Transcript Disks and Formatting Ch 3 Overview The need for formatting a disk will be discussed. Ch 3

Disks and
Formatting
Ch 3
1
Overview
The need for formatting
a disk will be discussed.
Ch 3
2
Overview
The difference between
partitioning and formatting a
disk will be explained.
Ch 3
3
Overview
The structure of a
disk will be described.
Ch 3
4
Overview
Will learn to format a disk,
electronically label it, and
then how to change the label.
Ch 3
5
Overview
Various file systems will be
compared and contrasted.
Ch 3
6
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
7
Why Format a Disk?
Disks used for:
Permanent storage of data and
programs
Distributing data from one
computer to another
 Making copies
Ch 3
8
Why Format a Disk?
Formatting (initializing) the disk:
 Process of preparing disk so that it
is compatible with an operating
system
Ch 3
9
Why Format a Disk?
All disks (including hard
disks) must be formatted.
Ch 3
10
Partitioning and
Formatting Disks
Hard disks must be:
 Partitioned
 Formatted with file system
Ch 3
11
Partitioning and
Formatting Disks
Partition terms:
 Primary partition
 Partition table
 Volume
 Active partition
 Extended partition
Ch 3
12
Partitioning and
Formatting Disks
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
13
Partitioning and
Formatting Disks
File system:
 Organizational scheme of OS
OS is what makes one computer
compatible with another
Ch 3
14
Partitioning and
Formatting Disks
Windows XP Professional supports
four file systems:
 NTFS
 Three FAT file systems FAT12
 FAT16
 FAT32
Ch 3
15
Partitioning and
Formatting Disks
Types of disk storage configuration:
 Basic disks
 Dynamic disks
Ch 3
16
Structure of a Disk
Two parts to formatting a disk:
 Low-level (physical) formatting
 High level (logical) formatting
Ch 3
17
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
18
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
19
Structure of a Disk
Windows XP Professional
monitors status of all
disk data sectors.
Ch 3
20
Structure of a Disk
One or more sectors are
combined into logical units
called clusters or allocation
units.
Ch 3
21
Structure of a Disk
Cluster (allocation unit):
 Smallest unit that OS can work
with
Ch 3
22
Structure of a Disk
Cluster overhang:
 Wasted space on the disk.
Ch 3
23
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
24
Structure of a Disk
Master Boot Record & Boot Sector
Boot sector:
 First sector on logical drive
 Has table of drive’s characteristics
 Has bootstrap loader program
Ch 3
25
Structure of a Disk
Master Boot Record & Boot Sector
All disks (including non-system
disks) have a boot sector.
Ch 3
26
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
Ch 3
27
Structure of a Disk
Master Boot Record & Boot Sector
NTFS non-system error messages:
 Invalid partition table
 Error loading operating system
 Missing operating system
Ch 3
28
Structure of a Disk
Master Boot Record & Boot Sector
Floppy disk non-system error messages:
 NTLDR is missing
 Press any key to restart
Ch 3
29
Structure of a Disk
Master Boot Record & Boot Sector
Windows uses boot sector to
identify the type of disk.
Ch 3
30
Structure of a Disk
FAT16, VFAT & FAT32
FAT’s formatting program creates:
 Boot record
 File Allocation Table (2 copies)
 Root directory
Ch 3
31
Structure of a Disk
FAT16, VFAT & FAT32
Fig 3.1 Logical Structure of a Disk p. 100
Ch 3
32
Structure of a Disk
FAT16, VFAT & FAT32
 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
33
Structure of a Disk
FAT16, VFAT & FAT32
Table 3.1 Cluster Size and Disk Size p. 100
Ch 3
34
Structure of a Disk
FAT16, VFAT & FAT32
FAT essential for:
 Managing data
 Following trail of clusters that
make up a file
Ch 3
35
Structure of a Disk
FAT16, VFAT & FAT32
VFAT maintains
backwards compatibility and
accommodates long file names.
Ch 3
36
Structure of a Disk
FAT16, VFAT & FAT32
FAT32:
 Enhancement of FAT file system
 Introduced to overcome
limitations of VFAT
 Does not apply to floppy drives
Ch 3
37
Structure of a Disk
FAT16, VFAT & FAT32
Table 3.2 Comparison of FAT and FAT32 p. 101
Ch 3
38
Structure of a Disk
FAT16, VFAT & FAT32
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
39
Structure of a Disk
FAT16, VFAT & FAT32
With smaller clusters:
 More clusters on partition
 FAT larger - store more data
 Takes longer to locate/access file
Ch 3
40
Structure of a Disk
FAT16, VFAT & FAT32
With larger clusters:
 Table smaller
 Takes less time to locate/access file
 Increases wasted disk space from
cluster overhang
Ch 3
41
Structure of a Disk
FAT16, VFAT & FAT32
 FAT32 is best for many small files.
 FAT is best for mostly large files.
Ch 3
42
Structure of a Disk
The Root Directory
Root Directory:
 Table that records information
about each file on the disk
Ch 3
43
Structure of a Disk
The Root Directory
Changes in root directory table
make Windows XP Professional
compatible with older Windows
and DOS programs.
Ch 3
44
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
45
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.
Ch 3
46
Structure of a Disk
FAT and the Root Directory
Fig 3.2 The Root Directory and FAT p. 103
Ch 3
47
Structure of a Disk
Data 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
48
Structure of a Disk
Data Portion or the Files Area
A file is written to a disk in:
 Contiguous clusters or
 Noncontiguous clusters.
Ch 3
49
Structure of a Disk
Understanding FAT & Root
Directory Table
Fig 3.3 Storing Files p. 105
Ch 3
50
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.
Ch 3
51
Structure of a Disk
NTFS
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
52
Structure of a Disk
Clusters and NTFS
NTFS:
Uses FAT cluster scheme for
allocating data.
Has less overhead.
Ch 3
53
Structure of a Disk
Clusters and NTFS
Table 3.3 NTFS Cluster Size p. 106
Ch 3
54
Structure of a Disk
Clusters and NTFS
Fig 3.4 Structure of an NTFS Volume p. 106
Ch 3
55
Structure of a Disk
Master 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
56
Structure of a Disk
Master File Table (MFT)
MFT is different from FAT.
Ch 3
57
Structure of a Disk
Master File Table (MFT)
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
58
Structure of a Disk
Master File Table (MFT)
MFT:
 Attribute stored in MFT considered
resident attribute
 Any resident forced out to an extent is
nonresident attribute
Ch 3
59
Structure of a Disk
Master File Table (MFT)
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
60
Structure of a Disk
Deciding on a File System
Formatting:
 Floppy disk - always FAT file
system
 Hard disk - you decide
Ch 3
61
Structure of a Disk
Deciding on a File System
 Can convert FAT to FAT32/NTFS
 Cannot convert FAT32/NTFS to
FAT
Ch 3
62
Clarifying Procedures
Procedural assumptions:
 System utility files subdirectory
 Type of disk
 Lab procedures
Ch 3
63
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
64
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
65
Formatting a Disk with a
Volume Label
FORMAT command parameters:
 FORMAT volume [/V:label] [/Q]
[/T:tracks /N:sectors]
 FORMAT volume [/V:label] [/Q]
 FORMAT volume [/Q]
Ch 3
66
Formatting a Disk with a
Volume Label
Basic syntax of FORMAT command:
FORMAT volume [/V:label] [/Q]
Ch 3
67
Formatting a Disk with a
Volume Label
/F size parameter:
 Easy way to format floppy disks that
do not match capacity of a floppy disk
drive
Ch 3
68
Formatting a Disk with a
Volume Label
 Volume label is electronic name.
 Partial command diagram
FORMAT A: /V[:label]
 No spaces between colon and label
Ch 3
69
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
70
The LABEL Command
LABEL command:
 External command
 Used to change volume label
without reformatting disk
Ch 3
71
The LABEL Command
Partial syntax:
 LABEL [drive:] [label]
Ch 3
72
The LABEL Command
LABEL (external) command:
 Used to change volume label
VOLUME (internal) command:
 Used to see volume label
Ch 3
73
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
74
Formatting a Disk using
the /Q Parameter
/Q parameter:
 Fast way to clear previously
formatted disks
 Works like usual FORMAT
command
Skips low level formatting
 Clears FAT and root directory
 Does not check for bad sectors
Ch 3
75
Activity—Using the /Q
Parameter
KEY CONCEPTS:
 Reason /Q parameter can be used
 Eliminate previous volume label when
formatting disk
Ch 3
76