirror Attached w/ snapshots to protect data Clients Storage (NAS) Storage Offsite Onsite backup Backup 5 Alternative with no Tape WAN … LAN Remote Network mirror Attached w/ snapshots to protect data Clients Storage (NAS) Onsite Remote Backup Backup “Deduplication” WAN Capacity and bandwidth optimization 6 “Public Cloud” Storage Hierarchy … WAN WAN Interfaces Geo-plex Clients Examples: Google GFS, Spanner, Apple icloud, Amazon S3, Dropbox, Mozy, etc 7 Topics ◆ What’s behind the file system: Storage hierarchy ◆ File system abstraction ◆ File system protection 3 Revisit File System Abstractions ◆ Network file system ! Map to local file systems ! Exposes file system API ! NFS, CIFS, etc Network File System ◆ Local file system ! Implement file system abstraction on Local File System block storage ! Exposes file system API ◆ Volume manager Volume Manager ! Logical volumes of block storage ! Map to physical storage Physical storage ! RAID and reconstruction ! Exposes block API ◆ Physical storage ! Previous lectures 8 Volume Manager ◆ Group multiple storage partitions into a logical volume ! Grow or shrink without affecting existing data ! Virtualization of capacity and performance ◆ Reliable block storage ! Include RAID, tolerating device failures ! Provide error detection at block level ◆ Remote abstraction ! Block storage in the cloud ! Remote volumes for disaster recovery ! Remote mirrors can be split or merged for backups ◆ How to implement? ! OS kernel: Windows, OSX, Linux, etc.