Disks and Formatting

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Chapter 3. Disks and Formatting. Overview. The need for formatting a disk will be discussed. Overview. The difference between partitioning and formatting a disk will be explained. Overview. The structure of a disk will be described. Overview. - PowerPoint PPT Presentation

Text of Disks and Formatting

  • Disks andFormatting

    Ch 3

  • Overview

    The need for formatting a disk will be discussed.

    Ch 3

  • Overview

    The difference between partitioning and formatting a disk will be explained.

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  • Overview

    The structure of a disk will be described.

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  • Overview

    Will learn to format a disk, electronically label it, and then how to change the label.

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  • Overview

    Various file systems will be compared and contrasted.

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  • Overview

    Some of the parameters that can be used with the FORMAT command will be discussed and then used with the FORMAT command.

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  • Why Format a Disk?Disks used for:Permanent storage of data and programsDistributing data from one computer to another Making copies

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  • Why Format a Disk?Formatting (initializing) the disk:Process of preparing disk so that it is compatible with an operating system

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  • Why Format a Disk?

    All disks (including hard disks) must be formatted.

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  • Partitioning and Formatting DisksHard disks must be: Partitioned Formatted with file system

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  • Partitioning and Formatting DisksPartition terms: Primary partition Partition table Volume Active partition Extended partition

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  • Partitioning and Formatting DisksDual booting system:Create partition for each OSOnly one OS active at a timeEach OS formats disks in own way Precautions in running multiple OS

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  • Partitioning and Formatting DisksFile system: Organizational scheme of OSOS is what makes one computer compatible with another

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  • Partitioning and Formatting Disks

    Windows XP Professional supports four file systems: NTFS Three FAT file systems -FAT12 FAT16 FAT32

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  • Partitioning and Formatting DisksTypes of disk storage configuration: Basic disks Dynamic disks

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  • Structure of a Disk

    Two parts to formatting a disk: Low-level (physical) formatting High level (logical) formatting

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  • Structure of a DiskLow-level (physical) formatting:Sequentially numbers tracks and sectorsIdentifies each track and sectorDisk is physically prepared to hold data

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  • Structure of a DiskHigh-level (logical) formatting: Determines how OS uses a diskBuilds structure to keep track of location of filesDone so files can be stored and retrieved.

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  • Structure of a DiskWindows XP Professional monitors status of all disk data sectors.

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  • Structure of a DiskOne or more sectors are combined into logical units called clusters or allocation units.

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  • Structure of a Disk

    Cluster (allocation unit):Smallest unit that OS can work with

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  • Structure of a DiskCluster overhang: Wasted space on the disk.

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  • Structure of a Disk Master Boot Record & Boot Sector

    Master boot record (MBR):First part of hard diskLocates bootable partition of hard disk and gives control over to it

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  • Structure of a Disk Master Boot Record & Boot Sector

    Boot sector: First sector on logical drive Has table of drives characteristics Has bootstrap loader program

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  • Structure of a Disk Master Boot Record & Boot Sector

    All disks (including non-system disks) have a boot sector.

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  • Structure of a Disk Master Boot Record & Boot Sector

    FAT non-system error messages: Non-system disk or disk error Replace disk and press any key when ready

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  • Structure of a Disk Master Boot Record & Boot Sector

    NTFS non-system error messages: Invalid partition table Error loading operating system Missing operating system

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  • Structure of a Disk Master Boot Record & Boot Sector

    Floppy disk non-system error messages: NTLDR is missing Press any key to restart

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  • Structure of a Disk Master Boot Record & Boot Sector

    Windows uses boot sector to identify the type of disk.

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  • Structure of a Disk FAT16, VFAT & FAT32

    FATs formatting program creates: Boot record File Allocation Table (2 copies) Root directory

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  • Structure of a Disk FAT16, VFAT & FAT32 Fig 3.1 Logical Structure of a Disk p. 100

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  • Structure of a Disk FAT16, VFAT & FAT32

    FAT is a map of disks data clusters.

    FAT number indicates status of cluster.Numbers in FAT link clusters that belong to same file

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  • Structure of a Disk FAT16, VFAT & FAT32Table 3.1 Cluster Size and Disk Size p. 100

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  • Structure of a Disk FAT16, VFAT & FAT32

    FAT essential for:Managing dataFollowing trail of clusters that make up a file

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  • Structure of a Disk FAT16, VFAT & FAT32

    VFAT maintains backwards compatibility and accommodates long file names.

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  • Structure of a Disk FAT16, VFAT & FAT32FAT32:Enhancement of FAT file systemIntroduced to overcome limitations of VFATDoes not apply to floppy drives

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  • Structure of a Disk FAT16, VFAT & FAT32Table 3.2 Comparison of FAT and FAT32 p. 101

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  • Structure of a Disk FAT16, VFAT & FAT32FAT32:Movable Root Directory Can be located anywhere on hard diskCan use backup copy of FATInternal backup copy of some critical FAT data structuresEntries in Root Directory limited

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  • Structure of a Disk FAT16, VFAT & FAT32With smaller clusters: More clusters on partition FAT larger - store more data Takes longer to locate/access file

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  • Structure of a Disk FAT16, VFAT & FAT32With larger clusters:Table smaller Takes less time to locate/access fileIncreases wasted disk space from cluster overhang

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  • Structure of a Disk FAT16, VFAT & FAT32

    FAT32 is best for many small files.

    FAT is best for mostly large files.

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  • Structure of a Disk The Root Directory

    Root Directory:Table that records information about each file on the disk

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  • Structure of a Disk The Root Directory

    Changes in root directory table make Windows XP Professional compatible with older Windows and DOS programs.

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  • Structure of a Disk FAT and the Root Directory

    Root directory tells what is on the disk. FAT tells where data is on the disk.

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  • Structure of a Disk FAT and the Root Directory

    Number in FAT points to next cluster that holds data in file.

    EOF (end-of-file) marker indicates there is no more data in file.

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  • Structure of a Disk FAT and the Root DirectoryFig 3.2 The Root Directory and FAT p. 103

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  • Structure of a Disk Data Portion or the Files AreaLargest part of disk is used for storing files.

    Space is allocated to files on an as-needed basis.

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  • Structure of a Disk Data Portion or the Files AreaA file is written to a disk in: Contiguous clusters or Noncontiguous clusters.

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  • Structure of a Disk Understanding FAT & Root Directory TableFig 3.3 Storing Files p. 105

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  • Structure of a Disk NTFS

    File system used determines OS advanced features available to user.

    For disk security, performance, and efficiency use NTFS file system.

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  • Structure of a Disk NTFSAdvantages of NTFS: Secure file system Efficient storage of data Faster file access Better data recovery Can compress files/assign disk quotas Encryption of files

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  • Structure of a Disk Clusters and NTFS

    NTFS: Uses FAT cluster scheme for allocating data.Has less overhead.

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  • Structure of a Disk Clusters and NTFSTable 3.3 NTFS Cluster Size p. 106

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  • Structure of a Disk Clusters and NTFSFig 3.4 Structure of an NTFS Volume p. 106

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  • Structure of a Disk Master File Table (MFT)Master File Table (MFT):Database of all files in systemUsed by NTFS to track all files and directories in a volume Dynamic

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  • Structure of a Disk Master File Table (MFT)

    MFT is different from FAT.

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  • Structure of a Disk Master File Table (MFT)MFT:Adds security descriptor attribute to file systemData in file considered to be attribute of file Allows fast access to files Eliminates file fragmentation

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  • Structure of a Disk Master File Table (MFT)MFT:Attribute stored in MFT considered resident attributeAny resident forced out to an extent is nonresident attribute

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  • Structure of a Disk Master File Table (MFT)Folders treated as files in NTFS:Small folder - Index Root attributeFolder entries will fit into MFT - new extent nonresident attribute called index buffer

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  • Structure of a Disk Deciding on a File SystemFormatting:Floppy disk - always FAT file systemHard disk - you decide

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  • Structure of a Disk Deciding on a File System Can convert FAT to FAT32/NTFS

    Cannot convert FAT32/NTFS to FAT

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  • Clarifying Procedures

    Procedural assumptions: System utility files subdirectory Type of disk Lab procedures

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  • ActivityFormatting a Floppy Disk

    KEY CONCEPTS: Function of screen prompt Internal vs. external commands Result of keying in FORMAT C: Using the FORMAT commandUnique serial number used for disk identification by application programs.

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  • Formatting a Disk with a Volume Label

    FORM