Hardware and Operating System Maintenance

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Hardware and Operating System Maintenance Powered By Docstoc
					                  Hardware and Operating System Maintenance

Learning Objectives
By the end of this lesson, you will be able to:
 Identify the characteristics of motherboards.
 Identify common IRQ, I/O address and DMA settings, and describe their functions.
 Identify the characteristics of IDE/ATA, EIDE/ATA-2, SATA and SCSI.
 Identify NICs and common peripheral ports, and describe their functions.
 Identify the characteristics of CD-ROMs and DVDs.
 Describe hard-drive partitioning and formatting.
 Describe the characteristics of file system types, including FAT, FAT32, NTFS, Ext3 and ReiserFS.
 Describe the uses of file system management tools, including Convert, Disk Defragmenter, Chkdsk, Disk Cleanup, Backup and Restore.
 Identify and suggest corrective measures for operating system boot problems and application failures.
 Identify methods to remotely mange and troubleshoot workstations.

   An interrupt is basically what it sounds like, a message from one part of the computer to another (normally to the
    system processor) that tells it that it needs to stop what it is doing, and do something else instead.
   An IRQ is an interrupt request, and is the name for the actual signal that is used when a peripheral requests an
    interrupt of the processor.
   Interrupts play a key role in how the processor performs input/output processing, and interfaces with every
    peripheral in the computer, from the keyboard and mouse to the hard disk and modem.

                                                          I/O address
   The term I/O is used to describe any program, operation or device that transfers data to or
    from a computer and to or from a peripheral device. Every transfer is an output from one
    device and an input into another. Devices such as keyboards and mouses are input-only
    devices while devices such as printers are output-only. A writable CD-ROM is both an input
    and an output device.

   Short for direct memory access, a technique for transferring data from main memory to a device without passing it
    through the CPU.
   Computers that have DMA channels can transfer data to and from devices much more quickly than computers
    without a DMA channel can.
   This is useful for making quick backups and for real-time applications. Some expansion boards, such as CD-ROM
    cards, are capable of accessing the computer's DMA channel. When you install the board, you must specify which
    DMA channel is to be used, which sometimes involves setting a jumper or DIP switch.

    Abbreviation of either Intelligent Drive Electronics or Integrated Drive Electronics, depending on who you ask. An
    IDE interface is an interface for mass storage devices, in which the controller is integrated into the disk or CD-ROM
   Although it really refers to a general technology, most people use the term to refer to the ATA specification, which
    uses this technology. Refer to ATA for more information.

   Short for Enhanced IDE, a newer version of the IDE mass storage device interface standard developed by Western Digital
    Corporation. It supports data rates of between 4 and 16.6 MBps, about three to four times faster than the old IDE standard. In
    addition, it can support mass storage devices of up to 8.4 gigabytes, whereas the old standard was limited to 528 MB. Because
    of its lower cost, enhanced EIDE has replaced SCSI in many areas. EIDE is sometimes referred to as Fast ATA or Fast IDE,
    which is essentially the same standard, developed and promoted by Seagate Technologies. It is also sometimes called ATA-2.
   There are four EIDE modes defined. The most common is Mode 4, which supports transfer rates of 16.6 MBps. There is also a
    new mode, called ATA-3 or Ultra ATA, that supports transfer rates of 33 MBps.

                                                   SATA - Serial ATA
   Often abbreviated SATA or S-ATA, is an evolution of the Parallel ATA physical storage interface.
   Serial ATA is a serial link -- a single cable with a minimum of four wires which creates a point-to-point connection between
   One of the main design advantages of Serial ATA is that the thinner serial cables facilitate more efficient airflow inside a
    computer case.
   In contrast, IDE cables used in parallel ATA systems are bulkier than Serial ATA cables and can only extend to 40cm long, while
    Serial ATA cables can extend up to one meter. Serial ATA supports all ATA and ATAPI devices.

                                                  SCSI - Small Computer System Interface
   Pronounced "scuzzy," SCSI is a parallel interface standard used by Apple Macintosh computers, PCs, and many UNIX systems
    for attaching peripheral devices to computers. SCSI interfaces provide for faster data transmission rates (up to 80 megabytes
    per second) than standard serial and parallel ports. In addition, you can attach many devices to a single SCSI port, so that SCSI
    is really an I/O bus rather than simply an interface.

                                             The following varieties of SCSI are currently implemented:

   SCSI-1: Uses an 8-bit bus, and supports data rates of 4 MBps
   SCSI-2: Same as SCSI-1, but uses a 50-pin connector instead of a 25-pin connector, and supports multiple devices. This is what
    most people mean when they refer to plain SCSI.
   Wide SCSI: Uses a wider cable (168 cable lines to 68 pins) to support 16-bit transfers.
   Fast SCSI: Uses an 8-bit bus, but doubles the clock rate to support data rates of 10 MBps.
   Fast Wide SCSI: Uses a 16-bit bus and supports data rates of 20 MBps.
   Ultra SCSI: Uses an 8-bit bus, and supports data rates of 20 MBps.
   SCSI-3: Uses a 16-bit bus and supports data rates of 40 MBps. Also called Ultra Wide SCSI.
   Ultra2 SCSI: Uses an 8-bit bus and supports data rates of 40 MBps.
   Wide Ultra2 SCSI: Uses a 16-bit bus and supports data rates of 80 MBps.

                                                 NIC - Network Interface Card
   an expansion board you insert into a computer so the computer can be connected to a
    network. Most NICs are designed for a particular type of network, protocol, and media,
    although some can serve multiple networks.

   Digital Versatile Disc or Digital Video Disc, a type of optical disk technology similar to the CD-ROM. A DVD holds a minimum of
    4.7GB of data, enough for a full-length movie. DVDs are commonly used as a medium for digital representation of movies and
    other multimedia presentations that combine sound with graphics.

   The DVD specification supports disks with capacities of 4.7GB to 17GB. One of the best features of DVD drives is that they are
    backward-compatible with CD-ROMs, meaning they can play old CD-ROMs and video CDs, as well as new DVD-ROMs. Newer
    DVD players can also read CD-R disks.

   DVD uses MPEG-2 to compress video data.

                                                       Hard-drive Partitioning
   The easiest way to understand the system drive structure is to use a tool supplied with Windows XP called Disk Management that's part of the Microsoft Management

   Formatting is organizing and marking the surface of a disk into tracks, sectors, and cylinders.

                                                       FAT - file allocation table
   A table that the operating system uses to locate files on a disk. Due to fragmentation, a file may be divided into many sections
    that are scattered around the disk. The FAT keeps track of all these pieces.

   In DOS systems, FATs are stored just after the boot sector.

   The FAT system for older versions of Windows 95 is called FAT16, and the one for new versions of Windows 95 and Windows 98
    is called FAT32.

   A version of the file allocation table (FAT) available in Windows 95 OSR 2 and Windows 98.
    FAT32 increases the number of bits used to address clusters and also reduces the size of
    each cluster. The result is that FAT32 can support larger disks (up to 2 terabytes) and has
    better storage efficiency (less slack space).

   NT File System, one of the file system for the Windows NT operating system (Windows NT also supports the FAT
    file system). NTFS has features to improve reliability, such as transaction logs to help recover from disk failures. To
    control access to files, you can set permissions for directories and/or individual files. NTFS files are not accessible
    from other operating systems such as DOS.

   For large applications, NTFS supports spanning volumes, which means files and directories can be spread out
    across several physical disks.

   Ext3 is a journaling file system developed by Stephen Tweedie. It is compatible to ext2 file systems; actually you
    can look at it as an ext2 file system with a journal file. The journaling capability means no more waiting for fsck's or
    worrying about metadata corruption. What is most noticeable is that you can switch back and forth between ext2
    and ext3 on a partition without any problem: it is just a matter of giving the mount command the right file system

   A newer Linux file system that is faster and more secure.

   This utility is used to convert from one file system to another. Windows XP includes a command line utility, convert.exe, that will convert a FAT or
    FAT32 drive to NTFS.

                                                       Disk Defragmenter
   Files get “fragmented” over time and can be reorganized to achieve better performance.

   A Windows NT utility used to check and repair disk problems.

Backup and Restore
   The Backup utility helps you protect data from accidental loss if your system experiences hardware or storage
    media failure. For example, you can use Backup to create a duplicate copy of the data on your hard disk and then
    archive the data on another storage device. The backup storage medium can be a logical drive such as your hard
    drive, or a separate storage device such as a removable disk, or an entire library of disks or tapes organized into a
    media pool and controlled by a robotic changer. If the original data on your hard disk is accidentally erased or
    overwritten, or becomes inaccessible because of a hard disk malfunction, you can easily restore the data from the
    archived copy.

Operating system boot problems and application failures
   Because the operating system is essential for running all other programs, it is usually the first piece of
    software loaded during the boot process.
   Boot is short for bootstrap, which in the past was a strap attached to the top of your boot that you could
    pull to help get your boot on. Hence, the expression "pull oneself up by the bootstraps." Similarly,
    bootstrap utilities help the computer get started.

Methods to remotely manage and troubleshoot workstations
   A remote computer is a computer that connects to other computers or network devices by using either
    a phone line or a wireless connection.
   Secure Shell (SSH) is probably the most popular remote administration tool. SSH offers command line
    access over an encrypted tunnel. Many Linux distributions come with an SSH server already installed.
    As with any tool, patches must be installed and restrictions should be put in place to keep unauthorized
    users from using the service.