As of this writing, hard disks drives are still the major secondary storage device for desktop computers as well as some other laptop brands as well as servers.
Hard drive is just one of the major computer components. It is part of a computer’s memory sector. It’s major operation is to retain and save files and programs for later use.
One of hard disk’s physical structures are thin but rigid metal, glass, or ceramic platters covered with a substance that allows data to be held in the form of magnetized spots. Most hard desk drives may consist of two precisely positioned platters – the greater the number of platters, the larger the capacity of the drive. The platters in the drive are separated by spaces and are clamped to a rotating spindle that turns all disk-drive unit to prevent any foreign matter from getting inside. Data maybe recorded in both sides of the platters.
On the disk, data is recorded in concentric recording band called Tracks. Unlike on a vinyl phonograph record, these tracks are neither visible grooves nor a single spiral. Rather, they are closed concentric rings; each tract forms a s full circle on the disk. When a disk is formatted, the disk’s storage locations are divided into wedge-shaped sections, which break the tracks into small arcs called Sectors. When you save data from your computer to a disk, the data is distributed by tracks and sectors on the disks. The smallest unit of disk drive that will be able to be written or read is called a Cluster. A Cluster is a group of sectors on a storage device.
Hard disks are sensitive devices. The read/write head does not touches the desk entirely but rather rides on a cushion of air about 0.000001 thick. The disk is sealed from impurities within a container, and the whole apparatus is fabricated under a very clean conditions. Else, all it would take is a dust particle, a fingerprint smudge, or a smoke particle to cause what is called a head crash. This head crash happens when the read and write head comes into a close contact with the platter.
A head crash may also happen when a HDD gets a hard bump on hard objects such as when a CPU or a laptop is dropped. The common consequence of mishandling or a bump are lose of data and an inoperable hard drive.
Fortunately, their are lots of company who offers Data Retrieval over an ill-fated hard drive, but up to certain extend only and for a hefty price.
Read More: How Hard Drive Works?