CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [185]
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NOTE If you have a geeky interest in what version of NTFS you are running, open up a prompt and type this command: fsutil fsinfo ntfsinfo c:
NTFS Structure
NTFS utilizes an enhanced file allocation table called the master file table (MFT). An NTFS partition keeps a backup copy of the most critical parts of the MFT in the middle of the disk, reducing the chance that a serious drive error can wipe out both the MFT and the MFT copy. Whenever you defragment an NTFS partition, you’ll see a small, immovable chunk in the middle of the drive; that’s the backup MFT (Figure 12-20). It’s a little difficult to see in black and white, but the color image shows bright green in both the key at the bottom of the screen and in the estimated disk usage bars.
Figure 12-20 An NTFS MFT appears in a defragmenter program as an immovable file.
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EXAM TIP Both of the CompTIA A+ exams test you on NTFS, such as when to use it, what advantages it has over FAT32, and how to lock down information. You’ll also be quizzed on the tools, such as Disk Management, in both exams. Don’t skip anything in this chapter!
Security
NTFS views individual files and folders as objects and provides security for those objects through a feature called the access control list (ACL). Future chapters go into this in much more detail, but a quick example here should make the basic concept clear.
Suppose Bill the IT Guy sets up a Windows XP PC as a workstation for three users: John, Wilma, and Felipe. John logs into the PC with his user name and password (johns and f3f2f1f0, respectively, in case you’re curious) and begins to work on his project. The project folder is stored on the C: drive as C:\Projects\JohnSuperSecret. When John saves his work and gets ready to leave, he alters the permissions on his folder to deny access to anyone but him. When curious Wilma logs into the PC after John leaves, she cannot access the C:\Programs\JohnSuperSecret folder contents at all, although she can see the entry in Explorer. Without the ACL provided by NTFS, John would have no security over his files or folders at all.
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NOTE Microsoft has never released the exact workings of NTFS to the public.
Compression
NTFS enables you to compress individual files and folders to save space on a hard drive. Compression makes access time to the data slower because the OS has to uncompress files every time you use them, but in a space-limited environment, sometimes that’s what you have to do.
Encryption
One of the big draws with NTFS is file encryption, the black art of making files unreadable to anybody who doesn’t have the right key. You can encrypt a single file, a folder, or a folder full of files. Microsoft calls the encryption utility in NTFS the encrypting file system (EFS), but it’s simply an aspect of NTFS, not a standalone file system. To encrypt a file or folder, right-click it in My Computer or Computer and select Properties to open the Properties dialog box (Figure 12-21). Click the Advanced button to open the Advanced Attributes dialog box. As you can see in Figure 12-22, encryption (and compression) is simply a selectable checkbox. Click the box next to Encrypt contents to secure data and then click the OK button—instantly your file is safe from prying eyes!
Figure 12-21 Folder Properties
Figure 12-22 Options for compression and encryption
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EXAM TIP Windows XP Home and Media Center editions do not support EFS.
Encryption does not hide files; it simply makes them unreadable to other users. Figure 12-23 shows a couple of image files encrypted by another user. Note that in addition to the pale green color of the filenames (that you can’t tell are pale green in this black-and-white image),