Each user has information that they would like to save on long time. Photos, videos, audio or important documents. However, just write them down hard drive and not touching is not enough. Gradually, the drive wears out, and you shouldn’t forget about failures or damage. This article will describe how to properly store information for better safety.
General principles for secure information storage
- Must be done several copies. It is better to write really important files onto several devices or drives, which will make it more likely that at least one media will be saved in case of unforeseen circumstances.
- It is better to store data in widely distributed and known formats. If this text document, then it's better to save it in txt format than in some exotic one. The likelihood that in ten years there will be programs capable of opening the most common format is much higher than if it is a file that only a couple of utilities can run.
- The more targeted the data, the better. It's not worth encrypting, archive or compress data. If a regular file is slightly damaged, there is a good chance of it running, but if an archived or encrypted file is damaged, the chances are small.
- Also don't forget check your details from time to time, if the media is many years old or there are doubts about its integrity, then it would be better to resave the information to new drive, it's also a good idea to try new devices and recording types.
Using Traditional Drives
This section will describe standard storage options and the advantages and disadvantages of each.
- CD, DVD, Blu-Ray theoretically, these drives can be stored for a very long time, as well as the information on them. However, there are many nuances here, so this method will be discussed in more detail below.
- Cloud storage. They can store data indefinitely. This is in an ideal world. In fact, they will be there as long as it is profitable for the companies and brings them benefits. Moreover, judging by license agreements, they do not bear any responsibility for storing information. In addition, the user may simply forget the password or it may be hacked. So there is no guarantee that this information will be stored more reliably here than on regular hard disk.
We use optical disks
This method is the most reliable in terms of durability; some manufacturers quote periods of almost a hundred years. However, many have encountered a situation where the blank may not be readable not only after a couple of years, but even after a few months. There are several reasons for this.
What to look for when choosing a disk
In discs, the materials from which the reflective and recording layers are made, as well as the remaining parts of the disc, are very important. 
The recording layer should ideally consist of phthalocyanine, and the reflective layer is made of gold or silver. Although manufacturers can choose a different combination of substances. In addition, users do not need such subtleties. All you need to know is that disks for long-term data storage have a reference to archives in their name or are directly called archived, for example, DVD-R Mitsui MAM-A Gold Archival or Verbatim UltraLife Gold Archival. They cost much more and it is unlikely that you will be able to find them in stores; you will have to order them from other countries. In addition, they cost much more than regular disks, but they store information longer, up to 100 years.
From the available options you can purchase Verbatim or Sony, made in Taiwan.
The following is a diagram that displays the number of errors in reading information from the disk depending on the time it spent in an aggressive environment. 
Millenniata M-Disk
As can be seen from the graph, this company produces some of the most reliable disks. In fact, most of the differences are in the material and recording method. These media use not organic, but glassy carbon layer to record information.
In this case, instead of changing color, as is done when recording conventional optical drives, here the material is literally burned. 
This allows data to be stored much longer and is less dependent on external factors. You can find many videos on the Internet in which these discs are mocked as best they can, but they continue to work. So if the information is actually stored for a long time, you should consider purchasing discs from this manufacturer.
Means of long-term storage and accumulation of data (external storage device) provide recording and reading of large amounts of information, which can be used as: program texts in languages high level, machine code programs, data files, etc. Flexible storage devices are mainly used as external storage devices in PCs. magnetic disks(HMD) and hard magnetic disk drives (HMD) of the Winchester type.
Floppy disk drives are the main external memory devices of PCs. The information carrier in NGMD is a flexible magnetic disk (FMD), made of synthetic film coated with wear-resistant ferrolacquer. Information on the GMD is placed in a sequential code on concentric circles (tracks), each of which is divided into sectors. The sector is a unit of data exchange between the OP and the NGMD. One sector can hold 128,256, 512 or 1024 bytes of data. On a PC, the listed data formats can be installed programmatically.
The GMD has an installation hole (OU) for fixing the disk in the drive and an index hole (IO) for identifying the beginning of the tracks. To protect against adverse effects of the external environment, the GMD is placed in a rectangular envelope that has a slot for supplying magnetic heads (SMG), an index hole slot (FPO) and a hole for fastening the GMD in the disk drive (OCD). The information that is recorded on the GMD is divided into official and operational according to its purpose. Service information used to control and synchronize the operation of the float drive. It, in turn, is divided into information identifying the track and information identifying the sector. Operating information represents user data.
The capacity of the HDD in a PC is 160 KB or more, depending on the number of magnetic heads in the drive and the density of data recording on the HDD. There are the following types of HDMD: with single and double recording density; unilateral - with one and bilateral - with two MGs. In double-sided HDDs, both surfaces of the HDD can be used to write and read data. In accordance with the types of non-volatile disk drives, the corresponding marking of the disk drive has been adopted: SS - single-sided single-density disc; SD - double-density single-sided disc; DD is a double-sided, double-density disc.
Along with float drives, developed PC models are also equipped with hard disk drives of the Winchester type. Their distinctive features are a hermetically sealed single design of the disk, magnetic read-write heads and their drive, a small gap (compared to conventional NDMs) between the magnetic heads and the disk surface (0.5 microns), low clamping pressure of the magnetic head (10 g per compared to 350 g in conventional NMD), small thickness of the magnetic disk.
The hermetically sealed design increases operational reliability by 2 times compared to conventional NMD. Reducing the gap between the disk surface and the magnetic heads significantly increases the longitudinal and transverse recording density. NMDs of the "Winchester" type are considered the third generation of NMDs and have characteristics close to the maximum. Thus, an NMD with a diameter of 356 mm on one surface can include up to 1770 tracks (1300 MB of information).
Development of modems.
The first information processing systems, in which telegraph equipment was used to connect subscribers to a computer, were created in the early 60s. In such systems, transmission was carried out using conventional telegraph equipment at relatively low speeds, not exceeding 110 bits/sec.
The next stage in the development of data transmission systems was the development of modems that provide the ability to transmit binary information over telephone lines.
Modem- electronic device, endowed with the functions of data modulation at the transmitting end of the communication line and demodulation at the receiving end of the communication line. Modulating a signal means converting a signal to a form that allows it to be transmitted over long distances. For example, a typical acoustic modem is equipped with two cup-shaped receptors on which handset. The modem is connected to a computer, from which it receives information in the form of a sequence of binary signals - bits. However, the phone is designed to transmit audio frequency, and binary bits are just electrical impulses, inaudible to the human ear. Therefore, electrical impulses are first converted into audio frequency signals in the modem and then transmitted over telephone lines. At the other end, the reverse process occurs, converting audio frequency signals into a sequence of binary electrical pulses - bits suitable for computer operation. Such transformations are called modulation and demodulation; the described device is just a simple modem.
The first modem samples had relatively low speed data transfer, however, later the transmission speed over switched channels increased to 1200 bps in duplex mode - the mode of simultaneous input and output of information or up to 9600 bps in half-duplex mode - a mode intended for sequential input and output of information.
Intensive development began in the mid-60s specialized systems information processing based on dedicated channels. Such systems are created to meet the needs of individual organizations that own both computing resources and communication channels. However, the operation of such systems has shown that the computing resources and communication channels used in them are not used effectively enough, the systems turn out to be expensive and poorly adapted to changing conditions. The need of many users to turn to powerful computers for relatively short periods of time.
All this led to the development of shared data transmission systems, in which many users can use communication networks public use connect to your choice various means information processing.
Keyboard.
Keyboard important and universal device entering information into a computer.
Based on the location of the keys, desktop keyboards are divided into two main types, which are functionally in no way inferior to each other. In the first version, the function keys are located in two vertical rows, and there are no separate groups of cursor control keys. This keyboard has a total of 84 keys.
The second version of the keyboard, which is usually called improved, has 101 or 102 keys. Almost all desktop personal computers are equipped with this type of keyboard today. Professionals do not like this keyboard due to the fact that the function keys have to be reached far, to the very top row of keys across the entire letter keyboard. However, the quantity function keys The improved keyboard has not 10, but all 12.
In a laptop computer, the keyboard is usually a built-in part of the design.
The location of the letter keys on computer keyboards standard. Today the QWERTY standard is widely used -by first six Latin letter keys of the top row. It corresponds to the domestic standard YTSUKEN for the arrangement of the Cyrillic keys, which is almost similar to the arrangement of the keys on a typewriter.
Standardization in the size and arrangement of keys is needed so that the user can work “blindly” on any keyboard without relearning. The blind ten-finger method of work is the most productive, professional and effective. Unfortunately, the keyboard, due to low user performance, turns out to be the biggest bottleneck of a high-speed computing system today.
Working with the keyboard is very simple and intuitive. In order to assign each keyboard character to a specific byte of information, a special table of ASCII codes (American Standard Code for Information Interchange) is used - an American standard code for information exchange used on most computers.
When a key is pressed, the keyboard sends an interrupt signal to the processor and causes the processor to pause its operation and switch to the keyboard interrupt routine.
In this case, the keyboard is in its own special memory remembers which key was pressed (usually up to 20 codes of pressed keys can be stored in the keyboard memory if the processor does not have time to respond to the interrupt). After the code of the pressed key is transmitted to the processor, this information disappears from the keyboard memory.
In addition to pressing, the keyboard also notes the release of each key, sending the processor its own interrupt signal with the corresponding code.
Characters are entered from the keyboard only at the point on the screen where the cursor is located. The cursor is a rectangle or line of a contrasting color, one character long.
Special keyboard keys: Special (service) keys perform the following main functions: (ENTER) - input of commands for execution by the processor; (ESC) - canceling any action; (TAB) - moves the cursor to the tab position; (INS) - switches the mode of inserting a character at the cursor position to the mode of leaving a character at the cursor position;
(DEL) - deletes a character at the cursor position;
(BACKSPACE) - deletes a character to the left of the cursor;
(HOME) - moves the cursor to the beginning of the text;
(END) - moves the cursor to the end of the text;
(PGUP) - moves the cursor one screen page up in the text;
(PGDN) - moves the cursor one screen page down the text;
(ALT) and (CTRL) - when these keys are pressed simultaneously with any other, the action of the latter changes;
(SHIFT) - holding this key pressed ensures a change of register;
(CAPS LOCK) - locking/unlocking the case of capital letters;
And information. It’s clear that you want to keep things like wedding photos or videos for a long time. However, how to do this?
Concept
Computer science determines that for long-term storage of information, that is, everything possible drives and media you can imagine. As you understand, there are different ways to ensure the safety and security of data. Let's determine what forms of information storage exist.
- Graphic/pictorial. The most ancient method, adapted for It appeared in prehistoric times in the form of cave paintings, went through the stage of painting and developed into the art of photography. In addition, the information in graphical form appears in the form of drawings and diagrams.
- Text. The most common method of storing data today. A wide variety of books and records, libraries. If we talk about reliability, then this storage method is not only not protected from theft, but is also short-lived. The best preserved cookbooks are those that were originally printed on materials adapted to an aggressive environment.
- The next step after the invention of writing is mathematics , a numerical form of storing information. A fairly highly specialized area, it is used to determine the quantitative characteristics of any object in the surrounding space.
- Sound recording. The ability to store sounds only appeared in 1877 with the invention of sound recording devices.
- Video information. The next step in storage graphic information, which appeared with the creation of cinema.
Information processes
Under information processes imply search, storage, transmission, use and The main and primary matter is the preservation of data. What difference does it make whether we can receive or transmit information if we cannot store it?
The main one is the process of storing information. It is a way of transmitting data in space and time. For long-term storage of information, a device or device is used, depending on the type of data stored. To ensure orderliness of this process, use information systems. Any such system is equipped with procedures for searching, placing and input/output of data. Home distinctive feature information system is the presence of all these key procedures. For example, let's compare two libraries. The private library in your closet at home is not an information system, since only you can navigate it. On the other hand, a public city library, in which everything is organized according to card index and there are standardized procedures for issuing and receiving books, is undoubtedly a system.
Computer age
With the development of not even the computer, but the Internet, information systems are being modernized. The storage process has been simplified due to the possibility of converting it into digital form. And despite some people's beliefs that e-books or paintings do not carry a soul, this method of storing data is much more effective than others for long-term storage of information, and it includes all possible information, if only you can convert it into digital form.
Modernity
For long-term storage of information it is used personal computer and its external devices. They are divided into several types depending on the recording method.
- optical disks;
- hard drives;
- flash memory.
They have a wide variety of volumes and are best suited for transmitting and storing information. Hard drives designed for storing large amounts of data, but their reliability leaves much to be desired. And, of course, flash drives. They are a middle link between hard and optical drives; they provide storage of information in sufficient volumes and for a sufficiently long period of time, just do not get them wet. In any case, the storage method is up to you.
Topic No. 2. Technical means of information storage
Target: Give basic concepts of the physical and logical organization of data storage on a personal computer.
Learning Objectives: Familiarization with internal and external devices computers, the main means of storing documents.
Main questions of the topic:
1. The main devices used for long-term data storage on a PC.
2. Logical organization of data storage on magnetic disks.
3. Physical organization of data storage on magnetic disks.
Teaching and learning methods: seminar
Theoretical block
The main devices used for long-term data storage on a PC
Devices used to store information on a PC are external and are very diverse in design. If we use the type of medium (a medium is a material object capable of storing information) used to store information as a classification feature, then they can be divided into the following conditional categories.
Tape-type devices are called streamers.
Disk devices include – magnetic: hard magnetic disks (hard drives), floppy magnetic disks; optical: CD players CD-ROM, etc.
Let's take a closer look at disk devices.
Magnetic disks refer to magnetic computer storage media. As a storage medium, they use magnetic materials with special properties that make it possible to record two magnetic states - two directions of magnetization. Each of these states is assigned binary digits: 0 and 1. Magnetic states are read from the disk by a special head. Magnetic disks are the most widely used storage devices on PCs. A device for reading and writing information on a magnetic disk is called a disk drive.
Let's look at floppy disk drives.
In a flexible magnetic disk, a magnetic layer is applied to a flexible substrate. In terms of size, flexible magnetic disks (floppy disks) come in two types: 3.5" and 5.25". Depending on the number of floppy sides used for recording and the recording density per side, they have the following markings and capacity:
DS/DD - Double Sides, Single Density, 360 KB.
DS/DD-Double Sides, Double Density, 720 KB.
DS/HD-Double Sides, High Density, 1440 KB.
In order for a floppy disk to be used for storing information, it must be formatted. Formatting a floppy disk is the process of writing special marks onto its surface that determine the location information records on the disk and areas not suitable for recording, as well as other control information.
Hard disk drives or hard drives.
They are the main devices in a PC for long-term storage of information.
The name “Winchester” arose by chance because the markings of the first drives coincided with the markings of the 30/30 caliber Winchester system carbine, which was very popular in America. Structurally, the “hard drive” is a sealed metal case in which there is a block that controls the electronics drive and a set of several disks made of aluminum or ceramics and coated with a layer of magnetic material, located on one rotating axis, which is driven by an electric motor, as well as Reading head block.
SCSI interface(Small Computer Systems Interface). Basic interface small computer systems. Allows you to connect up to 7 devices of various types: “hard drives”; scanners, etc. The data transfer speed ranges from 1.5-5 Mb/s. It is implemented in hardware for use in a PC in the form of an additional adapter inserted into the expansion slot of the motherboard. There is an upgraded version of SCSI - SCSI-2, depending on the modification, the data transfer rate is increased to 20-40 Mb/s.
IDE-ATA (Integrated Drive Electronics – AT Attachment) interface
Created in 1984 on the basis of SCSI in order to simplify and reduce the cost of the latter. It differs in that the electronics that control the interface are not located on a separate adapter, but are located in hard case disk and on motherboard PC. Maximum quantity up to 4 connected devices. It has several upgraded options that differ from each other in the maximum capacity of the drives used and the data transfer speed:
EIDE or ATA-2 drives with a capacity greater than 540 MB are supported. The maximum theoretical transfer speed is 11.1-16.6 Mb/s.
ATA-3 or UDMA-33 increased reliability of drives ( SMART technology– Self Monitoring Analyzes And Report Technology – self-monitoring, analysis and reporting technology that allows drives to report their faults to the system and fix them). The theoretical data transfer speed has been increased to 33 Mb/s. The EIDE interface has become standard for PCs.
Storage media
Flash - memory– small-sized external memory, with a capacity of 128 MB to 4 GB, connected to a computer via a USB port.
Reliable storage of information is a problem familiar to most modern enterprises, the solution of which always raises the question: how to obtain high-quality results at relatively low costs? Storing documentation in electronic form ensures not only its safety, but also unhindered accessibility in real mode time.
For long-term and reliable storage of archival information in electronic form, they are used various types information carriers. The main requirement for such media is the exclusion of the possibility of physically making changes to archived data or deleting them. The information carrier must provide one-time recording and at the same time be able to read information multiple times. These requirements are met by information media of the WORM type - Write Once, Read Many (write once, read many times). Other basic requirements for information media include durability and maximum capacity storage of archival data.
Hard drives.
Application hard drives allows you to organize the so-called “operational” storage of archival data, which provides constant on-line access to archival documents. The core of such a storage is a multi-level archival data storage architecture, in which frequently requested archival data is stored on “fast” hard drives with an external Fiber Channel (FC) or Serial Attached SCSI (SAS) interface, and rarely requested archive data is stored on “slow” hard drives with an external Serial ATA (SATA) and NL-SAS interface.
There is an opinion that systems backup- this is a burden for the IT budget, and for the IT department, so to speak, an extra headache. But... Manufacturers of data storage systems (DSS) on hard drives of all levels still recommend using backup systems on tape media as part of such solutions, with the help of which a copy of the data is created, from which, in the event of a failure of the storage system, it can be restored data.
Tape media.
The main purpose of tape media is to create backup copies of operational data (backup). Using tape media, you can also organize archival storage of information. Tape solutions provide near-line access to archived information. The basis of this solution is a robotic tape drive. Today, the volume of data storage on one tape media in the LTO-5 format is 1.5 TB (3 TB with the possibility of data compression). Therefore, tape storage systems are used for reliable information storage of large volumes of archival data. These solutions also have a number of serious disadvantages. Tapes become demagnetized and tear; it is necessary to constantly rewind the tape in cartridges to search for specific file it takes a lot of time for the tape in the cartridge to be rewound to the right place; the fragility of the media forces you to periodically transfer data from the old tape to a new tape. When organizing off-line storage, cartridges with archival data must be stored in rooms with certain environmental requirements or in specialized cabinets.
Optical media.
To organize long-term storage of archival data, it is necessary to use storage devices on optical disks. Such drives ensure the fulfillment of all requirements for archival storage and archival data storage. High reliability, long terms storage of archival data, contactless work with media, authenticity and immutability of archival data, fast random access to archival data, high capacity of optical media, organization of off-line storage of archival data are important parameters when choosing optical media.
Today, the most popular recording format on optical media is the Blu-ray format, which provides high archiving density of up to 100 GB per optical media. WORM support at the hardware level allows you to store data recorded on optical media, archived data that cannot subsequently be deleted or changed. And the “open” recording format of the UDF type allows you to read archived information in any device that supports working with such optical media. The main task is to store rarely requested and unchangeable archive data. Practice shows that the volume of such data is about 80% of the total volume of data stored in online storage. At the same time, 20% of this archival data will never be in demand. By sending such data to archival storage based on optical media, the Customer can free up up to 80% of the storage volume on online storage, which will entail a reduction in the volume and size of the backup “window”.
Solutions on optical media provide near-line access to archived information. The storage volume of archival data in the optical drive and the number of reading devices are determined according to technical specifications. Various types of archival solutions are supported, up to “mirroring” archival data between geographically distributed drives on optical media. Contactless work with optical media eliminates the possibility of damage to the working surfaces of optical media. Provides backward compatibility with previous types of optical media such as CD\DVD. When organizing archival data storage based on an optical drive, there is no need to create backups this data.
Advantages and Disadvantages
Hard drives
- Quick access to archived information
- Random access to archived information
- Popularity of the solution
- High power consumption
- High cost of the solution
- It is required to create backup copies of archived data
- Minimum lifespan (maximum 3 years)
- If a mechanical part fails hard drive, data is almost impossible to recover
- Not intended for off-line storage
Tape media
- Large volumes of archival data storage
- High speed recording information onto tape media
- Low power consumption
- High total cost of ownership
- Minimum life expectancy (on average up to 5 years)
- “Closed” format for recording information on tape media
- Low read access time (minimum 5 min)
- Loss of information upon impact electromagnetic radiation
- Possibility of mechanical damage (tape rupture)
Optical media
- Non-volatility of optical media
- Archival information storage period is from 50 years
- Support for WORM function at the hardware level (immutability of archived data)
- Possibility of organizing off-line storage of archival data
- "Open" recording format (UDF) on optical media
- Low total cost of ownership
- Low power consumption
Conclusion
Most experts in the field of building archival solutions agree that for archival storage of information with the ability to quickly access it, it is best to use a multi-level archival data storage structure. The main criterion in choosing a solution should not be cheapness, but the mechanism for storing and protecting archival data, which is implemented in this solution. Before making a final choice, it is necessary to check all equipment and software for compatibility.
