Where to store data? On what drives to store files for a long time? Information storage devices What is better for storing information.

Reliable storage of information is a problem familiar to most modern enterprises, the solution of which always raises the question: how to get a high-quality result at a relatively low cost? The storage of documentation in electronic form ensures not only its safety, but also its unhindered accessibility in real mode time.

For long-term and reliable storage of archival information in electronic form, different 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 a single record and at the same time be able to read information multiple times. These requirements are met by an information carrier of the WORM type - Write Once, Read Many (write once, read many times). Other basic requirements for information media include durability and maximum archival storage capacity.

Hard drives.

Application hard drives allows you to organize the so-called "operational" storage of archival data, which provides permanent on-line access to archival documents. The core of such storage is a multi-level architecture archival storage data, in which frequently requested archival data is stored on "fast" hard drives with external interface Fiber Channel (FC) or Serial Attached SCSI (SAS), and rarely requested archival data is stored on "slow" hard drives with an external Serial ATA (SATA) and NL-SAS interface.

There is an opinion that systems Reserve copy- 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 (SHD) on hard drives of all levels still recommend using backup systems to tape media as part of such solutions, with the help of which a copy of data is created, from which, in case of failure of the storage system, it will be possible to recover data.

Tape media.

The main purpose of tape media is to create backups operational data (backup). On the basis of tape media, you can also organize archival storage of information. Tape solutions provide non-real-time (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 medium in the LTO-5 format is 1.5 TB (3 TB with the possibility of data compression). Therefore, tape storage systems are used to securely store information of large amounts of archived data. These solutions also have a number of serious drawbacks. Tapes are demagnetized, torn, it is necessary to constantly rewind the tape in cartridges, it takes a lot of time to search for a specific file, while the tape in the cartridge is 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.

For organization long-term storage archived data, you must use optical disc drives. Such drives ensure the fulfillment of all requirements for archival storage and archival data storage. High reliability, long periods of storage of archival data, contactless work with media, authenticity and immutability of archived data, fast random access to archived data, high capacity of optical media, organization of off-line storage of archived data are important parameters when choosing optical media.

Today, the most popular optical media recording format is the Blu-ray format, which provides a high archiving density of up to 100 GB per optical media. Support for WORM at the hardware level allows you to store archived data recorded on optical media, which cannot be deleted or changed later. And the "open" recording format of the UDF type allows you to read archival information in any device that supports working with such optical media. The main task is to store rarely requested and unchangeable archived data. Practice shows that the amount of such data is about 80% of the total amount of data stored on the operational (on-line) storage. At the same time, 20% of these archived data will never be in demand. By sending such data to archival storage based on optical media, the Customer can free up to 80% of the storage volume on the operational (on-line) storage, which will entail a reduction in the volume and size of the backup window.

Solutions on optical media provide non-real-time (near-line) access to archival information. The volume of storage of archived data in the drive on optical media and the number of readers is determined according to terms of reference. Various types of building archival solutions are supported, up to the "mirroring" of archival data between geographically distributed drives on optical media. Non-contact 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 storage of data based on a drive on optical media, it is not necessary to create backup copies of this data.

Advantages and disadvantages

Hard drives

• Online access to archival information
• Random access to archived information
• Solution Popularity
• High power consumption
• Expensive solution
• Required to back up archived data
• Minimum "terms" of life (maximum 3 years)
• If the mechanical part of the hard drive fails, data recovery is almost impossible.
• Not intended for organizing off-line storage

Tape media

• Large volumes of archival data storage
• High-speed recording of information on tape media
• Low power consumption
• High total cost of ownership
• Minimum "terms" of life (on average up to 5 years)
• "Closed" format for recording information on tape media
• Low read access time (minimum 5 min)
• Loss of information when exposed electromagnetic radiation
• Possibility of mechanical damage (tape rupture)

Optical media

• Non-volatility of optical media
• Storage period of archival information from 50 years
• Support for the 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 specialists in the field of building archival solutions agree that for archival storage of information with the possibility of online access to it, it is best to use a multi-level structure of archival data storage. The main criterion in choosing a solution should not be cheapness, but the mechanism for saving and protecting archived data, which is implemented in this solution. Before making a final choice, it is necessary to check all the equipment and software for compatibility.

In recent years, the concept of information life cycle management has become widespread, which is based on the principle of dividing the total data array into classes depending on the content, frequency of accesses and storage period. In accordance with this approach, three key tasks of electronic data storage are distinguished: online access to information, backup and archive storage. To solve each of them, different equipment is used - according to specific requirements to storage and access.

Operational access. A typical example is a file server whose main task is to immediately provide the necessary data. a large number corporate network users. Basic requirements for similar systems- continuity of access and high speed of work. The ideal solution is a RAID array.

Backup. This storage stage implies high write and read streaming speeds and a large storage capacity. The longevity of the storage does not really matter, since backups are made regularly. The best choice would be systems based on tape drives.

Archival storage. In this case, important information is supposed to be stored for a long time while providing quick access to it, which dictates quite specific requirements for storage technologies and equipment, in particular, long-term storage of large amounts of information unchanged. All these conditions are met by robotic optical disc libraries.

It should be noted that in most European countries and the United States, the need for archival storage of business-key information is enshrined at the legislative level. About 25,000 directives have been adopted around the world, including decrees of governments and individual ministries in Germany, Italy, the United States, Great Britain and other countries requiring the preservation of data on financial transactions, exchange transactions, medical research and insurance payments for five to ten years .

Legislative standards for data storage are being actively developed in our country. The planned accession of Russia to the WTO is a powerful catalyst for this process. In the near future, many companies will be required by law to store data for an extended period, so they will have to upgrade their storage systems. Therefore, the global growth rate of the archival storage market in Russia will most likely be significantly exceeded.

FEATURES OF ARCHIVE STORAGE

The first and most important requirement for an electronic archive is the exclusion of the physical possibility of deleting or changing data both through negligence and malicious intent. In other words, the information carrier must provide a one-time write with multiple reading (True Write Once Read Many, True WORM). As a result, the protection of data from deletion should not be software, but hardware. In addition, storage durability and high media capacity are key requirements. This can significantly reduce the total cost of ownership (TCO) of the system and meet the storage requirements of the largest companies, including government and industrial enterprises.

It follows from these conditions that neither RAID arrays nor tape drives can cope with the task of archival data storage. Despite this, in Russia the main part information resources stored on hard drives or RAID arrays. Hard drives are trusted even with information that requires long-term and reliable storage. Meanwhile, the principle of operation hard drive implies constant mechanical movement, which implies device failures and periodic loss of information. Manufacturers do not give guarantees for the performance of a hard drive for decades. Trusting the most valuable data RAID arrays, users sometimes do not attach importance to the fact that RAID technology was created to make up for the unreliability and fragility of the hard drive.

Similar questions arise when trying to build an archive data warehouse based on tape drives: the fragility of the media forces you to periodically transfer data from the old tape to the new one. In addition, the tape needs maintenance - if it is not in use, it must be rewound regularly to prevent degaussing. This technology has other disadvantages, in particular, direct access to an arbitrary file on the tape is impossible.

To solve the problem of archival data storage, a new class of specialized devices was developed - archive drives. These robotic optical disc libraries, controlled by specific software, build a robust storage system to support automatic information lifecycle management.

HARD DRIVE FAILURE STATISTICS

Google Inc. conducted an independent analysis of hard drive failure statistics. The accumulated database (more than 100,000 HDD copies) is many times larger than any other similar study that has been published.

The results clearly demonstrate the inefficiency of using hard drives in long-term archive storage systems: the cumulative percentage of hard drive failures reaches 25% by the end of the fourth year of operation (see Figure 1). As a result, hard disk-based systems must be redundant, support a migration and backup infrastructure, and be subject to frequent after-sales service. This explains the high total cost of ownership for hard drive-based archives.

For building large information storage systems, it is essential that in a multi-disk array (more than 10 hard drives) continued operation without maintenance becomes unlikely even after a few years after the start of operation (see Tables 1 and 2), and more than half of the failures cannot be predicted from using state-of-the-art embedded failure prediction technologies (SMART).

Even with constant maintenance, backup and replacement of disks in the system, users should be aware that, according to statistics, more than a third of all HDDs fail in the fifth year of operation. Given obsolescence, this leads to significant difficulties in ensuring timely replacement. Thus, in order to reduce the risk of data loss, it becomes most expedient to completely replace drives after three to four years of operation, which entails additional costs.

RELIABILITY OF INFORMATION STORAGE ON OPTICAL DRIVES

According to the Enterprise Strategy Group (ESG), of all existing technologies, robotic optical disc drives (DVD / BD libraries) are the best for long-term data storage, using which the total cost of information storage is much lower than in the case of alternative technologies.

The immutability of data stored on optical media is guaranteed at the physical level, since the writing process is an irreversible change in the structure of the disk as a result of crystallization of the amorphous layer, which corresponds to the True WORM write-once standard. The stored data cannot be erased or modified - it is read-only.

The most common type of optical media used for today's archive drives are DVD discs. DVD manufacturers produce discs with a special hard coating, which guarantees the safety of information and fully complies with the international ECMA standard, while the service life of the media exceeds 30 years.

Thus, optical technologies provide the following advantages:

They guarantee exceptionally reliable data storage for decades;

The True WORM specification is supported at the physical level, since during the recording process an irreversible change in the state of matter occurs;

The capacity of one carrier is already 50 GB. This allows you to create data warehouses of significant volume and increase them if necessary;

Blu-ray Disk technology provides random access to data, and the positioning speed laser head on the disk is the same as for hard disks.

RESEARCH METHODOLOGY

To confirm the service life of discs, their samples are tested using the artificial aging method. The discs will meet the standard if 95% of the samples have a predicted shelf life of more than 30 years.

During the tests, indicators of errors in reading disks are determined. If the corresponding critical levels are exceeded, then read errors become unrecoverable and the sample becomes unusable, after which the time to failure is calculated. Based on the results obtained, the expiration time under normal conditions is determined.

During testing, the disks are placed in a special chamber with an elevated temperature, while diffusion processes in the carrier are activated, which imitates the natural aging of the material. In addition, the discs are tested in conditions of high humidity, aggressive environments, the influence of microorganisms and dust, and mechanical stress.

First, the health of the disk is measured at high temperature. In each subsequent experiment, the temperature is lowered by 50C and brought up to 600C. With each step, the life of the disk increases. Data for room temperature are approximated based on the shape of the resulting performance curve. So, for a polycarbonate substrate, the shelf life of discs at room temperature reaches 133 years.

Special hard coating ensures long-term preservation of information recorded on DVD thanks to better defense from scratches. This is confirmed by tests on the HEIDON-14 tester: scratches are applied with a steel ball with a diameter of 7 mm with a non-woven backing at a speed of 1000 mm/min (see Figure 2). In addition, the anti-static component of the coating quickly removes static electricity from the surface of the disc and prevents dust from adhering during use and storage (relevant tests were carried out in a dusty chamber for 24 hours). The oil-repellent surface reduces the risk of data loss if someone accidentally touches the surface of the drive and makes it easier to erase fingerprints (see Figure 3). Hard Coated DVD fully complies with all performance standards and remains highly stable when tested at elevated temperature and humidity (temperature 80°C, relative humidity 90%).

Tests conducted by ECMA International confirm that robotic libraries based on certified DVD discs with a hard coating provide reliable storage of archival data for 30 years and fully meet the standards of archival storage of information.

IMPROVING STORAGE TECHNOLOGIES

The problem of archival storage becomes more and more urgent as the volume of stored data grows exponentially. On a global scale, the amount of archival information is growing much faster than all other information. Wherein fast access only 20-30% of the information is required. By 2010, its total volume will reach one zettabyte, i.e. 1021 bytes.

Currently, DVDs can store 9.4 GB on a single medium, while Blu-ray-based drives can store up to 50 GB on a single BD. In the coming years, it is planned to increase the capacity of mass-produced optical discs to 100 GB, and in the future to 200 GB (see Figure 4). This will make optical technology even more accessible.

Continuity of technology is important: modern optical drives support CDs released by
25 years ago. In the future, the form factor of optical discs will not change, which allows us to count on the compatibility of optical discs with drives of the future.

BLU-RAY TECHNOLOGY

Modern Blu-ray optical technology provides high-density archiving on media with a capacity of 25 or 50 GB each, with a capacity of 100 or even 200 GB achievable in the future. Single-sided media can have one or more recording layers of 25 GB each, support write-once (BD-R) and re-write (BD-RE), and provide highly efficient sector-by-sector error correction. The Blu-ray Disc is 120mm in diameter and has a hard surface.

Blu-ray drives are read/write compatible with CD/DVD media. The technology is supported by all major manufacturers of drives and media, as well as file system UDF. Modern Blu-ray drives provide 2x write speed (72 Mbps) and 5x read speed (for single layer media).

USE OF BACKUP DRIVES

Archive drives are used in the infrastructure of an enterprise information system when long-term, reliable data storage is needed (see Figure 5). The control software automatically migrates data from the network or from the server according to predefined rules. It is estimated that approximately 80% of the data stored on Tier 1 media does not require frequent access, and 20% of it will never be needed. It makes sense to store such data on optical archive drives, thereby freeing up expensive disk space in a RAID array.

When choosing an archival storage system, DVD and BD optical technologies should be preferred. Only they provide fulfillment of all storage requirements, including such parameters as high reliability and long-term storage, authenticity and immutability of data, fast random access to data, high storage capacity, expandability. Optical technologies have been proven over decades and thousands of installations around the world.

Igor Korepanov - Marketing Director of the company "Electronic Archive". He can be contacted at:

Preservation archival documents- it is one of the main areas of work of archivists. From how correctly the strategy for storing documents was chosen, their physical condition and the possibility of using them for a wide variety of purposes depend.

Procedures for ensuring the safety of electronic documents can be conditionally divided into three types:

• -- Ensuring the physical safety of files with electronic documents;
• -- providing conditions for reading information in the long term;
• -- providing conditions for the reproduction of electronic documents in the so-called human-readable form.

The first aspect of ensuring the safety of electronic documents is a practically solved problem, and for all types of storage. This decision is connected not so much with the creation of optimal storage conditions for media with electronic information, but with the physical placement of electronic documents. In order for computer files not to be lost, it is necessary to store them in two or more copies placed on separate electronic media (working and backup or archival media). Then, if one of the media is lost, you can quickly make a duplicate of the files from the rest.

The widespread practice of storing electronic documents shows that their working copies, as a rule, are located on a hard drive or an organization's server, and backup copies (copies) can be created on a backup server or RAID array, streamer (magnetic) tapes, magneto-optical and optical disks (CDs). -RW, DVD-RW). Very few owners of electronic information resources separate the archival part from them and store it exclusively on external media. This is natural: the rate of growth in the volume of stored resources lags behind the rate of decline in prices for hard drives, which allows organizations to increase their server potential with a large margin.

It is also important to choose the type of media, its durability. This choice depends on the type of stored electronic documents and their total volume, on the expected period of storage of documents and providing access to them, on the nature of the production of the media themselves and on the expected modes of their storage, on the requirements for ensuring the authenticity of documents. For example, storage of voluminous and complexly structured information resources (integrated databases, geo- and multimedia systems, project and design documentation, original layouts of printed publications) is best done on high-capacity electronic media in order not to violate the integrity of documents.

For storing electronic documents within 5 years, any modern storage media (including magnetic diskettes) are quite reliable. The main thing is to pay attention to the reputation of the manufacturer and the country of origin, which ultimately focuses on the cost of the media, as well as comply with the minimum requirements for their storage modes. As with any product, the rule applies here: cheap is not good. For the same reason, when organizing long-term storage of electronic documents, one should, for example, choose optical discs (“blanks”), the retail price of which will not be lower than 22-25 rubles.

Particular attention should be paid to the choice of media type in case of possible use of electronic documents as written evidence or forensic evidence. If it is unrealistic to give legal force to documents using electronic digital signature(EDS), then they should be copied in a timely manner to CD-R - optical discs with a single record of information.

For long-term storage of electronic documents on external media, the best solution would be to use optical CDs. They are unpretentious in storage and quite reliable for 10-15 years. More is not required. After this period, you will inevitably have to either rewrite the files to another type of media (because it will be impossible to read information from the CD), or convert electronic documents to other formats and also rewrite to modern and capacious media.

Optical discs are considered the most durable media. Some manufacturers determine the shelf life of their products at almost 200 years. How justified this can only be shown by practice, and it is extremely contradictory. On the one hand, there is evidence of the successful use of records on CD for 10-15 years, on the other hand, there are regular reports of failures to read information from these discs. On the other hand, in recent years there have been especially many complaints about access to files recorded on CD-R. Analysts still find it difficult to give an exhaustive explanation possible causes: are the failures in reading files due to the inferiority of the CD-R technology, or some other factors (violations of the technology in the manufacture of "blanks", violations of the conditions and storage mode, technological incompatibility of recording and reading devices).

Creating multiple instances of files does not exhaust the scope of work to ensure their safety. To minimize the cost of maintaining these instances, it is necessary to create optimal conditions for storing storage media. The specifics of conditions and storage mode is largely determined by the type electronic media. For example, for long-term storage magnetic media you need special equipment that would protect them from magnetic and electromagnetic effects of the environment, or place them away from powerful sources of electromagnetic fields - electric motors, heaters, elevator equipment, etc. Cassettes (reels) with magnetic tapes must be rotated every 1 ,5 years to remove static voltage and prevent the so-called copy effect. Common points in the storage of any electronic media are placing them in a vertical position, protection from mechanical damage and deformations, pollution and dust, exposure to extreme temperatures and direct sunlight.

Memory device - a storage medium intended for recording and storing data. The operation of a storage device can be based on any physical effect that brings the system to two or more stable states.

Storage devices are divided into 2 types:

external (peripheral) devices

internal devices

TO external devices include magnetic disks, CDs, DVDs, BDs, streamers, hard disks (hard drives), and flash cards. External memory is cheaper than internal memory, which is usually created on the basis of semiconductors. In addition, most external storage devices can be transferred from one computer to another. Their main drawback is that they are slower than internal memory devices.

TO internal devices include RAM, cache, CMOS, BIOS. The main advantage is the speed of information processing. But at the same time, internal memory devices are quite expensive.

floppy disk drive (floppy disk drive)

The use of floppy disks is a thing of the past. There are two types and provide storage of information on diskettes of one of two formats: 5.25 "or 3.5". 5.25" floppy disks are practically non-existent nowadays (maximum capacity is 1.2 Mb). For 3.5" floppy disks, the maximum capacity is 2.88 Mb, the most common capacity format for them is 1.44 Mb. Flexible magnetic disks are placed in a plastic case. In the center of the floppy disk there is a device for gripping and rotating the disk inside the plastic case. A floppy disk is inserted into a disk drive that rotates at a constant angular speed. All diskettes are formatted before use - service information is applied to them, both surfaces of the diskette are divided into concentric circles - tracks, which in turn are divided into sectors. Sectors of the same name on both surfaces form clusters. The magnetic heads are adjacent to both surfaces and, as the disk rotates, they pass by all track clusters. Moving heads along the radius using a stepper motor provides access to each track. Writing/reading is performed by an integer number of clusters, usually under the control of the operating system. However, in special cases, it is possible to organize writing / reading bypassing the operating system, using the BIOS functions directly. In order to preserve information, floppy magnetic disks must be protected from exposure to strong magnetic fields and heating, since such exposure can lead to demagnetization of the media and loss of information.

HDD (hard disk drive)

The hard disk drive is one of the most advanced and complex devices in a modern PC. Its disks are capable of holding many megabytes of information transferred at an enormous speed. The basic principles of a hard disk have changed little since its inception. Looking at a hard disk drive, you will see only a solid metal case. It is completely sealed and protects the drive from dust particles. In addition, the case shields the drive from electromagnetic interference.

The disk is a round plate with a very flat surface, often made of aluminum, less often made of

ceramics or glass coated with a thin ferromagnetic layer. Magnetic heads read and write information to discs. Digital information is converted into an alternating electric current supplied to the magnetic head, and then transmitted to magnetic disk, but already in the form of a magnetic field, which the disk can perceive and "remember". Under the influence of an external magnetic field, the own magnetic fields of the domains are oriented in accordance with its direction. After the termination of the action of the external field, zones of residual magnetization are formed on the surface of the disk. In this way, the information written to the disc is preserved. Areas of residual magnetization, when the disc rotates opposite the gap of the magnetic head, induce an electromotive force in it, which varies depending on the magnitude of the magnetization. The disc pack, mounted on a spindle axle, is driven by a special motor compactly located underneath. The rotation speed of the discs is typically 7200 rpm. In order to reduce the time it takes for the drive to enter the operating state, the engine operates in the forced mode for some time when it is turned on. Therefore, the computer power supply must have a margin for peak power. The advent of Giant Magnetic Resistance (GMR) heads invented by IBM in 1999 led to an increase in recording density to 6.4 GB per platter in products already on the market.

The main parameters of the hard disk:

Capacity - the hard drive has a capacity of 40 GB to 200 GB.

Data reading speed. The average today's figure is about 8 MB / s.

Average access time. It is measured in milliseconds and indicates the time it takes the disk to access any area you select. The average is 9 ms.

Disk rotation speed. An indicator that is directly related to the speed of access and the speed of reading data. The speed of rotation of the hard disk mainly affects the reduction of the average access (search) time. The improvement in overall performance is especially noticeable when fetching a large number of files.

The size of the cache memory is a small, fast buffer memory in which the computer stores the most frequently accessed data. The hard drive has its own cache memory up to 8 MB.

Company manufacturer. Only the largest manufacturers can master modern technologies, because the organization of the manufacture of the most complex heads, plates, controllers requires large financial and intellectual costs. Hard drives are currently manufactured by seven companies: Fujitsu, IBM-Hitachi, Maxtor, Samsung, Seagate, Toshiba, and Western Digital. Moreover, each model of one manufacturer has its own, only inherent features.

streamers

The classic way to back up is to use streamers - devices

tape recordings. However, the capabilities of this technology, both in terms of capacity and speed, are severely limited by the physical properties of the media. A streamer is very similar to a cassette recorder. Data is written to a magnetic tape that is pulled past the heads. The disadvantage of a tape drive is that it takes a long time to sequentially access data when reading. The capacity of the streamer reaches several GB, which is less than the capacity of modern hard drives, and the access time is many times longer.

Flash card

Devices made on a single chip (chip) and having no moving parts are based on electrically reprogrammable flash memory chips. The physical principle of organizing flash memory cells can be considered the same for all manufactured devices, no matter how they are called. Such devices differ in interface and controller used, which causes a difference in capacity, data transfer rate and power consumption.

Multimedia Card (MMC) and Secure Digital (SD)– leaves the scene due to limited capacity (64 MB and 256 MB, respectively) and low speed.

smart media- the main format for cards of wide application (from bank and metro travel cards to identity cards). Thin plates weighing 2 grams have open contacts, but a significant capacity for such dimensions (up to 128 MB) and a data transfer rate (up to 600 Kb / s) led to their penetration into the field of digital photography and wearable MP3 devices.

memory stick- "exclusive" format by Sony, almost never used by other companies. The maximum capacity is 256 MB, the data transfer speed reaches 410 Kb / s, the prices are relatively high.

Compact Flash (CF)- the most common, versatile and promising format. Easily connects to any laptop. The main area of ​​application is digital photography. In terms of capacity (up to 3 GB), today's CF cards are not inferior to IBM Microdrive, but they lag behind in data transfer speed (about 2 MB / s).

USB flash drive - sequential USB interface with a throughput of 12 Mbps or its modern USB 2.0 variant with a throughput of up to 480 Mbps. The carrier itself is enclosed in a streamlined compact body, reminiscent of a car keychain. The main parameters (capacity and operating speed) completely coincide with CompactFlash, since the memory chips themselves remain the same. It can serve not only as a "carrier" of files, but also work like a regular drive - you can run applications from it, play music and compressed video, edit and create files. Low average access time to data on Flash disk - less than 2.5 ms. Probably class drives USB Flash Drive, especially with a USB 2.0 interface, in the future will be able to completely replace conventional floppy disks and partially rewritable CDs, Iomega ZIP media, and the like.

PC Card (PCMCIA ATA)- the main type of flash memory for compact computers. Currently, there are four formats of PC Cards: Type I, Type II, Type III and CardBus, differing in size, connectors and operating voltage. The PC Card can be backwards compatible in slots from top to bottom. The capacity of the PC Card reaches 4 GB, the speed is 20 Mb/s when exchanging data with the hard disk.

How to ensure the safety of information? Do not rush to answer this seemingly simple question. To get started, take a close look at the advantages and disadvantages of available storage media. Manufacturers will help you with the pluses, and we will raise the pitfalls from the abyss of information together in this article.

How to ensure the safety of information? What materials should be used for this? What should be considered when choosing storage media? Do not rush to answer these seemingly simple questions. To begin with, you should carefully consider the advantages and disadvantages of the available storage media. Manufacturers will help you with the pluses, and we will raise the pitfalls from the abyss of information with you in this article.

Sometimes a random napkin or an old business card is enough to save vital information. But for recording a financial report or a video from a recent corporate party, such storage media is hardly suitable. In addition, there are vast amounts of information of legal, commercial, historical or scientific value. It must be stored for years or even centuries, and therefore the choice of storage medium is of paramount importance. What to choose in the dynamic world of technological innovations and old proven media? We bring to your attention an overview of the main means of storing information from their most unsightly side.

Paper

Paper is the oldest medium for storing information. As is known, the spontaneous change in the properties of paper as a result of aging is associated with a change in the chemical structure and, in particular, its main component, cellulose. The development of technology has had a positive impact on the quality of materials used in the production. New technological procedures have significantly improved the physical, chemical and electrostatic properties of paper. Scientific progress has also led to more advanced ways of printing information: carbon black and feather inks, slate pencils, fountain pens, printing ink, typewriter ribbons, and printer inks.

The method of applying information, as well as the quality of the material itself, ultimately determine the long-term storage of data on paper. Our ancestors wrote letters with lead or carbon-based ink, which does not change its properties for centuries and is a chemically resistant substance. The text was usually applied by physically damaging the surface - by punching. Typewriters and dot-matrix printers used the same technology, in which inorganic dyes were sprayed by contact: first, the paper was pressed through, and then the dye penetrated into the material to a given depth.

This old way of applying information by mechanical punching is not comparable to what is used today in conventional inkjet and laser printers. Jet printer sprays liquid ink from a certain distance without physically changing the surface. Manufacturers do not report the depth of penetration of ink, however, as well as what they are made of. With laser printers, the situation is even worse. According to the technology, toner powder is applied to paper, then the sheet passes through rollers heated to a high temperature, and the powder granules are sintered. In this case, the toner is often not absorbed into the paper at all. There are cases when, after a few years, the paint simply fell off the sheet in whole pieces, like fragments of an old mosaic.

camera roll

With photographic film, things are much better than with paper.

Firstly, production technologies, at least for black and white film, are time-tested. They practically do not change, so it is safe to say that the materials will last for a long time, even if you buy the most ordinary film from the nearest photo store. At the same time, the chances of a long life for professional films are certainly higher, since they differ from amateur ones in special additives that slow down the aging process. However, the requirements for storage conditions for professional films are somewhat stricter.

Secondly, unlike paper, film has an expiration date, during which manufacturers guarantee the preservation of its properties. After this time, a chemical process begins, causing the aging of the film, which can be contained if the temperature, humidity and light conditions of storage are observed.

A significant drawback in working with photographic film is that the cost of film and equipment (camera or camera, reagents for developing and fixing the image, projectors for viewing finished materials) is relatively high.

Magnetic tape

Surely you remember your old cassette recorder, which was later replaced by video players and VCRs. The information carrier in them was replaceable cassettes. With the development of information technology, magnetic tape began to be used to store information in digital form.

Special devices (streamers) in digital form write information to tape on a tape, which is stored in much the same way as on a computer: in the form of files. In the past, tape drives were widely used to store backup copies of data. In everyday life, such devices have not taken root. First of all, this is due to the complexity of access to information recorded on the tape. First, you need to rewind it to the place where the necessary information is recorded, and then wait until the data is read into the computer's memory. Not everyone has the patience for such technological troubles. At one time, expansion boards for a computer were produced, with the help of which it was possible to store data on audio cassettes, and later on video cassettes, using an audio or video recorder in conjunction with a board that is inserted into a computer.

The long-term storage of information on a magnetic tape largely depends on the quality of the tape itself. For example, there are low-quality tapes, the magnetic layer from which simply crumbles over time, and if you see noise on the video, it will be problematic to read digital data from such a tape. A special tape for the streamer is designed for longer storage of information and more active use. This is due to the fact that when writing to a tape, a special encoding of information is used, which allows you to reliably restore it when reading it, even if some bits of information are decoded incorrectly (the user will not notice anything). In addition, during recording, several copies of data can be created simultaneously (several tracks can be written in parallel across the width of the tape), which also has a positive effect on the duration of storage.

The problem that potentially awaits every tape lover is the rapid obsolescence of equipment. It is not a fact that in a few years, if the current device breaks down, you will be able to find a replacement for it, even just to read the data and transfer it to a new medium. Another unpleasant moment in working with magnetic film: the cassettes must be rewound regularly. V otherwise the adjoining layers of the film magnetize each other, which means that the magnetic tape will not be able to reliably store information for a long time. Industrial equipment uses robotic complexes that automatically change cassettes as they are full and periodically rewind the tapes.

You need to store tapes with extreme caution, since the magnetic fields that surround us and are completely invisible can damage the information on the tape. So, the use of ferromagnetic metal racks is not allowed. When placing the film on steel racks, it is necessary to demagnetize and close the rack contours: connecting the metal parts of the rack with an electric wire and their effective grounding. It would not be superfluous to recall that a magnetic film, like any media, also requires compliance with a certain temperature and humidity regime.

floppy disks

CD/DVD

Low cost and availability are the main advantages of CDs and DVDs. But, unfortunately, information on them is often completely (or partially) lost after two or three years. This is due to the destruction of the coloring layer caused by exposure to sunlight and ionizing radiation.

Sometimes in the production of large batches, stamping is used, similar to the production of vinyl records. Unlike conventional CDs and DVDs, these discs can last for years.

Manufacturers claim that under proper storage conditions, some types of discs (CD-R, DVD-R) can be used for 100 to 200 years. However, in practice, these optimistic statements are not confirmed.

Hard disk drive (HDD)

Today, perhaps, the most common device for storing information. Hard drives can be internal (installed inside the case) and external (attached to the device using a USB cable). In the latter case, the hard drive is sized to be carried in a jacket pocket and connected to almost any computer via a USB connector.

Every year the cost of a unit of stored information decreases. Information is stored on plates inside a sealed container and covered with magnetic material. The recording technology is similar to a magnetic tape, and the device itself is like a floppy disk. The main difference is in the materials used. In addition, the hard drive contains, firstly, electronics that can fail, for example, from a power surge, and secondly, high-precision mechanics. Due to the fact that the reading heads do not touch the surface of the disc during operation, the surface does not wear out and can serve as a storage area for many years.

In case of careless handling (falling, shaking during operation), hard drives are prone to failure. So, one sharp shake of a fully functional disk may be quite enough to lose all the information recorded on it without the possibility of recovery. If handled with care, discs will last for more than ten years with heavy daily use. However, recently the quality of equipment leaves much to be desired, as in pursuit of low prices, manufacturers save on equipment and materials.

Flash memory (flash memory), flash drives (flash drive)

Flash drives are storage media that use electrically erasable, non-volatile memory for storage. If magnetic tape, floppy disks and hard drives were invented and widely used at the dawn of the development of computer technology, then flash memory has become popular relatively recently. This is due to the breakthrough in the field of chip manufacturing technologies.

There are both expensive large-capacity solid-state drives and budget devices known as flash drives and memory cards. Today they are perhaps the most affordable and convenient means for everyday use. The memory card is a fully electronic device and can be connected to the device via a card reader. Unlike them, flash drives do not require additional mechanisms to connect to a computer.

The reliability of information storage declared by manufacturers is up to ten years. Unlike hard drives, flash drives are not afraid of shaking and falling from a small height. They are light, roomy and have a high capacity to store multiple movies or tens of thousands of documents on a single device.

With everyday use, flash drives often fail, for example, from static electricity, which disables delicate electronics. The reason may also lie in poor-quality manufacturing and mistakes made by engineers when designing cheap devices, especially flash drives. The latter may fail due to a breakdown of the microcontroller. In this case, information can theoretically be recovered directly from the memory chip using special equipment. If the chip itself is damaged, then it is impossible to recover the data.

Technology does not stand still. And even today, scientists are creating such media that seem to ordinary people to be part of sci-fi stories. However, when choosing a storage medium, one should be guided not only by fashionable technological trends, but also by common sense. If a few mobile gigabytes of free space (the size of a standard flash drive) is enough for you to store information, then there is no point in buying expensive gigantic hard drives just to impress your friends.

In addition, it is necessary to take into account the costs of both the purchase of the media itself and the costs associated with recording information and maintaining equipment (for example, as is the case with photographic film). In order to ensure the reliable safety of data, the best solution would be to choose not one, but several storage media that can come to the aid of each other in the event of an unfortunate damage to one of the media.