|
|
|
Introduction to hard drives |
|
|
|
|
Identify various types of hard drives and
understand technology and advantages of each |
|
Describe how data is stored on a hard drive |
|
Manage a hard drive to by using DOS and Windows
commands |
|
Optimize hard drive performance by using the
System Tools utilities |
|
|
|
|
|
|
|
|
|
Methods used to adjust for smaller tracks closer
to center of platter |
|
Write precompensation |
|
Reduced write current |
|
|
|
|
|
A hard drive whose disk controller is integrated
into the drive |
|
Eliminates need for controller cable |
|
Increases speed |
|
Reduces price |
|
Most system boards provide one or two IDE
connections directly on system board |
|
|
|
|
|
|
|
Use either 17 or 26 sectors per track |
|
Wastes drive space |
|
Number of bytes a track can hold is determined
by centermost track |
|
|
|
|
|
Use zone bit recording |
|
Tracks near center have smallest number of
sectors per track |
|
Number of sectors increases as tracks get larger |
|
Have 512 bytes per sector for every sector on
the drive |
|
|
|
|
|
|
Provides a standard for communication between a
subsystem of peripheral devices and the system bus |
|
Most SCSI drives are IDE drives |
|
|
|
|
|
|
|
General categories |
|
Narrow (8 bits) |
|
Wide (16 bits) |
|
Ways a SCSI cable can be built |
|
Single-ended |
|
Differential |
|
Three major standards |
|
SCSI-1 (Regular SCSI) |
|
SCSI-2 (Fast SCSI) |
|
SCSI-3 (Ultra SCSI) |
|
|
|
|
|
|
|
|
|
Termination |
|
Several ways to terminate power |
|
Types of terminators: passive, active, forced perfect |
|
Device drivers |
|
Advanced SCSI Programming Interface (ASPI) |
|
Common Access Method (CAM) |
|
Host adapter issues |
|
Compare installation procedures and options |
|
|
|
|
|
|
|
|
|
Steps in preparing a hard drive to hold data |
|
Low-level format |
|
Partitioning the hard drive |
|
High-level format |
|
|
|
|
|
|
|
|
|
|
|
A portion or all of a hard drive partition that
is treated by the operating system as though it were a physical drive
containing: |
|
Boot record |
|
FAT |
|
Root directory |
|
|
|
|
|
|
|
|
The OS uses the FAT and a directory to keep
track of which clusters are being used for a particular file, together with
other information about the file |
|
To the OS, each logical drive is treated like a
single floppy disk: a physical
drive divided into three logical drives is equivalent to three separate
physical drives |
|
|
|
|
|
|
|
|
|
Virtual file allocation (VFAT) |
|
An improved method of hard drive access that
allows for long filenames and 32-bit access |
|
FAT32 |
|
Allows better management of very large hard
drives |
|
The root directory |
|
Layout is the same as for floppy disks |
|
|
|
|
DOS commands |
|
Windows 3.x |
|
Windows 9x |
|
|
|
|
|
MKDIR or MD |
|
Creates a subdirectory entry in a directory |
|
CHDIR or CD |
|
Changes the current default directory |
|
RMDIR or RD |
|
Removes a directory |
|
|
|
|
|
|
|
|
|
TREE |
|
Displays directory structure of a hard drive or
disk |
|
ATTRIB |
|
Displays or changes the read-only, archive,
system, and hidden attributes assigned to a file |
|
|
|
|
|
PATH |
|
Lists where DOS and Windows 3.x should look to
find executable program files |
|
Batch files |
|
Series of
DOS commands that will execute |
|
|
|
|
|
Primary tool:
File Manager |
|
Create directory |
|
Delete a directory |
|
File properties |
|
Batch files |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Primary tool:
Windows 9x Explorer |
|
Create a new folder |
|
Delete a folder |
|
File properties |
|
|
|
|
|
|
|
|
|
|
|
|
Fragmentation |
|
Cross-linked and lost clusters |
|
Disk compression |
|
Disk caching |
|
|
|
|
|
|
Distribution of data files in noncontiguous
clusters; increases data access time |
|
Routine maintenance: defragment the hard drive |
|
DOS |
|
DOS 6+ DEFRAG or a utility software package |
|
Windows 98 |
|
Defragmenter utility |
|
|
|
|
|
|
|
|
|
Cross-linked |
|
More than one file points to them |
|
Lost |
|
No file in the FAT points to them |
|
To repair:
use ScanDisk utility in either DOS or Windows 9x |
|
|
|
|
|
|
|
|
|
|
|
|
|
Compresses data on a hard drive to allow more
data to be written to the drive |
|
Works by |
|
Storing data on the hard drive in one big file
and managing the writing of data and programs to that file |
|
Rewriting data in files in a mathematically
coded format that uses less space |
|
|
|
|
Host drive |
|
Compressed volume file (CVF) |
|
|
|
|
|
Uses DriveSpace to: |
|
Assign different drive letter to hard drive,
(e.g., H) |
|
Compress entire contents of hard drive into a
single file on drive H |
|
Set up the drive so that Windows 9x and other
applications view this compressed file as drive C |
|
Configure Windows 9x so that each time it boots,
DriveSpace driver will load and manage the compressed drive |
|
|
|
|
|
A method whereby recently retrieved data and
adjacent data are read into memory in advance, anticipating the next CPU
request |
|
Two kinds of hard drive caches |
|
Hardware cache |
|
Software cache |
|
|
|
|
|
|
|
Disk cache in DOS and Windows 3.x |
|
SMARTDrive |
|
Other packages (e.g., Norton Cache, Mace Cache,
Super PC-Kwik Cache) |
|
VCACHE in Windows 9x |
|
DOS buffers |
|
An area in memory where data waiting to be read
or written is temporarily stored |
|
|
|
|
Don’t use disk utility software that does not
know about VFAT, long filenames or FAT32 |
|
Don’t use FDISK, FORMAT C:, SYS C:, or CHKDSK
while in a DOS session |
|
Don’t optimize or defragment the hard drive
using software that does not know about long filenames |
|
|
|
|
Don’t run hard drive cache programs unless
written especially for Windows 95 or Windows 98 |
|
Don’t use older DOS backup programs (BACKYUP,
MSBACKUP) |
|
|
|
|
|
Compared hard drive technologies |
|
IDE |
|
SCSI |
|
Partitioned a hard drive |
|
Identified OS commands for managing hard drives |
|
Discussed optimizing hard drives |
|
Notes
