ch 3 disks and formattingfaculty.skagit.edu/imageuploads/repository592.pdf · 2010-08-29 · ch 3...

Ch 3 1

Disks andFormatting

Ch 3 2

Overview

The need for formatting a disk will be discussed.

Ch 3 3

Overview

The difference between partitioning and formatting a

disk will be explained.

Ch 3 4

Overview

The structure of a disk will be described.

Ch 3 5

Overview

Will learn to format a disk, electronically label it, and

then how to change the label.

Ch 3 6

Overview

Various file systems will be compared and contrasted.

Ch 3 7

Overview

Some of the parameters that can be used with the FORMAT

command will be discussed and then used with the FORMAT

command.

Ch 3 8

Why Format a Disk?

Disks used for:

Permanent storage of data and programs

Distributing data from one computer to another

Making copies

Ch 3 9

Why Format a Disk?

Formatting (initializing) the disk:

Process of preparing disk so that it is compatible with an operating system

Ch 3 10

Why Format a Disk?

All disks (including hard disks) must be formatted.

Ch 3 11

Partitioning and Formatting Disks

Hard disks must be:

Partitioned

Formatted with file system

Ch 3 12


Partition terms:

Primary partition

Partition table

Volume

Active partition

Extended partition

Ch 3 13


Dual booting system:Create partition for each OS

Only one OS active at a time

Each OS formats disks in own way

Precautions in running multiple OS

Ch 3 14


File system:Organizational scheme of OSOS is what makes one computer compatible with another

Ch 3 15


Windows XP Professional supports four file systems:

NTFS

Three FAT file systems -FAT12

FAT16

FAT32

Ch 3 16


Types of disk storage configuration: Basic disks

Dynamic disks

Ch 3 17

Structure of a Disk

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

High level (logical) formatting

Ch 3 18

Structure of a Disk

Low-level (physical) formatting:Sequentially numbers tracks and

sectors

Identifies each track and sector

Disk is physically prepared to hold data

Ch 3 19

Structure of a Disk

High-level (logical) formatting:Determines how OS uses a disk

Builds structure to keep track of location of files

Done so files can be stored and retrieved.

Ch 3 20

Structure of a Disk

Windows XP Professional monitors status of all disk data sectors.

Ch 3 21

Structure of a Disk

One or more sectors are combined into logical units called clusters or allocation

units.

Ch 3 22

Structure of a Disk

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

with

Ch 3 23

Structure of a Disk

Cluster overhang:

Wasted space on the disk.

Ch 3 24

Structure of a Disk Master Boot Record & Boot Sector

Master boot record (MBR):

First part of hard disk

Locates bootable partition of hard

disk and gives control over to it

Ch 3 25

Structure of a DiskMaster Boot Record & Boot Sector

Boot sector:

First sector on logical drive

Has table of drive’s characteristics

Has bootstrap loader program

Ch 3 26


All disks (including non-system

disks) have a boot sector.

Ch 3 27


FAT non-system error messages:

Non-system disk or disk error

Replace disk and press any key

when ready

Ch 3 28


NTFS non-system error messages:

Invalid partition table

Error loading operating system

Missing operating system

Ch 3 29


Floppy disk non-system error messages:

NTLDR is missing

Press any key to restart

Ch 3 30


Windows uses boot sector to identify the type of disk.

Ch 3 31

Structure of a DiskFAT16, VFAT & FAT32

FAT’s formatting program creates: Boot record

File Allocation Table (2 copies)

Root directory

Ch 3 32


Fig 3.1 Logical Structure of a Disk p. 100

Ch 3 33


FAT is a map of disk’s data clusters.

FAT number indicates status of cluster. Numbers in FAT link clusters that

belong to same file

Ch 3 34


Table 3.1 Cluster Size and Disk Size p. 100

Ch 3 35


FAT essential for:Managing data

Following trail of clusters that make up a file

Ch 3 36


VFAT maintains backwards compatibility and

accommodates long file names.

Ch 3 37


FAT32:

Enhancement of FAT file system

Introduced to overcome limitations of VFAT

Does not apply to floppy drives

Ch 3 38


Table 3.2 Comparison of FAT and FAT32 p. 101

Ch 3 39


FAT32:Movable Root Directory

Can be located anywhere on hard disk

Can use backup copy of FAT

Internal backup copy of some critical FAT data structures

Entries in Root Directory limited

Ch 3 40


With smaller clusters:

More clusters on partition

FAT larger - store more data

Takes longer to locate/access file

Ch 3 41


With larger clusters:

Table smaller

Takes less time to locate/access file

Increases wasted disk space from cluster overhang

Ch 3 42


FAT32 is best for many small files.

FAT is best for mostly large files.

Ch 3 43

Structure of a DiskThe Root Directory

Root Directory:Table that records information

about each file on the disk

Ch 3 44

Structure of a DiskThe Root Directory

Changes in root directory table make Windows XP Professional compatible with older Windows

and DOS programs.

Ch 3 45

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.

Ch 3 46

Structure of a DiskFAT 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.

Ch 3 47

Structure of a DiskFAT and the Root Directory

Fig 3.2 The Root Directory and FAT p. 103

Ch 3 48

Structure of a DiskData Portion or the Files Area

Largest part of disk is used for

storing files.

Space is allocated to files on an as-

needed basis.

Ch 3 49

Structure of a DiskData Portion or the Files Area

A file is written to a disk in:

Contiguous clusters or

Noncontiguous clusters.

Ch 3 50

Structure of a DiskUnderstanding FAT & Root

Directory TableFig 3.3 Storing Files p. 105

Ch 3 51

Structure of a DiskNTFS

File system used determines OS advanced features available to user.

For disk security, performance, and

efficiency use NTFS file system.

Ch 3 52

Structure of a DiskNTFS

Advantages of NTFS: Secure file system

Efficient storage of data

Faster file access

Better data recovery

Can compress files/assign disk quotas

Encryption of files

Ch 3 53

Structure of a Disk Clusters and NTFS

NTFS:

Uses FAT cluster scheme for allocating data.

Has less overhead.

Ch 3 54

Structure of a DiskClusters and NTFS

Table 3.3 NTFS Cluster Size p. 106

Ch 3 55

Structure of a DiskClusters and NTFS

Fig 3.4 Structure of an NTFS Volume p. 106

Ch 3 56

Structure of a DiskMaster File Table (MFT)

Master File Table (MFT):

Database of all files in system

Used by NTFS to track all files

and directories in a volume

Dynamic

Ch 3 57


MFT is different from FAT.

Ch 3 58


MFT:Adds security descriptor attribute to

file system

Data in file considered to be attribute of file

Allows fast access to files

Eliminates file fragmentation

Ch 3 59


MFT:

Attribute stored in MFT considered

resident attribute

Any resident forced out to an extent is

nonresident attribute

Ch 3 60


Folders treated as files in NTFS:Small folder - Index Root attribute

Folder entries will fit into MFT -new extent nonresident attribute called index buffer

Ch 3 61

Structure of a DiskDeciding on a File System

Formatting:

Floppy disk - always FAT file system

Hard disk - you decide

Ch 3 62

Structure of a DiskDeciding on a File System

Can convert FAT to FAT32/NTFS

Cannot convert FAT32/NTFS to

FAT

Ch 3 63

Clarifying Procedures

Procedural assumptions: System utility files subdirectory

Type of disk

Lab procedures

Ch 3 64

Activity—Formatting a Floppy Disk

KEY CONCEPTS:

Function of screen prompt

Internal vs. external commands

Result of keying in FORMAT C:

Using the FORMAT command

Unique serial number used for disk

identification by application programs.

Ch 3 65

Formatting a Disk with a Volume Label

FORMAT command parameters:

FORMAT volume [/FS:file-system]

[/V:label] [/Q] [A:size] [/C] [/X]

FORMAT volume [/V:label] [/Q]

[/F:size]

Ch 3 66


FORMAT command parameters:


[/T:tracks /N:sectors]


FORMAT volume [/Q]

Ch 3 67


Basic syntax of FORMAT command:


Ch 3 68


/F size parameter:

Easy way to format floppy disks that do not match capacity of a floppy disk drive

Ch 3 69


Volume label is electronic name.

Partial command diagram FORMAT A: /V[:label]

No spaces between colon and label

Ch 3 70

Activity—Using the /V Option

KEY CONCEPTS:

Purpose/function of VOL command

Need of descriptive volume label

Two ways to display volume label

[drive:] - variable parameter

Ch 3 71

The LABEL Command

LABEL command:

External command

Used to change volume label

without reformatting disk

Ch 3 72

The LABEL Command

Partial syntax:

LABEL [drive:] [label]

Ch 3 73

The LABEL Command

LABEL (external) command:

Used to change volume label

VOLUME (internal) command:

Used to see volume label

Ch 3 74

Activity—Using the Label Command

KEY CONCEPTS:

Importance of including A: parameter

Deleting volume label on disk

Placing volume label on disk

Use of spaces in LABEL and

VOLUME commands

Ch 3 75

Formatting a Disk using the /Q Parameter

/Q parameter: Fast way to clear previously

formatted disks

Works like usual FORMAT commandSkips low level formatting

Clears FAT and root directory

Does not check for bad sectors

Ch 3 76

Activity—Using the /Q Parameter

KEY CONCEPTS:

Reason /Q parameter can be used

Eliminate previous volume label when

formatting disk

ch 3 disks and formattingfaculty.skagit.edu/imageuploads/repository592.pdf · 2010-08-29 · ch 3...

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