Hard drive on this computer là gì
What is a hard disk drive?
A computer hard disk drive (HDD) is a non-volatile data storage device. Non-volatile refers to storage devices that maintain stored data when turned off. All computers need a storage device, và HDDs are just one example of a type of storage device.
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HDDs are usually installed inside desktop computers, thiết bị di động devices, consumer electronics and enterprise storage arrays in data centers. They can store operating systems, software programs và other files using magnetic disks.
More specifically, hard disk drives control the reading and writing of the hard disk that provides data storage. HDDs are used either as the primary or secondary storage device in a computer. They are commonly found in the drive bay and are connected lớn the motherboard via an Advanced giải pháp công nghệ Attachment (ATA), Serial ATA, parallel ATA or Small Computer System Interface (SCSI) cable, among other formats. The HDD is also connected to lớn a nguồn supply unit & can keep stored data while powered down.
A hard disk drive -- often shortened to hard drive -- và hard disk are not the same things, but they are packaged as a unit & either term can refer to the whole unit.
Why do computers need hard disks?
Storage devices lượt thích hard disks are needed to lớn install operating systems, programs và additional storage devices, and to save documents. Without devices lượt thích HDDs that can retain data after they have been turned off, computer users would not be able to store programs or save files or documents to lớn their computers. This is why every computer needs at least one storage device khổng lồ permanently hold data as long as it is needed.
How vì chưng hard disk drives work?
Most basic hard drives consist of several disk platters -- a circular disk made of either aluminum, glass or ceramic -- that are positioned around a spindle inside a sealed chamber. The platter spins with a motor that is connected lớn the spindle. The chamber also includes the read/write heads that magnetically record information to and from tracks on the platters using a magnetic head. The disks also have a thin magnetic coating on them.
The motor spins the platters at up to 15,000 rotations per minute. As the platters spin, a second motor controls the position of the read & write heads that magnetically record and read information on each platter.
Hard disk drive storage capacity
Some of the most common storage drive capacities include the following:
120 GB & 256 GB. This range is generally considered an entry point for HDD devices such as laptops or computers. 500 GB, 1 TB & 2 TB. Around 500 GB and above of HDD storage is typically considered decent for an average user. Users can most likely store all their music, photos, videos and other files with this much space. Individuals with games that take up a lot of space should find 1 TB lớn 2 TB of HDD space suitable. More than 2 TB. Anything over 2 TB of HDD space is suitable for users who work with high-resolution files, who need to store or house a large amount of data, or who want lớn use that space for backup & redundancy.Currently, the highest capacity HDD is 20 TB. However, an HDD actually has less space than advertised, as the operating system, tệp tin system structures và some data redundancy procedures use a portion of that space.
Hard drive components & form factors
Hard disk drive components include the spindle, disk platter, actuator, actuator arm & read/write head. Even though the term can refer to the unit as a whole, the term hard disk is the phối of stacked disks -- in other words, the part of the HDD that stores và provides access khổng lồ data on an electromagnetically charged surface.
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The HDD form factor refers khổng lồ the physical kích thước or geometry of the data storage device. HDD khung factors follow a phối of industry standards that govern their length, width and height, as well as the position và orientation of the host interface connector. Having an industry-standard size factor helps determine a common compatibility with different computing devices.
The most common size factors for HDDs in enterprise systems are 2.5-inch & 3.5-inch -- also known as small form factor (SFF) & large size factor (LFF). The 2.5-inch và 3.5-inch measurements represent the approximate diameter of the platter within the drive enclosures.
While there are other form factors, by 2009, manufacturers discontinued the development of products with 1.3-inch, 1-inch & 0.85-inch form factors. The falling price of flash made these other form factors almost obsolete. It is also important to lưu ý that while nominal sizes are in inches, actual dimensions are specified in millimeters.
Many solid-state drives (SSDs) are also designed for the HDD form factor. SSDs that fit into the same slots as HDDs generally use the SATA or serial-attached SCSI (SAS) interface to transfer data to & from the host computing system.
What are external HDDs?
Most HDDs are found internally in a computer & work as stated above. However, individuals can also purchase external hard drives. External hard drives can be used to expand the storage capacity of a computer or lớn act as a portable device to lớn back up data. External drives connect khổng lồ a computer or device through interfaces lượt thích USB 2.0, USB-C or with External SATA (eSATA). External hard drives may also have slower data transfer rates compared to internal HDDs.
The main advantage of an external hard drive, aside from being able khổng lồ expand a device"s storage space, includes being portable. Users can store data from multiple devices & physically bring that data with them wherever they go.
Common hard disk errors
Hard disks can fail for all sorts of reasons. However, failures generally fall into the following six broad categories.
Electrical failure occurs when, for example, a power nguồn surge damages a hard disk"s electronic circuitry, causing the read/write head or circuit board to fail. If a hard disk powers on but cannot read & write data or boot, it is likely that one or more of its components has suffered an electrical failure. Mechanical failure can be caused by wear and tear, as well as by a hard impact, like a hard drop. This may cause, among other things, the read/write drive head to hit a rotating platter, causing irreversible physical damage. Logical failure results when the hard disk"s software is compromised or ceases khổng lồ run properly. All sorts of data corruption can lead to lớn a logical failure. This includes corrupted files, malware and viruses, improperly closing an application or shutting down a computer, human error or accidentally deleting files that are critical lớn hard disk functionality. Bad sector failure can occur when the magnetic truyền thông media on a hard disk"s rotating platter is misaligned, resulting in a specific area on the platter becoming inaccessible. Bad sectors are common and often limited when they occur. Over time, however, the number of bad sectors can increase, eventually leading to a system crash, inaccessible files or the hanging or lagging of the operation of a hard disk. Firmware failure happens when the software that performs the maintenance tasks on a drive & enables the hard disk to communicate with a computer becomes corrupted or stops working properly. This type of failure can lead khổng lồ the disk freezing during bootup or the computer a hard disk is connected lớn not recognizing or misidentifying it. Multiple unknown failures that accumulate over time can also occur. For example, an electrical problem could lead to a mechanical failure, such as a read/write head crash. It might also lead to lớn a logical failure, resulting in several bad sectors developing on the hard disk platters.History of hard disk drives
The hard disk was created in 1953 by engineers at IBM who wanted khổng lồ find a way lớn provide random access to high capacities of data at a low cost. The disk drives developed were the kích thước of refrigerators, could store 3.75 MB of data & began shipping in 1956. Memorex, Seagate Technology và Western Digital were other early vendors of hard disk drive technology.
Hard disk drive form-factor size has continued khổng lồ decrease as the giải pháp công nghệ evolves. By the mid-1980s, 3.5-inch & 2.5-inch form factors were introduced and became a standard in personal computers.
Hard disk drive density has increased since the công nghệ was first developed. The first hard disk drives could store megabytes of data, while today their storage capacity is in the terabyte range. Hitachi Global Storage Technologies (HGST) -- now a Western Digital brand -- released the first 1 TB hard drives in 2007. In 2015, HGST announced the first 10 TB hard drive. And in 2021, Western Digital unveiled two 20 TB HDDs.
HDD evolution & technology developments
In 2013, Seagate giải pháp công nghệ announced hard disk drives that use shingled magnetic recording (SMR) technology. SMR increases storage density in hard disk drives by layering the magnetic tracks on each disk, rather than placing them parallel lớn each other. It is referred khổng lồ as shingled because the tracks overlap similar to lớn shingles on a roof.
