Hard Disk Drive

The computer stores information that is permanent, on the Hard Disk platter. The Hard Disk is sealed in the Hard Disk Drive. The disc is made from aluminium with coating of magnetic material such as ferric oxide or chromium oxide. The Hard Disk Drive is very sensitive to shock and electrostatic discharge.

General

Data is stored on the surface of a platter in sectors and tracks. Tracks are concentric circles, and sectors are pie-shaped wedges on a track with magnetic marking and an ID number, Sectors have a sector header and an error correction code (ECC). In modern drives, sectors are numbered sequentially. A sector contains a fixed number of bytes -for example, 256 or 512. Either at the drive or the operating system level, sectors are often grouped together into clusters.

The process of low-level formatting a drive establishes the tracks and sectors on the platter. The starting and ending points of each sector are written onto the platter. This process prepares the drive to hold blocks of bytes. High-level formatting then writes the file-storage structures, like the file-allocation table, into the sectors. This process prepares the drive to hold files.

Cylinder: A group of tracks with the same radius is called a cylinder.
Data addressing: There are to methods for Drive's data addressing: CHS (cylinder-head-sector) and LBA (logical block address). CHS is used on most IDE drives, while LBA is used on SCSI and Enhanced IDE (EIDE) drives.
Cluster: In a computer system, a cluster is a group of servers and other resources that act like a single system and enable high availability and, in some cases, load balancing and parallel processing. In personal computer storage technology, a cluster is the logical unit of file storage on a hard disk; it's managed by the computer's operating system. Any file stored on a hard disk takes up one or more clusters of storage. A file's clusters can be scattered among different locations on the hard disk.

Installation

Turn off the computer, unplug the external cables, and open computer cover. Mount the Hard Disc in the designated place in the computer.
Connect 40 pin interface cable and power cable. Make sure that the directions of the cables are correct and match the shape of the receptacles when connecting cables. Incorrect cable connection may damage the Hard Disk Drive.
Making Computer Detect the new Device. Run the CMOS (BIOS) set-up program to detect the new Hard Disk Drive.
- Open the CMOS setup during the booting of the computer.
- Let the computer detect the Hard Disk.
- Save the changes and exit.

Partitioning and formatting the Drive.

There are two types of formatting: High Level and Low Level.

High Level Formatting: It is a formatting method that initializes portions of the hard disk and creates the file system structures on the disk, such as the master boot record and the file allocation tables. High-level formatting prepares drive partitions for the operating system by creating a root directory, from which all other subdirectories could be created, and creating a File Allocation Table (FAT), which keeps track of all information on the disks and all the relationships between different pieces of information.
Low Level Formatting: It is a formatting method that creates the tracks and sectors on a hard disk. Low-level formatting creates the physical format that dictates where data is stored on the disk. At this stage, the drive is being physically divided into tracks and sectors. Low-level formatting stays unchanged for the entire life of the drive unless the drive is re-formatted. A low-level format is also called a physical format.

The following is the steps for formatting the Hard Disk.

For partitioning and formatting the drive, one can use the DOS 'FDISK' command.
The following text will appear on the screen. Press 'Y' to enable large disk support or 'N' to disable and press Enter key.
On the next screen, there are four option displayed. Each of which is self explaining.

Create partitions: FDISK allows creating a primary DOS partition or logical DOS volumes. To create a logical DOS volume you must of course first create an extended DOS partition, since the logical are contained within the extended partition.
Set active partition: This sets the primary boot partition on disk, and is called boot drive.
Delete a partition: This will delete partitions. This is the only way to change the size of a partition using FDISK.
Display the partition information: This will first show the primary and extended partitions and then ask to see the logical drives within the extended partition.

These steps will create partition on the Hard Disk and format it, but it takes some time. Formatting can also be done from windows by selecting the drive and selecting the 'format' command from file menu. There are many tools available that reduce the partitioning and formatting time.

Troubleshooting

Mostly there are only software level problems occur with the hard disk such as hard disk is not detected by the computer. This problem can be removed using the following procuder.

A message appears 'system boot failure, press any key when ready'.

Go the BIOS setup and auto detects the hard disk.
Load BIOS default settings.
Restart the computer and the computer will start normally.
If still message appears then check the both the power and data cable of hard disk.
Make a bootable floppy and boot the system and then transfer the system to the hard disk by typing 'sys c:' on the command prompt.

If there are some bad sectors on the hard disk, use the scan disk tool of windows to lock the bad sectors area.