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228 Chapter 4 ■ Understanding Operating Systems Older versions of Windows (Windows 3.x and Windows 95 original release) as well as all versions of DOS cannot read FAT32 partitions. NT File System (NTFS) Introduced along with Windows NT (and available on 2000/XP). NTFS is a much more advanced file system in almost every way than all versions of the FAT file system. It includes such features as individual file security and compression, RAID sup-port, as well as support for extremely large file and partition sizes and disk transaction mon-itoring. It is the file system of choice for higher-performance computing. When you’re installing any Windows OS, you will be asked first to format the drive using one of these disk technologies. Choose the disk technology based on what the computer will be doing and which OS you are installing. To create a FAT16 or FAT32 partition, you can use the FDISK command. To format a parti-tion, you can use the FORMAT command. FDISK.EXE is available only with Windows 9x/Me (not 2000/XP), and you can run it from a command prompt. FORMAT.EXE is available with all versions of Windows. You can run FORMAT from a command prompt or by right-clicking a drive in Win-dows Explorer and selecting Format. However, when you install Windows it performs the process of partitioning and formatting for you if a partitioned and formatted drive does not already exist. Be extremely careful with the FORMAT command! When you format a drive, all data on the drive is erased. In Windows 2000/XP, you can manage your hard drives through the Disk Management component. To access Disk Management, access the Control Panel and double-click Admin-istrative Tools. Then, double-click Computer Management. Finally, double-click Disk Man-agement. The Disk Management screen looks similar to the one shown in Figure 4.17. The Disk Management screen lets you view a host of information regarding all the drives installed in your system, including CD-ROM and DVD drives. In Figure 4.17, you can see that this computer has three disks (Disk 0, Disk 1, and Disk 2), one DVD (CD-ROM 0), and one CD-ROM (CD-ROM 1) drive installed. In this example, you can see that Disk 0 has four partitions. A different drive letter is assigned to each partition on Disk 0 (C:, D:, G:, and H:). The list of devices in the top portion of the screen shows you additional information for each partition on each drive, such as the file system used, status, free space, and so on. If you right-click a partition in either area, you can perform a variety of functions, such as formatting the partition and changing the name and drive-letter assignment. For additional options and information, you can also access the Properties of a partition by right-clicking it and selecting Properties. Windows 2000 and XP Professional support both basic and dynamic storage. The partition that the operating system boots from must be designated as active. Only one partition on a disk may be marked active. With basic storage, Windows 2000 and XP Professional drives can be partitioned with primary or extended partitions. The difference is that extended partitions can be divided into one or more logical drives and primary partitions cannot be further sub-divided. Each 2000/XP Professional hard disk can be divided into a total of four partitions, either four primary partitions or three primary and one extended partition. Using Operating Systems 229 FIGURE 4.17 The Disk Management screen Finally, there is the concept of a logical partition. In reality, all partitions are logical in the sense that they don’t necessarily correspond to one physical disk. One disk can have several logical divisions (partitions). A logical partition is any partition that has a drive letter. Sometimes, you will also hear of a logical partition as one that spans multiple physical disks. For example, a network drive that you know as drive H: might actually be located on several physical disks on a server. To the user, all that is seen is one drive, or H:. Backing Up the Data on Your Drives Another very important aspect of disk management is backing up the data on your drives. Sooner or later, you can count on running into a situation where a hard drive fails or data becomes corrupted. Without a backup copy of your data, you’re facing a world of trouble try-ing to re-create the data, if that’s even possible or economically feasible. You also shouldn’t rely on the Recycle Bin. Although it is a good utility to restore an occasional file or directory that a user has accidentally deleted, it will not help you if your drives and the data on them become unusable. Toward that end, Windows has a built-in backup feature called, you guessed it, Backup. To access Backup, click Start ⮚ Programs (All Programs) ⮚ Accessories ⮚ System Tools ⮚ Backup. This will open the Backup Wizard. To move on to the Backup utility, click Advanced Mode. Fig-ure 4.18 shows the Windows 2000 Backup utility with the Backup tab selected. 230 Chapter 4 ■ Understanding Operating Systems FIGURE 4.18 The Windows 2000 Backup utility with the Backup tab selected The Backup utility in each of the different versions of Windows has different capabilities, with newer versions having greater capabilities. In general, you can either run a wizard to cre-ate a backup job or manually specify the files to back up. You can also run backup jobs or schedule them to run at specific time at a specific interval. Refer to the Windows Help system for in-depth information on how to use Backup. Checking the Health of Hard Disks and Optimizing Their Performance As time goes on, it’s important to check the health of Windows computers’ hard disks and optimize their performance. Windows provides you with several tools to do so, some of which we’ve already mentioned in this chapter. One important tool is Disk Defragmenter, which exists in all versions of Windows except Windows NT. When files are written to a hard drive, they’re not always written contiguously. As a result, file data is spread out over the disk, and the time it takes to retrieve files from disk increases. Defragmenting a disk involves analyzing the disk and then consolidating fragmented files and folders so they occupy a contiguous space, thus increasing performance during file retrieval. To access Disk Defragmenter, click Start ⮚ Programs (All Programs) ⮚ Accessories ⮚ Sys-tem Tools ⮚ Disk Defragmenter. In the list of drives, select the drive you want to defragment, and then click Analyze. When the analysis is finished, Disk Defragmenter tells you how much the drive is defragmented and whether defragmentation is recommended. If it is, click Defrag-ment. Be aware that for large disks with a lot of fragmented files, this process can take quite some time to finish. Using Operating Systems 231 In Windows 2000/XP, you can also access Disk Defragmenter through the Properties of any partition listed in Disk Management. Click the Tools tab and then click Defragment. File Management File management is the process by which a computer stores data and retrieves it from storage. Although some of the file-management interfaces across Windows interfaces may have a dif-ferent look and feel, the process of managing files is similar across the board. Files and Folders For a program to run, it must be able to read information off the disk and write information back to the disk. In order to be able to organize and access information—especially in larger new systems that may have thousands of files—it is necessary to have a structure and an ordering process. Windows provides this process by allowing you to create directories, also known as folders, in which to organize files. Windows also regulates the way that files are named and the prop-erties of files. Each file created in Windows has to follow certain rules, and any program that accesses files through Windows also must comply with these rules. Files created on a Windows system must follow these rules: ■ Each file has a filename of up to 255 characters. ■ Certain characters, such as a period (.) and slash (\ or /), are prohibited in the filename. ■ An extension (generally three or four characters) can be added to identify the file’s type. ■ Filenames are not case sensitive. (You can create files with names that use both upper- and lowercase letters, but to identify the file within the file system, it is not necessary to adhere to the capitalization in the filename.) Thus, you cannot have a file named working.txt and another called WORKING.TXT in the same directory. To Windows, these filenames are identical, and you can’t have two files with the same filename in the same directory. We’ll get into more detail on this topic a little later. ■ In Windows 3.x and DOS, filenames were limited to eight characters and a three-charac-ter extension, separated by a period. This is also called the 8.3 file-naming convention. With Windows 95, long filenames were introduced, which allowed the 255-character file-name convention. The Windows file system is arranged like a filing cabinet. In a filing cabinet, paper is placed into folders, which are inside dividers, which are in a drawer of the filing cabinet. In the Win-dows file system, individual files are placed in subdirectories that are inside directories, which are stored on different disks or different partitions. Windows also protects against duplicate filenames, so no two files on the system can have exactly the same name and path. A path indicates the location of the file on the disk; it is composed of the logical drive letter the file is on and, if the file is located in a directory or subdirectory, the 232 Chapter 4 ■ Understanding Operating Systems names of those directories. For instance, if a file named AUTOEXEC.BAT is located in the root of the C: drive—meaning it is not within a directory—the path to the file is C:\AUTOEXEC.BAT. If, as another example, a file called FDISK.EXE is located in the Command directory under Windows under the root of C:, then the path to this file is C:\WINDOWS\COMMAND\FDISK.EXE. The root directory of any drive is the place where the hierarchy of folders for that drive begins. On a C: drive, for instance, C:\ is the root directory of the drive. Common file extensions you may encounter are .EXE for executable files (applications), .DLL for dynamic linked library (DLL) files, .SYS for system files, .LOG for log files, .DRV for driver files, .TXT for text files, and others. Note that DLL files contain additional functions and commands applications can use and share. In addition, most applications use specific file extensions for the documents created with each application. For example, documents created in Microsoft Word have a .DOC extension. You’ll also encounter extensions such as .MPG for video files, .MP3 for music files, .TIF and .JPG for graphics files, .HTM or .HTML for web pages, and so on. Being familiar with different filename extensions is helpful in working with the Windows filesystem. Capabilities of Windows Explorer Although it is technically possible to use the command-line utilities provided within the com-mand prompt to manage your files, this generally is not the most efficient way to accomplish most tasks. The ability to use drag-and-drop techniques and other graphical tools to manage the file system makes the process far simpler, and Windows Explorer is a utility that allows you to accomplish a number of important file-related tasks from a single graphical interface, as shown in Figure 4.19. FIGURE 4.19 The Windows Explorer program ... - tailieumienphi.vn
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