IT Essentials: PC Hardware and Software 1 Chapter 7 Windows NT/2000/XP Operating Systems.

IT Essentials: PC Hardware and Software 1

Chapter 7

Windows NT/2000/XP

Operating Systems


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.


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.


FAT16

•The FAT structure also maintains a set of attributes for each file.

•S which stands for a system dataset

•H which means that the file is hidden in the directory display

•A which means that the file will be archived the next time the

disk is backed up

•R which will make the file Read-Only.


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.


NTFS

•The Windows NT File System (NTFS) supports all Windows

NT/2000/XP operating systems.

•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.

•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).


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.


High Performance File System

•HPFS) is a seldom used and much more obscure type of file

system but it is worth mentioning only because the OS/2

software that uses this file system is still in use today. Microsoft

did use this file system with its Windows 3.51 operating system.

•The HPFS file system directory structure was the same as the

FAT file system but allowed long file names of up to 254

characters.

•Another aspect of HPFS was its ability to map hard disks up to 8

GB instead of 2 GB.

•Instead of clusters as the unit of management on the hard disk,

HPFS used physical sectors.


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.


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.


Folder Permissions


File Permissions


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.


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


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.


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.


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.


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.


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.


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.


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.


Dynamic Disk Volumes

•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.


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.

IT Essentials: PC Hardware and Software 1 Chapter 7 Windows NT/2000/XP Operating Systems.

Documents

Transcript of IT Essentials: PC Hardware and Software 1 Chapter 7 Windows NT/2000/XP Operating Systems.