One of the most important issues with whicheach owner of the computer is confronted with the following: “How to organize reliable storage of digital data?”. Although modern information carriers are presented in a wide range, often the cost of many of them turns out to be too high for both enterprises and home users. However, there is a solution. It is necessary to study what types of information carriers there are and, taking into account the needs, to choose the best option for the “cost / characteristics” parameter. And you need to take into account the durability of data integrity.
Let's start with the definition.A storage medium in computing is an object that has the ability in one way or another to save the coded electronic oscillations transmitted to it, as well as to provide the possibility of their re-reading (reproduction) in its original form. Key features are as follows:
- the possibility (or impossibility) of re-recording;
- The principle of information preservation used
- constructive differences and total cost.
The most common storage medium incomputers is a hard disk (hard drive, HDD). Its use makes it possible to create a high-speed storage of digital data and provide constant access to it.
Inside a rectangular metal casethere are several high-speed rotating glass or plastic disks coated with magnetic sputtering. When recording, special heads magnetize the surface in a certain way, and when reading, they pick up these changes in the magnetic field and convert them into electrical signals, in fact, receiving binary digits — data. Currently, this storage medium is actively evolving, as manufacturers are increasingly offering options for hard drives with a completely different storage principle - based on flash memory. In the mass market segment, the interface for connecting these devices to a computer is Serial ATA and USB. The advantages of HDD are low cost in terms of gigabytes, high reliability and performance, versatility.
The next storage medium is optical.disk. The principle of recording is based on the creation by the laser beam of depressions in the supporting metal layer, from the outside of which there is a reflective deposition (substrate). With the reading command, the beam is positioned on the desired tracks (tracks), reflected from the substrate, focused by the lens and recorded by the photocell. Since the intensity of the process directly depends on the state of the surface, this allows one to obtain electrical binary discharges, that is, to read the recorded information.
Depending on the characteristics of the beam usedThere are various kinds of CDs and devices for reading them (drives): CDs with 740 MB of available capacity, DVDs with 4.7 GB and Blu-Ray with 25 GB and more. A quality disk with careful handling can save information for several decades, as it is not exposed to magnetic fields. You can read more about CD technology on the Internet.
One of the most promising areas instorage media is flash memory technology. Famous flash drives in mobile phones - these are the very devices. Computers use other external interfaces - USB and SATA. Winchesters with such a memory are called solid-state. The implementation is quite simple: in all such devices, a flash memory chip is installed, the cells of which, unlike the usual memory modules, are able to keep their state unchanged for up to 10 years. During operation, electricity consumption is negligible, since there are no moving parts, and reliability is maximum. Technology is constantly being improved.
There are also backup devices based on magnetic tape (the principle of operation is similar to old tape cassettes). Capacity reaches 3 TB.
