Presantation1.1.pptx.pdfffffffffffffffff

Sahil mahato

1. HARD DISK DRIVE A Hard Disk Drive is a secondary storage device used to store large amount of data permanently that means data is retained when the computer is turned off. It is also called Hard Disk, Hard Drive and fixed disk. It was invented by IBM team by Rey Johnson. There are different parts inside the hard disk such as platter, head, actuator arm, spindle motor etc. The platters are paired with magnetic head usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Spindle motor is used to rotate for the platter media.

2. Types of Hard Disk Parallel Advanced Technology Attachment ( PATA/ATA/IDE) SATA Small Computer System Interface (SCSI) Solid State Drives (SSD)

3. COMPONENTS

4. Construction of HDD The hard disk uses a rigid platter. One or more platters are mounted on a common spindle. A platter has two magnetic surfaces, top and bottom. It consists of a spindle motor to drive the above mentioned  stack of platters about its axis at a  speed ranging from  3600 rpm to 72 00 rpm. A set of magnetic heads made up of thin magnetic film which perform the operation of accessing the information from the platters. Information is recorded on both the sides of the disk.

5. operation The outer surface of top and bottom disk cannot be used for storing information as they can’t be accessed. Information is recorded on the  circular tracks  and the  track  is divided into  sectors . The capacity of the hard disk depends upon the total number of usable surface, bytes stored per sector, sectors per track, tracks per surface. Capacity of HD=[no. of usable surface] X [bytes stored per sec] X [sectors per track] X [track per surface].

6. Hard Disk Geometry Hard disk drives are composed of one or more disks or platters on which data is stored. The geometry of a hard drive is the organization of data on these platters. Geometry determines how and where data is stored on the surface of each platter. Disk Geometry refers to the electronic organization of any type of disk drive the actual physical number of heads, cylinders, tracks and sectors. 

7. Tracks A disk drive Track  is a circular path on the surface of a disk on which information is magnetically recorded and from which recorded information is read. Each track can hold a large amount of data counting to thousands of bytes.

8. Sectors Each track is further broken down into smaller units called sectors. As sector is the basic unit of data storage on a hard disk. A single track typically can have thousands of sectors and each sector can hold more than 512 bytes of data.

9. Cylinder A  cylinder  is any set of all of tracks of equal diameter in a hard disk drive (HDD). It can be visualized as a single, circle that cuts through all of the platters in both sides in the drive.