Disk Hardware in Operating System

This post on disc hardware provides a brief description of the following types of disc hardware:

Magnetic disks
RAID
CD-ROM
CD-Recordable
CD-Rewritable
DVD

Magnetic Disks

The magnetic discs are organized into cylinders, and each cylinder has a number of tracks equal to the number of heads that are stacked vertically above it. And the tracks are separated into their respective sectors.

RAID

"Redundant Array of Inexpensive Disks" is what "RAID" stands for in its full name. Installing a box full of discs next to the computer, which is typically a large server, then replacing the disc controller card with a RAID controller, copying the data over to the RAID, and then continuing with the normal operation is the fundamental concept behind the technology known as RAID, which stands for redundant array of inexpensive discs.

In other words, you could say that RAID appears to the operating system to be an SLED, which stands for "single large expensive disc." However, RAID outperforms SLED both in terms of performance and reliability.

CD-ROM

In the year 1980, two major companies, namely Philips and Sony, collaborated on the development of the compact disc (CD), which quickly replaced the 33 1/3 rpm vinyl record as the primary medium for storing and playing music.

All of the compact discs have a diameter of 120 millimetres, a thickness of 1.2 millimetres, and a hole measuring 15 millimetres in the centre of the disc.

Now, almost four years later, in the year 1984, these two companies realised the power and potential of using compact discs to store computer data; as a result, they developed CD-ROM, which stands for Compact Disk-Read Only Memory. CD-ROM is an abbreviation for "Compact Disk-Read Only Memory."

CD-Recordable

Physically, CD-Recordable (CD-R) stars are similar to CD-ROMs in that they are made of 120mm polycarbonate blanks; however, unlike CD-ROMs, CD-R stars contain a groove that is 0.6mm wide to direct the laser during the writing process.

CD-Rewritable

CD-ReWritable (CD-RW) is a technology that was developed in response to public demand for a rewritable CD-ROM. This technology uses media of the same size as CD-Recordable (CD-R), and it was given the acronym CD-RW (CD-R).

However, the recording layer of a CD-RW is made from an alloy that consists of silver, antimony, indium, and tellurium.

DVD

DVD stands for "digital video disc" or "digital versatile disc." The general layout of a DVD is comparable to that of a CD; both formats make use of injection-molded polycarbonate discs measuring 120 millimetres in diameter and containing pits and lands that are illuminated by a laser diode and read by a photodetector.