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Module 6 Windows NT/2000/XP Operating Systems Version 3

File Systems • The main purpose of the file system is to store and retrieve data from the computer hard disk. How the data is organized, optimized, and retrieved comes from the file system on the hard drive. • There are three different file systems available in the Windows Operating System Environment: FAT16, FAT32, and NTFS. • When using Windows NT, 2000, or XP, the best file system to use would be NTFS. • Both FAT16 and FAT32 file systems maintain two copies of the FAT (the default and backup copy), but only FAT32 can use the backup copy as well as the default copy.

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FAT16 • The 16-bit FAT (FAT16) is used for most hard drives with DOS, Windows 3.1, and the first version of Windows 95. • It limits the file names to eight characters with a three-letter extension. • The FAT16 file system can only recognize partitions up to 2 GB in size. • In the FAT16 file system, the root directory can be located only at the beginning of the hard disk. This poses problems if this part of the hard disk becomes damaged.

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FAT32 • FAT32 is still based on the original FAT system and works in a similar fashion in order to remain compatible with existing programs, networks, and device drivers. • The FAT32 file system was designed to support hard drives up to 2048 GB. • FAT32 file system, the root directory can be located anywhere on the hard disk. This is very useful because if the section of the hard disk containing the root directory were to become damaged now, the root directory could be moved to another section of the hard disk and the damaged portion of the hard disk could be repaired. Version 3

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NTFS •

The Windows NT File System (NTFS) supports all Windows NT/2000/XP operating systems.

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NTFS5 (the latest version) also includes a feature called disk quotas, which provide the system administrator with the ability to assign limits to the amount of hard disk space that users are allowed to occupy on the server or workstation.

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NTFS file system provides support for added features like file and directory security by using Discretionary Access Control Lists (DACL) and System Access Control Lists (SACL).

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NTFS offers better file utilization, more administrative tools, and increased security.

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NTFS • The Windows NT/2000/XP operating systems were designed to appeal to the corporate and business market. • If the system crashes, NTFS can examine the log file and use it to restore the disk to a consistent state with minimal data loss. This feature is called Fault Tolerance.

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Sectors and Clusters • The hard disk is divided into 512-byte pieces called sectors. • The sectors are then grouped into larger pieces called clusters. Each cluster can hold only one file. • The size of the clusters is determined by the size of the partitions made on the hard disk.

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NTFS Security and Permissions • Windows NT/2000/XP has enhanced system security features like file encryption and the ability to set permissions on files as well as directories or folders. • File and directory permissions are used to specify which users and groups can gain access to files and folders and what they can do with the contents of the file or folder. • Another security feature included with the Windows 2000/XP operating systems, provided NTFS is used, is encryption. • These features are only available in the Windows NT/2000/XP operating systems if NTFS is used and not the FAT file system. Version 3

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Folder Permissions

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File Permissions

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Encryption • Microsoft provides a specific file system for encryption called the Encrypting File System (EFS). • This provides administrators with the means to apply encryption to a file or folder that only the person who encrypted the file can view. • The administrator can specify the users who can view the file as well. Users can be granted access to the file if they are assigned a public key.

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Windows 2000 Boot Process • The Boot Process of the Windows 2000 operating system is very different from Windows 9x. The Windows 9x boot process is much simpler and straightforward. • The Windows 2000 boot process occurs in five stages: • The preboot sequence • The boot sequence • The kernel load • The kernel initialization • The logon process Version 3

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Preboot Process • The first step in the Boot Process after the power is turned on to the computer is the Power On Self Test (POST). • After the POST routine is complete, the computer will locate a boot device, and load the Master Boot Record (MBR) into memory, which in turn locates the active partition and loads it into memory. • The MBR allows programs such as the Disk Operating System to load into RAM.

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Boot Sequence • The boot sequence begins to gather information about hardware and drivers. NTLDR is the key component of this step. NTLDR uses the following files: Ntdetect.com, Boot.ini, and Bootsect.dos (The Bootsect.dos file will only be used in the event that the computer is set up to dual-boot.) • The Boot.ini file enables the display of the boot menu on the screen. • Ntdetect.com will detect hardware • Once Ntdetect.com has collected the hardware information, NTLDR will load Ntoskrnl.exe and pass that information.

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Kernal Load •The Kernel Load phase begins with Ntoskrnl.exe loading along with the Hal.dll file.

Kernal Initialization •This simply means that it is recognizing everything that was loaded previously so that NTLDR can now give control to the operating system kernel. •The operating system can now begin the final stages of loading. •The Graphical User Interface (GUI) is now seen and it will show a status bar indicating that the GUI is now loading. Version 3

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Logon • The Logon screen begins the final step in the boot-up process. • Although this is the final step, it is not considered a completed or successful boot until a user logs on.

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Device Drivers • Device drivers are programs that basically tell the operating system how to control specific devices. • They act as an interface between the operating system and the device, which allows them to recognize and communicate with each other. • The ability to add many devices to modern computers to expand their capabilities has become increasingly easier with the advances made in Plug-and-play Technology. • The goal of Plug-and-play is to create a computer whose hardware and software work together to automatically configure devices and assign resources. Version 3

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Administrative Tools • The Administrative Tools utility is a powerful Windows NT/2000/XP System Tool that enables the administrator to control just about everything related to the local computer. • From this utility, permission to log on to the computer can be controlled by creating Local User accounts. • The Disk Management utility allows the administrator to control and manipulate the computer hard drives. • There is also a Services tab that can start or stop any of the programs that are running on the computer.

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Disk Types • There are two types of disks that are available in Windows 2000 and XP, basic disks and dynamic disks. – Basic Disk storage is typically referred to as the industry standard and is identified by a hard drive that is divided into partitions. – When using Dynamic Disk Storage, multidisk volumes are referred to as hard disk space. This is because the hard drives are no longer dealt with as if they were one complete disk divided by partitions, but rather as multidisk volumes.

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Disk Types • The three types of volumes that can be created with Windows 2000 professional are simple, striped, and spanned volumes. – Simple Volume – Acts as a basic disk that will contain disk space from a complete single disk and is not fault tolerant. – Spanned Volume – This volume will include disk space from multiple disks. There can be up to 32 disks in a spanned volume. – Striped Volume – Also known as RAID-0, a stripped volume combines areas of free space from multiple hard disks, up to 32, into one logical volume. Version 3

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Dynamic Disk Volumes • Mirrored and RAID-5 volumes are types of volumes that can only be created with the Windows 2000 Server operating system. • Mirrored volumes provide fault tolerance. It contains two identical copies of a simple volume that stores the same data on two separate hard drives. • RAID-5 Volume - in the event that one of the drives should fail, the remaining two disks recreate the data automatically without having to shut down the server. • RAID-5 provides disk striping with parity and must be created on three to 32 drives Version 3

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