Clever Geek Handbook
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HDD

Hard magnetic disk drive, or HDD ( English hard (magnetic) disk drive, HDD, HMDD ), hard disk, hard drive - a random access memory device ( storage device ) based on the principle of magnetic recording . It is the main data storage device in most computers .

HDD
Laptop-hard-drive-exposed.jpg
A 2.5-inch SATA hard drive with a 4-pin service connector for accessing the drive’s firmware. Germocorpus opened
File: HardDisk1.ogv Play media file
Unassembled hard disk operation

Unlike a floppy disk ( floppy disk ), the information in the HDD is recorded on hard ( aluminum or glass ) plates coated with a layer of ferromagnetic material, most often chromium dioxide - magnetic disks. A HDD uses one or more plates on the same axis . The read heads in the operating mode do not touch the surface of the plates due to the interlayer of the incoming air flow generated at the surface during rapid rotation. The distance between the head and the disk is several nanometers (in modern disks about 10 nm [1] ), and the absence of mechanical contact ensures a long service life of the device. In the absence of disk rotation, the heads are located at the spindle or outside the disk in a safe ("parking") zone, where their abnormal contact with the surface of the disks is excluded.

Also, unlike a floppy disk, the storage medium is usually combined with a drive, drive, and electronics unit. Such hard drives are often used as a non-removable storage medium.

Since the second half of the 2000s, more efficient solid-state drives have become widespread, displacing disk drives from a number of applications despite the higher cost of a storage unit; At the same time, as of the mid-2010s, hard drives were widely used as inexpensive and high-capacity storage devices both in the consumer segment and corporate.

Content

The name "Winchester"

According to one version of [2] [3] , the drive was named “Winchester” due to IBM Kenneth E. Haughton , project manager, who worked at IBM , and as a result a hard drive was released in 1973 Model 3340 , for the first time combining disk plates and read heads in one all-in-one body. When developing it, the engineers used the short internal name "30-30", which meant two modules (in the maximum layout) of 30 megabytes each, which in tune coincided with the designation of the popular hunting weapon - the Winchester Model 1894 rifle, using a .30-30 rifle cartridge Winchester . There is also a version [4] that the name was solely due to the name of the cartridge, also produced by the Winchester Repeating Arms Company , the first US-made ammunition for civilian “small” caliber smokeless gunpowder that surpassed the cartridges of old generations in all respects and immediately gained the widest popularity.

In Europe and the USA, the name “Winchester” fell out of use in the 1990s, while in the Russian language it was preserved and received semi-official status, and in computer slang it was reduced to the word “screw” (sometimes “Vinc” [5] ).

Data Recording Technologies

The principle of operation of hard drives is similar to that of tape recorders . The working surface of the disk moves relative to the read head (for example, in the form of an inductor with a gap in the magnetic circuit ). When applying an alternating electric current (during recording) to the head coil, the resulting alternating magnetic field from the head gap acts on the ferromagnet of the disk surface and changes the direction of the domain magnetization vector depending on the magnitude of the signal. When reading, the movement of domains at the head gap leads to a change in the magnetic flux in the magnetic core of the head, which leads to the appearance of an alternating electrical signal in the coil due to electromagnetic induction.

Since the late 1990s, heads based on the effect of giant magnetic resistance (HMS) began to be used in the market for information storage devices. [6] [7]
Since the beginning of the 2000s, heads based on the HMS effect began to be replaced by heads based on the tunnel magnetoresistive effect (in them, a change in the magnetic field leads to a change in resistance depending on changes in the magnetic field strength; such heads can increase the probability of reliability of information reading, especially at high densities recording information). In 2007, devices based on the tunnel magnetoresistive effect with magnesium oxide (the effect was discovered in 2005) completely replaced devices based on the HMS effect.

Longitudinal Record Method

Bits of information are recorded using a small head, which, passing above the surface of a rotating disk, magnetizes billions of horizontal discrete regions - domains. In this case, the domain magnetization vector is located longitudinally, that is, parallel to the surface of the disk. Each of these areas is a logical zero or unit, depending on the direction of magnetization.

The maximum achievable recording density using this method is about 23 Gbit / cm². By 2010, this method was almost supplanted by the perpendicular recording method.

Perpendicular Recording Method

The perpendicular recording method is a technology in which bits of information are stored in vertical domains . This allows you to use stronger magnetic fields and reduce the area of ​​the material needed to record 1 bit. The previous recording method, parallel to the surface of the magnetic plate, led to the fact that at a certain moment the engineers ran into a “ceiling” - it was impossible to further increase the density of information on disks. And then they remembered another way of recording, which had been known since the 70s of the last century.

The recording density with this method increased sharply - by more than 30% on the first samples (in 2009 - 400 Gbit / inch², or 62 Gbit / cm² [8] ). The theoretical limit has shifted by orders of magnitude and is more than 1 Tbit / inch².

Perpendicular recording hard drives have been available on the market since 2006 [9] . Winchesters continue the trend of increasing capacity, accommodating up to 10-14 terabytes and using technologies such as helium filling, SMR, HAMR / MAMR in addition to PMR [10] .

Promising Recording Methods

Tiled Magnetic Recording Method

The tiled magnetic recording method ( , SMR) was implemented in the early 2010s. It uses the fact that the width of the reading area is less than the width of the recording head. Tracks are recorded in this method with partial overlap within groups of tracks (packages). Each next track of the package partially covers the previous one (like a tiled roof), leaving a narrow part from it, sufficient for the reading head. Tile recording increases the density of recorded information, but complicates overwriting - with each change, you must completely overwrite the entire package of overlapping tracks [11] [12] .

Thermal Magnetic Recording Method

The method of thermal magnetic recording ( English heat-assisted magnetic recording, HAMR ) remains promising, its refinement and implementation continue. This method uses spot heating of the disc, which allows the head to magnetize very small areas of its surface. After the disk cools, the magnetization “fixes”. For 2009, only experimental samples were available with a recording density of 150 Gbit / cm² [13] . Hitachi experts call the limit for this technology 2.3–3.1 Tbit / cm², and representatives of Seagate Technology - 7.75 Tbit / cm² [14] .

Structured Storage Media

A structured (patterned) storage medium ( English bit-patterned media ) is a promising technology for storing data on a magnetic medium, using an array of identical magnetic cells to record data, each of which corresponds to one bit of information, in contrast to modern magnetic recording technologies, in which a bit of information is recorded on several magnetic domains.

T-ray recording method

In 2019, a group of Russian researchers from the Moscow Institute of Physics and Technology (MIPT) created a new way to write data to hard drives . For this, a prototype carrier was used. [ specify ] , created on the basis of thulium antiferromagnetic orthoferrite (TmFеО 3 ), which was affected by T-radiation (the terahertz range located between the radio wave and infrared ). As a result, the magnetization reversal (spin switching) rate in the carrier was less than 3 picoseconds , which significantly exceeds the performance of carriers used today. This method turned out to be much faster and more efficient than working with a pulsed magnetic field. The developed devices will have a small size and a huge data transfer rate - picoseconds . [15] [16] [17] [18]

Features

 
  • An interface is a technical means of interaction between two heterogeneous devices, which in the case of hard disks is a combination of communication lines, signals sent along these lines, technical means supporting these lines (interface controllers), and exchange rules (protocol). Modern commercially available internal hard drives can use the interfaces ATA (aka IDE and PATA), SATA , eSATA , SCSI , SAS , FireWire , SDIO and Fiber Channel .
  • Capacity ( eng. Capacity ) - the amount of data that can be stored by the drive. Since the creation of the first hard drives as a result of continuous improvement of data recording technology, their maximum possible capacity has been continuously increasing. The capacity of modern hard drives (with a 3.5-inch drive form factor ) for 2016 reaches 6, 8 or 10 terabytes [19] . Unlike the system of prefixes generally accepted in computer science , which designates a multiple of 1024 (see: binary prefixes ), the manufacturers use multiples of 1000 to designate the capacity of hard drives. Thus, the capacity of a hard drive labeled “200 GB” is 186.2 GiB [20] [21] [22] .
  • Physical size ( form factor ; English dimension ) - almost all drives of 2001-2008 for personal computers and servers have a width of either 3.5 or 2.5 inches - the size of standard mounts for them, respectively, on desktop computers and laptops . The formats of 1.8, 1.3, 1 and 0.85 inches are also widespread. Discontinued production of drives in the form factors of 8 and 5.25 inches.
  • Random access time ( English random access time ) - the average time for which the hard drive performs the operation of positioning the read / write head on an arbitrary section of the magnetic disk, depends on the speed of rotation. The range of this parameter is from 2.5 to 16 ms , often in the specifications indicate the average access time of about 8-10 ms [23] . As a rule, disks for servers have the minimum time, disks for portable devices are the largest. For comparison, SSDs have this parameter less than 1 ms, in addition, SSDs are able to process several random requests simultaneously.
  • Spindle speed ( eng. Spindle speed ) - the number of spindle revolutions per minute. Access time and average data transfer rate are largely dependent on this parameter. Currently, hard drives are available with the following standard rotation speeds: 4200, 5400 and 7200 (laptops); 5400, 5700, 5900, 7200 and 10 000 (personal computers); 10,000 and 15,000 rpm. (servers and high-performance workstations). The gyroscopic effect , the influence of which is negligible in stationary computers, prevents the increase in the spindle speed in laptop hard drives.
  • Reliability ( Eng. Reliability ) - is defined as the mean time between failures (MTBF). Also, the vast majority of modern drives support SMART technology
  • The number of input / output operations per second ( IOPS ) - depends on the speed of rotation, the size of the requests and the localization of the requests. For modern 7200 rpm drives, this parameter is estimated at about 75-100 opt./s for random access to the drive, and is determined to a greater extent by random access time [24] [25] . In linear (sequential) operations, “iops” indicators are determined by the total data transfer time and are calculated through the linear read speed and size of operations [26] [27] .
  • Energy consumption is an important factor for mobile devices.
  • G-shock rating - the drive's resistance to sharp pressure surges or shocks, measured in units of permissible overload on and off.
  • The serial data transfer rate ( Transfer Transfer ) for sequential access differs for disk areas (zones, ZBR [28] ) [29] :
    • outer zone of the disk: about 150-200 MB / s;
    • internal disk area: about 70-100 MB / s
  • Buffer volume - a buffer is an intermediate memory designed to smooth out differences in read / write and transfer speeds over the interface. In modern drives, it usually ranges from 8 to 128 MB.

Noise Level

 
Silicone bushings for mounting hard drives. Reduce vibration and noise

Noise level - noise produced by the mechanics of the drive during its operation. Indicated in decibels . Silent drives are considered devices with a noise level of about 26 dB or less. The noise consists of spindle rotation noise (including aerodynamic) and positioning noise.

The following methods are used to reduce noise from hard drives:

  • means of the built-in AAM system. Switching the hard drive to low-noise mode leads to a decrease in performance by an average of 5-25%, but makes the noise during operation almost inaudible;
  • design and technological methods:
  • the use of noise absorbing devices [30] ;
  • by mounting on rubber or silicone washers;
  • full replacement of the mount with a flexible suspension.

Device

 
Hard disk drive device layout

The hard disk consists of a hermetic zone and an electronics unit.

Hermozone

 
Disassembled Samsung HD753LJ hard drive with a capacity of 750 GB
 
Magnet of a solenoidal low-inertia motor that moves the head of a hard disk
 
Disassembled hard drive

Гермозона включает в себя корпус из прочного сплава, собственно диски (пластины) с магнитным покрытием (в некоторых моделях разделённые сепараторами), а также блок головок с устройством позиционирования и электропривод шпинделя .

Вопреки расхожему мнению, в подавляющем большинстве устройств внутри гермозоны нет вакуума . Одни производители делают её герметичной (отсюда и название) и заполняют очищенным и осушенным воздухом или нейтральными газами, в частности азотом , а для выравнивания давления устанавливают тонкую металлическую или пластиковую мембрану (в таком случае внутри корпуса жёсткого диска предусматривается маленький карман для пакетика силикагеля , который абсорбирует водяные пары, оставшиеся внутри корпуса после его герметизации). Другие производители выравнивают давление через небольшое отверстие с фильтром, способным задерживать очень мелкие (несколько микрометров ) частицы. Однако в этом случае выравнивается и влажность, а также могут проникнуть вредные газы. Выравнивание давления необходимо, чтобы предотвратить деформацию корпуса гермозоны при перепадах атмосферного давления (например, в самолёте) и температуры, а также при прогреве устройства во время работы.

Пылинки, оказавшиеся при сборке в гермозоне и попавшие на поверхность диска, при вращении сносятся на ещё один фильтр — пылеуловитель.

The head block is a package of brackets (levers) made of aluminum-based alloys that combine light weight and high rigidity (usually a pair for each disk). At one end, they are fixed on an axis near the edge of the disk. At the other ends (above the discs), heads are fixed .

Disks (plates) are usually made of metal alloy. Although there were attempts to make them of plastic and even glass (IBM), but such plates were fragile and short-lived. Both planes of the plates, like a tape, are covered with the finest dust of a ferromagnet - oxides of iron , manganese and other metals. The exact composition and application technology is a trade secret . Most budget devices contain one or two plates, but there are models with a larger number of plates.

Disks are firmly mounted on the spindle. During operation, the spindle rotates at a speed of several thousand revolutions per minute (from 3600 to 15 000). At this speed, a powerful air stream is created near the surface of the plate, which raises the heads and makes them soar above the surface of the plate. The shape of the heads is calculated so that during operation to ensure the optimal distance from the plate. While the discs are not accelerated to the speed necessary for the heads to “take off”, the parking device keeps the heads in the parking zone . This prevents damage to the heads and the working surface of the plates. Hard disk spindle motor - valve motor .

Separator (separator) - a plate made of plastic or aluminum, located between the plates of the magnetic disks and above the upper plate of the magnetic disk. It is used to equalize the air flow inside the containment zone.

Positioning Device

 
Disassembled hard drive. The stator plate of the solenoid motor is removed

The head positioning device ( jarg. Actuator ) is a low inertia solenoid motor. It consists of a fixed pair of strong neodymium permanent magnets , as well as a coil (solenoid) on the movable bracket of the head block. The engine, together with the reading and processing system of the servo information recorded on the disk and the controller (VCM controller) forms a servo drive .

The head positioning system can be two-wheel drive. In this case, the main electromagnetic drive moves the unit with normal accuracy, and an additional piezoelectric mechanism combines the heads with the magnetic track with increased accuracy.

The principle of operation of the motor is as follows: the winding is located inside the stator (usually two fixed magnets), the current supplied with different strengths and polarity makes it accurately position the bracket (rocker) with heads along a radial path. The speed of data search on the surface of the plates depends on the speed of the positioning device.

Each drive has a special zone called a parking zone - it is on it that the heads stop at those moments when the drive is turned off or is in one of the low power consumption modes. In the parking state, the bracket (rocker) of the head block is in the extreme position and abuts against the travel limiter. In operations of access to information (read / write), one of the noise sources is vibration due to impacts of the brackets holding the magnetic heads against the stroke limiters in the process of returning the heads to the zero position. To reduce noise, soft rubber damping washers are installed on the travel stops. Significantly reduce the noise of the hard disk can be programmed by changing the parameters of the acceleration and braking of the head block. For this, a special technology is developed - Automatic Acoustic Management . Officially, the ability to programmatically control the noise level of a hard disk appeared in the ATA / ATAPI-6 standard (for this you need to change the value of the control variable), although some manufacturers have done experimental implementations before.

Electronics Block

In the early hard drives, the control logic was transferred to the MFM - or RLL-controller of the computer, and the electronics board contained only modules for analog processing and control of the spindle motor, positioner and switch heads. The increase in data transfer speeds forced developers to reduce the length of the analog path to the limit, and in modern hard disks the electronics block usually contains: a control unit, read-only memory (ROM), buffer memory, an interface unit and a digital signal processing unit .

The interface unit allows the electronics of the hard drive to interface with the rest of the system.

The control unit is a control system that receives electrical signals for positioning the heads and generates control actions by a “ voice coil ” drive, switching information flows from various heads, controlling the operation of all other nodes (for example, controlling the spindle speed), receiving and processing signals from device sensors (the sensor system may include a uniaxial accelerometer that is used as the shock sensor, a triaxial accelerometer , used in qual TBE free fall sensor, pressure sensor, angular acceleration sensor).

The ROM unit stores control programs for control units and digital signal processing, as well as service information of the hard drive.

The buffer memory smooths the difference in the speeds of the interface part and the drive (high-speed static memory is used ). Increasing the size of the buffer memory in some cases can increase the speed of the drive.

The digital signal processing unit cleans the read analog signal and decodes it (extracts digital information). Various methods are used for digital processing, for example, the PRML method (Partial Response Maximum Likelihood - maximum likelihood with an incomplete response). The received signal is compared with the samples. In this case, a sample is selected that is most similar in form and time characteristics to the decoded signal.

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    Macro photo of the magnetic head, bottom mirror reflection from the surface of the magnetic disk

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    Microphoto magnetic head

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    Parked magnetic head

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    Controller Board on Fujitsu's 3.5 "73GB SAS Drive

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    Mechanical and electrical components of the magnetic drive

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    The consequence of touching the surface of the disk with a magnetic head

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    A controller is required to connect the MFM drive to the motherboard

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    Controller board on an old IDE drive

Production

The production process for hard drives consists of several stages:

  • Aluminum alloy enters the Machining Zone in the form of long cylindrical blanks.
  • Blanks are cut from the blanks. Next, the workpiece is cut with the necessary exact dimensions and the bevels are machined.
  • Next, on a flat polishing machine, the work surfaces of the workpieces are polished to the desired cleanliness.
  • The blanks are cleaned, put into cassettes and moved to the Inspection and Transportation Zone (this zone has a purity class of 100), where the blanks are monitored.

For magnetic coating, the workpieces are moved to the magnetic coating zone (located inside the test zone, it has class 10).

  • An automatic galvanic line for applying multilayer coatings is installed there. The work is performed by robots under the control of the operator.

After the magnetic coating process is completed, the disks are placed in cassettes and again moved to the Inspection Zone.

  • The cassettes with disks go along the conveyor to the certifier , which is a rather large (the largest in the workshop) unit that has several spindles and a system for automatically installing disks from the cassettes. The certifier also has heads for writing and reading disks installed on the spindles. Discs are formatted in one long sector for the entire track. When reading, defects are detected that are entered into the database.
  • Proven pancakes are placed in cassettes and sent to the warehouse.

Manufacturers

Initially, the market had a wide variety of hard drives produced by many companies . Due to the toughening of competition, rapid growth of capacity, requiring modern technology, and lowering profit margins, most manufacturers were either bought by competitors or switched to other types of products.

In the mid -1990s, Conner Peripherials existed, which was subsequently bought by Seagate. Micropolis existed in the first half of the 1990s, producing very expensive premium SCSI drives for servers. But with the release of the industry's first 7200 rpm hard drives. she used substandard spindle bearings supplied by Nidec, and Micropolis suffered fatal losses on returns, went bankrupt and was completely redeemed by Seagate. Hard drives were also released by NEC .

Fujitsu continues to produce laptop hard drives and SCSI drives , but left the mass market for desktop drives in 2001 due to a massive failure of the Cirrus Logic controller chip (poor quality flux corroded rations). Prior to this, Fujitsu hard drives were considered [by whom? ] the best in the desktop sector , having excellent characteristics of rotating surfaces, with virtually no sectors reassigned to the plant. In 2009, the production of hard drives was completely transferred to Toshiba [31] .

The IBM division, whose disks until now were considered almost standard, after the fatal failures associated with the mass failures of disks for desktop computers in the early 2000s (the contacts of the failed German bank connector were oxidized) were bought by Hitachi in 2002 [32] .

Quantum left a fairly vivid trace in the history of hard drives, but it also failed in the early 2000s, even more tragic than IBM and Fujitsu: in the Quantum CX series hard drives, the head switch chip located in the drive's german bank failed, which led to a very expensive data extraction from a failed disk.

One of the leaders in disk production was Maxtor . In 2001, Maxtor bought the Quantum hard drive division and also did not escape reputation problems due to the so-called “thin” drives. In 2006, Maxtor was acquired by Seagate [32] .

In the spring of 2011, Western Digital acquired Hitachi production (3.5-inch drive plants were transferred to Toshiba in 2012) [33] [34] [35] ; at the same time, Samsung sold its HDD division to Seagate [36] [37] .

Since 2012, there are three main manufacturers left - Seagate , Western Digital and Toshiba [38] [39] .

Hard Market

Thailand Flood Impact 2011

The floods in Thailand in 2011 were flooded hard drive factories Western Digital , Seagate Technology , Hitachi and Toshiba . According to IDC , this has led to a drop in hard drive production by a third [40] . According to Piper Jaffray, in the IV quarter of 2011 the deficit of hard drives in the world market will amount to 60-80 million units with a volume of demand of 180 million, as of November 9, 2011, prices for hard drives have already risen from 10 to 60% [ 41] .

On December 1, 2011, Western Digital reported on restoration work in Thailand and offered its assessment of the state of the hard drive industry in the fourth quarter of 2011 and beyond [42] .

Cost

Since the start of hard drive production in 1956, their price has dropped from tens of thousands of dollars to tens of dollars in the mid-2010s. The cost of capacity decreased from 9200 to $ 0.000035 per megabyte [43] .

Low Level Formatting

At the final stage of assembly of the device, the surfaces of the plates are formatted - tracks and sectors are formed on them. The specific method is determined by the manufacturer and / or standard, but at least a magnetic mark is applied to each track, indicating its beginning.

There are utilities that can test the physical sectors of a disk and view and edit its service data to a limited extent [44] . The specific capabilities of such utilities strongly depend on the disk model and technical information known to the software author of the corresponding model family [45] .

Disk geometry

 

For the purpose of addressing, the surface space of the disk plates is divided into tracks - concentric annular regions. Each track is divided into equal segments - sectors . CHS addressing assumes that all tracks in a given area of ​​a disc have the same number of sectors.

A cylinder is a set of tracks equally spaced from the center on all working surfaces of the hard drive plates. The head number defines the working surface used, and the sector number the specific sector on the track.

To use CHS addressing, you need to know the geometry of the disk used: the total number of cylinders, heads and sectors in it. Initially, this information was required to be set manually; in the ATA -1 standard, the function of automatic geometry detection was introduced (the Identify Drive command) [46] .

The Impact of Geometry on Disk Speed

The geometry of the hard disk affects the read / write speed. Closer to the outer edge of the disk plate, the length of the tracks increases (more sectors fit, the number of sectors on the cylinders previously was the same) and, accordingly, the amount of data that the device can read or write in one revolution. In this case, the reading speed can vary from 210 to 30 MB / s. Knowing this feature, it is advisable to place the root sections of operating systems here. Sector numbering starts from the outer edge of the disk from scratch.

Geometry Features of Hard Drives with Integrated Controllers

Zoning

On the plates of modern "hard drives", tracks are grouped into several zones ( English Zoned Recording ). All tracks in the same zone have the same number of sectors. However, there are more sectors on the tracks of the external zones than on the tracks of the internal ones. This allows using a longer external track to achieve a more uniform recording density, increasing the capacity of the plate with the same production technology.

Reserve Sectors

To increase the life of the disc, additional backup sectors may be present on each track. If an unrecoverable error occurs in any sector, then this sector can be replaced by a reserve one ( English remapping ). The data stored in it can be lost or restored using ECC , and the disk capacity will remain the same. There are two reassignment tables: one is populated at the factory, the other during operation. The boundaries of the zones, the number of sectors per track for each zone and the sector reassignment table are stored in the ROM of the electronics unit.

Logical Geometry

As the capacity of manufactured hard disks grows, their physical geometry no longer fits into the restrictions imposed by software and hardware interfaces (see: Hard disk capacity). In addition, tracks with a different number of sectors are not compatible with the CHS addressing method. As a result, disk controllers began to report not real, but fictitious, logical geometry , which fits into the limitations of the interfaces, but does not correspond to reality. So, the maximum sector and head numbers for most models are taken 63 and 255 (the maximum possible values ​​in the BIOS INT 13h BIOS interrupt functions), and the number of cylinders is selected according to the disk capacity. The physical geometry of the disk itself cannot be obtained in the normal mode of operation [47] and is not known to other parts of the system.

Data Addressing

Минимальной адресуемой областью данных на жёстком диске является сектор . Размер сектора традиционно равен 512 байт [48] . В 2006 году IDEMA объявила о переходе на размер сектора 4096 байт, который планируется завершить к 2010 году [49] .

Компания Western Digital уже сообщила [50] о начале использования новой технологии форматирования, названной Advanced Format , и выпустила серию накопителей, использующих новую технологию. К этой серии относятся линейки AARS/EARS и BPVT.

Перед использованием накопителя с технологией Advanced Format для работы в Windows XP необходимо выполнить процедуру выравнивания раздела(ов) с помощью специальной утилиты [51] . Если разделы на диске создаются Windows Vista , Windows 7 и Mac OS , выравнивание не требуется. [52]

В Windows Vista, Windows 7, Windows Server 2008 и Windows Server 2008 R2 присутствует ограниченная поддержка дисков с увеличенным размером сектора [53] [54] .

Существует два основных способа адресации секторов на диске:

  • цилиндр-головка-сектор ( англ. cylinder-head-sector, CHS );
  • линейная адресация блоков ( англ. linear block addressing, LBA ).

CHS

При этом способе сектор адресуется по его физическому положению на диске тремя координатами — номером цилиндра , номером головки и номером сектора . В дисках объёмом больше 528 482 304 байт (504 МБ) со встроенными контроллерами эти координаты уже не соответствуют физическому положению сектора на диске и являются «логическими координатами» (смотри выше ).

LBA

При этом способе адрес блоков данных на носителе задаётся с помощью логического линейного адреса. LBA-адресация начала внедряться и использоваться в 1994 году совместно со стандартом EIDE (Extended IDE). Необходимость LBA была вызвана, в частности, появлением дисков больших объёмов , которые нельзя было полностью использовать с помощью старых схем адресации.

LBA=((Cylinder×Noofheads+heads)×sectors/track)+(Sector-one){\displaystyle \mathrm {LBA} ={\bigl (}(\mathrm {Cylinder} \times \mathrm {No\ of\ \mathrm {heads} } +\mathrm {heads} )\times \mathrm {sectors/track} {\bigr )}+(\mathrm {Sector} -1)}  

Метод LBA соответствует Sector Mapping для SCSI . BIOS SCSI-контроллера выполняет эти задачи автоматически, то есть для SCSI-интерфейса метод логической адресации был характерен изначально.

Сравнение интерфейсов

Пропускная способность, Гбит/сМаксимальная длина кабеля, мТребуется ли кабель питанияКоличество накопителей на каналЧисло проводников в кабелеДругие особенности
Ultra ATA /1331,20.46Да (3,5") / Нет (2,5")240/80Controller+2Slave, горячая замена невозможна
SATA -3002,4oneYesone7Host/Slave, возможна горячая замена на некоторых контроллерах
SATA -6004.8no dataYesone7
FireWire /4000.44,5 (до 72 м при последовательном соединении)Да/Нет (зависит от типа интерфейса и накопителя)634/6устройства равноправны, горячая замена возможна
FireWire /8000.84,5 (до 72 м при последовательном соединении)Да/Нет (зависит от типа интерфейса и накопителя)639устройства равноправны, горячая замена возможна
USB 2.00,48

(реально — 0,25)

5 (до 72 м при последовательном соединении через хабы )Да/Нет (зависит от типа накопителя)127fourHost/Slave, горячая замена возможна
USB 3.04.8no dataДа/Нет (зависит от типа накопителя)no data9Двунаправленный, совместим с USB 2.0
Ultra-320 SCSI2,5612Yessixteen50/68устройства равноправны, горячая замена возможна
SAS2,4eightYesСвыше 16384горячая замена; возможно подключение SATA -устройств в SAS-контроллеры
eSATA2,42Yes1 (до 15 с умножителем портов)7Host/Slave, горячая замена возможна

История прогресса

 
Шесть типоразмеров жёстких дисков. Рядом лежит дюймовая линейка
  • 1956 год — жёсткий диск IBM 350 в составе первого серийного компьютера IBM 305 RAMAC. Накопитель занимал ящик размером с большой холодильник и имел вес 971 кг, а общий объём памяти 50 вращавшихся в нём покрытых чистым железом тонких дисков диаметром 610 мм составлял около 5 млн 6-битных слов (3,5 МБ в пересчёте на 8-битные слова — байты ).

Во времена создания первых жёстких дисков у IBM существовало правило: все модели должны были проходить через стандартный дверной проём в 75 см [55] .

  • 1961 год — в жёстком диске IBM 1301 головки чтения/записи впервые были установлены для каждого диска; 28 МБ [56] .
  • 1973 год — в жёстком диске IBM 3340 , названном Winchester, впервые были применены лёгкие головки чтения/записи, парящие над вращающимся диском под действием аэродинамических сил, что позволило значительно уменьшить воздушный зазор между диском и головкой. Также впервые пластины и головки были упакованы в гермокамеры, что исключило внешние воздействия на механизм; 30 МБ [57] .
  • 1979 год — в жёстком диске IBM 3370 впервые магнитные головки были изготовлены по тонкоплёночной технологии, разрабатываемой с конца 1960-х годов. Благодаря этому плотность записи увеличилась до 7,53 Мбит на дюйм. Тонкоплёночные головки чтения/записи производились до 1991 года, после чего их заменили магниторезистивные головки [58] .
  • 1980 год — первый 5,25-дюймовый Winchester, Shugart ST-506 ; 5 МБ (промышленные накопители IBM достигали ёмкости в 1 ГБ [58] ). Жёсткие диски типоразмера 5,25" производились до 1998 года [59] .
  • 1981 год — 5,25-дюймовый Shugart ST-412 ; 10 МБ [58] .
  • 1983 год — первый 3,5-дюймовый жёсткий диск, выпущенный небольшой шотландской компанией Rodime ; 10 МБ. Данный форм-фактор был запатентован Rodime как собственное изобретение [59] .
  • 1985 год — стандарт ESDI , доработанный стандарт ST-412 .
  • 1986 год — стандарты SCSI , ATA (IDE).
  • 1990 год — максимальная ёмкость 320 МБ.
  • 1991 год — IBM выпускает первый 2,5-дюймовый жёсткий диск Tamba-1 ёмкостью 63 МБ и весом чуть более 200 грамм [59] .
  • 1992 год — первый жёсткий диск со скоростью вращения шпинделя 7200 об./мин.; 2,1 ГБ [59] .
  • 1995 год — максимальная ёмкость 2 ГБ.
  • 1996 год — первый жёсткий диск со скоростью вращения шпинделя 10 000 об./мин., Seagate Cheetah [60] .
  • 1997 год — максимальная ёмкость 10 ГБ.
  • 1998 год — стандарты UDMA/33 и ATAPI .
  • 1999 год — IBM выпускает Microdrive ёмкостью 170 и 340 МБ.
  • 2000 год — IBM выпускает Microdrive ёмкостью 500 МБ и 1 ГБ. В этом же году появились первые жёсткие диски со скоростью вращения шпинделя 15 000 оборотов в минуту, выпущенные Seagate и IBM. На этом гонка скоростей вращения прекратилась [61] .
  • 2002 год — стандарт ATA/ATAPI-6 и накопители ёмкостью свыше 137 ГБ.
  • 2003 год — появление SATA .
  • 2003 год — Hitachi выпускает Microdrive ёмкостью 2 ГБ.
  • 2004 год — Seagate выпускает ST1 — аналог Microdrive ёмкостью 2,5 и 5 ГБ.
  • 2005 год — максимальная ёмкость 500 ГБ.
  • 2005 год — стандарты Serial ATA 3G (или SATA II) и SAS (Serial Attached SCSI).
  • 2005 год — Seagate выпускает ST1 — аналог Microdrive ёмкостью 8 ГБ.
  • 2006 год — применение перпендикулярного метода записи в коммерческих накопителях.
  • 2006 год — появление первых «гибридных» жёстких дисков, содержащих блок флеш-памяти .
  • 2006 год — Seagate выпускает ST1 — аналог Microdrive ёмкостью 12 ГБ.
  • 2007 год — Hitachi представляет первый коммерческий накопитель ёмкостью 1 ТБ .
  • 2009 год — на основе 500-гигабайтных пластин Western Digital , затем Seagate выпустили модели ёмкостью 2 ТБ [62] .
  • 2009 год — Samsung выпустила первые жёсткие диски с интерфейсом USB 2.0 [63] .
  • 2009 год — Western Digital объявила о создании 2,5-дюймовых HDD объёмом 1 ТБ (плотность записи — 333 ГБ на одной пластине) [64] .
  • 2009 год — появление стандарта SATA 3.0 (SATA 6G).
  • 2010 год — Seagate выпускает жёсткий диск объёмом 3 ТБ.
  • 2010 год — Samsung выпускает жёсткий диск с пластинами, у которых плотность записи — 667 ГБ на одной пластине [65] .
  • 2011 год — Western Digital выпустила первый диск на 750-гигабайтных пластинах [66] .
  • 2011 год — Hitachi и Seagate выпустили диски на 1-терабайтных пластинах [67] [68] .
  • 2011 год — Seagate представила первый в мире 3,5-дюймовый диск объёмом 4 ТБ [69] [70] .

Плотность записи на жёстких дисках за 50 лет (с 1961 по 2011 год) увеличилась в 60 млн раз [59] .

  • 2013 год — Western Digital выпускает диск на 6 ТБ с 7 пластинами вместо 5 [71] .
  • 2014 год — Western Digital выпустила первый в мире диск на 10 ТБ с гелием вместо воздуха внутри корпуса. Имеет 7 пластин [72] [73] .
  • 2017 год — Toshiba выпустила диск «MG07ACA», ёмкость которого составляет 14 ТБ [74] .
  • 2018 год — Компания Seagate заявила о создании жёсткого диска объёмом 16 ТБ [75]

Неисправности

  • Окисление дорожек платы диска.
  • Повреждение магнитной головки при чтении.

Для жёстких дисков характерны высокая надёжность работы и хранения информации. Они могут проработать десятки лет. Их обычно заменяют, чтобы купить HDD большей ёмкости задолго до выхода из строя старого диска.

See also

  • Advanced Host Controller Interface
  • NCQ
  • Раздел диска
  • Список компаний, производивших жёсткие диски
  • Объём жёсткого диска
  • Внешний жёсткий диск

Notes

  1. ↑ Reference Guide — Hard Disk Drives (англ.) . Дата обращения 28 июля 2009. Архивировано 23 августа 2011 года.
  2. ↑ http://www.storagereview.com/guide/histEarly.html Reference Guide — Hard Disk Drives — Early Disk Drives (англ.)
  3. ↑ IBM Archives: IBM 3340 direct access storage facility
  4. ↑ Жёсткий диск или винчестер? Архивная копия от 20 июня 2010 на Wayback Machine
  5. ↑ Словарь русского арго. — ГРАМОТА.РУ. В. С. Елистратов. 2002.
  6. ↑ Timeline: 50 Years of Hard Drives
  7. ↑ Nanoelectronics and Photonics , p. 82.
  8. ↑ 2,4 Тбит на квадратный дюйм к 2014 году // 3DNews , 08.06.2009
  9. ↑ 17 августа в истории… революционные винчестеры Архивная копия от 18 августа 2015 на Wayback Machine // Ferra.ru
  10. ↑ Иллюстрация Western Digital с прогнозом по снижению стоимости терабайта в HDD и SSD ( Western Digital Stuns Storage Industry with MAMR Breakthrough for Next-Gen HDDs — Anandtech, October 12, 2017 (англ.) )
  11. ↑ Chip , 2012, № 11, с. 116.
  12. ↑ Технология SMR открывает новые горизонты магнитной записи КомпьютерПресс 12'2013.
  13. ↑ TDK освоила 1 терабит на квадратный дюйм , 3DNews , 07.10.2009.
  14. ↑ Д. Анисимов, Е. Патий. Индустрия жёстких дисков: дальше — больше // «Экспресс электроника». — 2007. — № 3.
  15. ↑ S. Schlauderer, C. Lange, S. Baierl, T. Ebnet, CP Schmid, DC Valovcin, AK Zvezdin, AV Kimel, RV Mikhaylovskiy & R. Huber. Temporal and spectral fingerprints of ultrafast all-coherent spin switching // NATURE : Letter. — 2019. — 15 май ( т. 569 , № 569 ). — С. 383–387 .
  16. ↑ https://www.sciencedaily.com/releases/2019/05/190515131745.htm
  17. ↑ https://ria.ru/20190515/1553520085.html
  18. ↑ https://mipt.ru/newsblog/lenta/uchenye_sozdali_prototip_superenergoeffektivnoy_pamyati_budushchego
  19. ↑ 2016 Hard Drive Review: Testing 61,590 Hard Drives / Backblaze
  20. ↑ В спецификации диска Medalist 545xe (Seagate ST3660A) заявлены параметры: форматированный объём 545,5 Мб и геометрия 1057 цилиндров × 16 головок × 63 сектора × 512 байт в секторе = 545 513 472 байт. Однако заявленный объём 545,5 из геометрии получается только если её поделить на 1000×1000; при делении на 1024×1024 получается значение 520,2. Medalist 545XE (англ.) (недоступная ссылка) . Seagate (17 August 1994). Дата обращения 8 декабря 2008. Архивировано 9 мая 2008 года.
  21. ↑ Другой пример: заявлен объём 320 Гб и количество доступных секторов 625 142 448 . Однако если количество секторов умножить на их размер (512), то в результате получится 320 072 933 376 . «320» отсюда получаются только делением на 1000³, при делении на 1024³ получается только 298. Barracuda 7200.9 320 GB PATA hard drive (ST3320833A) (англ.) . Seagate. — закладка Technical Specifications. Дата обращения 8 декабря 2008. Архивировано 23 августа 2011 года.
  22. ↑ База знаний Seagate. Стандарты измерения ёмкости запоминающего устройства
  23. ↑ https://courses.cs.washington.edu/courses/cse378/10sp/lectures/lec26.pdf
  24. ↑ logo-symantec-dark-source
  25. ↑ News, Tips, and Advice for Technology Professionals — TechRepublic
  26. ↑ SSD Throughput, Latency and IOPS Explained — Learning To Run With Flash | The SSD Review
  27. ↑ http://dataidol.com/tonyrogerson/2014/04/07/maximum-iops-for-a-10k-or-15k-sas-hard-disk-drive-is-not-170/
  28. ↑ Hard Disk Drive: Mechatronics and Control , p21
  29. ↑ Best internal hard drives 2018: The best high-capacity HDDs to buy from £100 | Expert Reviews
  30. ↑ Обзор Scythe Quiet Drive
  31. ↑ New Operating Structure for Toshiba's HDD Business
  32. ↑ 1 2 UPgrade №4, 2011 , с. 25.
  33. ↑ Пресс-релиз HGST // Western Digital (англ.)
  34. ↑ Western Digital покупает Hitachi (неопр.) (недоступная ссылка) . Upgrade Special (9 марта 2011). Дата обращения 17 марта 2015. Архивировано 2 апреля 2015 года.
  35. ↑ Минус один // UPgrade : журнал. — 2011. — № 10 (514) . — С. 7 . — ISSN 1680-4894 .
  36. ↑ Компании Seagate и Samsung объявили о широкомасштабном согласовании стратегий (неопр.) . Новости Seagate (19 апреля 2011). Дата обращения 2 июля 2015.
  37. ↑ Компания Seagate завершает приобретение направления жёстких дисков компании Samsung (неопр.) . Новости Seagate (19 декабря 2011). Дата обращения 2 июля 2015.
  38. ↑ Why are some hard drives more reliable than others? // ExtremeTech, September 23, 2014
  39. ↑ How Three Hard Drive Companies Gobbled Up The Industry
  40. ↑ Жесткие диски подорожали // UPgrade : журнал. — 2011. — 31 октября ( № 42 ). — С. 31 . — ISSN 1680-4694 .
  41. ↑ Эксперты: дефицит жёстких дисков только усилится (неопр.) . Вести.ru (9 ноября 2011). Дата обращения 9 ноября 2011. Архивировано 3 февраля 2012 года.
  42. ↑ WD представила обновленный прогноз финансовых показателей на четвёртый квартал и отчёт о работах по восстановлению производства в Таиланде Архивная копия от 21 января 2012 на Wayback Machine — Пресс-релиз
  43. ↑ Disk Drive Prices (1955—2014) (англ.) . Дата обращения 10 января 2015. Архивировано 14 июля 2015 года.
  44. ↑ Коллекция утилит для низкоуровневой диагностики и ремонта жёстких дисков (неопр.) . Archived August 23, 2011.
  45. ↑ Утилита диагностики и ремонта жёстких дисков UDMA-3000 с модулями для множества моделей (неопр.) . Archived August 23, 2011.
  46. ↑ X3T10 791D Revision 4c Working Draft (англ.) . American National Standard for Information Technology — AT Attachment Interface for Disk Drives . Technical Committee of the International Committee on Information Technology Standards. — Черновик стандарта ANSI X3.221 — 199x. Дата обращения 16 апреля 2012. (недоступная ссылка)
  47. ↑ В спецификациях АТА и SCSI отсутствуют команды для этого
  48. ↑ Во всех серийно используемых стандартах, начиная с ST-506 /ST-412, разработанного в начале 1980-х годов.
  49. ↑ IDEMA Announces a New Sector Length Standard (неопр.) .
  50. ↑ The page is no longer available Архивная копия от 11 июля 2010 на Wayback Machine
  51. ↑ WD Align Tool
  52. ↑ Product Features Архивная копия от 19 сентября 2014 на Wayback Machine
  53. ↑ Windows Vista support for large-sector hard disk drives (англ.) . Microsoft (29 May 2007). Дата обращения 14 апреля 2011. Архивировано 23 августа 2011 года.
  54. ↑ Information about Microsoft support policy for large sector drives in Windows (англ.) . Microsoft (4 March 2011). Дата обращения 14 апреля 2011. Архивировано 23 августа 2011 года.
  55. ↑ UPgrade № 4, 2011 , с. 20.
  56. ↑ UPgrade № 4, 2011 , с. 21.
  57. ↑ UPgrade № 4, 2011 , с. 21—22.
  58. ↑ 1 2 3 UPgrade № 4, 2011 , с. 22.
  59. ↑ 1 2 3 4 5 UPgrade № 4, 2011 , с. 23.
  60. ↑ UPgrade № 4, 2011 , с. 23—24.
  61. ↑ UPgrade № 4, 2011 , с. 24.
  62. ↑ Выпущен двухтерабайтный винчестер Лента.ру
  63. ↑ Samsung: 1.8" Spinpoint N3U HDD With Native USB (англ.)
  64. ↑ Western Digital Releases 1TB 2.5-inch Laptop Hard Drive (англ.)
  65. ↑ Новости Hardware | Новости и статьи | Ф-Центр
  66. ↑ Новый виток эволюции: 3-ТБ жёсткие диски
  67. ↑ Hitachi начинает выпуск жёстких дисков ёмкостью 1 ТБ с одной пластиной
  68. ↑ журнал «Компьютерная газета Хард Софт» 7/2013, стр.15
  69. ↑ 4 внешних терабайта // UPgrade : журнал. — 2011. — 19 сентября ( № 36 ). — С. 43 . — ISSN 1680-4694 . Архивировано 20 августа 2016 года.
  70. ↑ Seagate представила жёсткий диск ёмкостью 4 Тб
  71. ↑ Digital enlists helium for 6TB energy-efficient drives
  72. ↑ Western Digital выпустила первую в мире 10-терабайтную модель HDD с гелием вместо воздуха (неопр.) .
  73. ↑ Western Digital unveils world's first 10TB hard drive: Helium-filled, shingled recording
  74. ↑ Объем жесткого диска Toshiba MG07ACA — 14 ТБ (рус.) , iXBT.com . Date of treatment December 20, 2017.
  75. ↑ Cal Jeffrey. Seagate announces "world's first" 16TB 3.5-inch hard drive (англ.) (неопр.) ? . https://www.techspot.com (3.12.2018).

Literature

  • Мюллер С. Модернизация и ремонт ПК = Upgrading and Repairing PCs / Скотт Мюллер. — 17-е изд. — М. : Вильямс , 2007. — С. 653—700. — ISBN 0-7897-3404-4 .
  • Евгений aka Saturn. История магнитного складирования // UPgrade : журнал. — 2011. — № 4 (508) . — С. 20—25 . — ISSN 1680-4694 .

Links

  • Энциклопедия жёстких дисков
  • 50 лет жёстким дискам // iXBT
  • Работа жёсткого диска (видео)
  • Performance comparison of SSD and HDD // PC-hard.ru. - 2012.
  • Andrianov S. Basic information about hard drives / Sergey Andrianov // MorePC. - 2002. - July 21. (Retrieved September 7, 2014)
  • Vishnyakova N. Device and principle of operation of the hard disk / Natalya Vishnyakova // Computer from scratch. - 2012 .-- March 26. (Retrieved September 7, 2014)
Источник — https://ru.wikipedia.org/w/index.php?title=Жёсткий_диск&oldid=101549971


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