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Hard Disk Drive Failure
A hard disk drive failure occurs when a hard disk drive malfunctions and the stored information cannot be accessed with a properly configured computer. A hard disk failure may occur in the course of normal operation, or due to an external factor such as exposure to fire or water or high magnetic fields, or suffering a sharp impact (mechanics), impact or environmental contamination, which can lead to a head crash. The stored information on a hard drive may also be rendered inaccessible as a result of data corruption, disruption or destruction of the hard drive's master boot record, or by malware deliberately destroying the disk's contents. Causes There are a number of causes for hard drives to fail including: human error, hardware failure, firmware corruption, media damage, heat, water damage, power issues and mishaps. Drive manufacturers typically specify a mean time between failures (MTBF) or an annualized failure rate (AFR) which are population statistics that can't predict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanometers
330px, Different lengths as in respect to the molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American and British English spelling differences#-re, -er, American spelling), is a units of measurement, unit of length in the International System of Units (SI), equal to one billionth ( short scale) or one thousand million (long scale) of a meter (0.000000001 m) and to 1000 picometres. One nanometre can be expressed in scientific notation as 1 × 10−9 m and as m. History The nanometre was formerly known as the "''millimicrometre''" – or, more commonly, the "''millimicron''" for short – since it is of a micrometer. It was often denoted by the symbol ''mμ'' or, more rarely, as ''μμ'' (however, ''μμ'' should refer to a ''millionth'' of a micron). Etymology The name combines the SI prefix ''nano-'' (from the Ancient Greek , ', "dwarf") with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (device)
A spring is a device consisting of an Elasticity (physics), elastic but largely rigid material (typically metal) bent or molded into a form (especially a coil) that can return into shape after being compressed or extended. Springs can Energy storage, store energy when compressed. In everyday use, the term most often refers to coil springs, but there are many different spring designs. Modern springs are typically manufactured from spring steel. An example of a non-metallic spring is the Bow (weapon), bow, made traditionally of flexible Taxus baccata, yew wood, which when Bow draw, drawn stores energy to propel an arrow. When a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length (this approximation breaks down for larger deflections). The ''rate'' or ''spring constant'' of a spring is the change in the force it exerts, divided by the cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WD102AA Scratched Area Read Retries
''Watch Dogs'' is a 2014 action-adventure game developed by Ubisoft Montreal and published by Ubisoft. It is the first installment in the ''Watch Dogs'' series. The game is played from a third-person perspective, and its world is navigated on foot or by vehicle. Set within a fictionalized version of the Chicago metropolitan area in 2013, the single-player story follows grey hat hacker and vigilante Aiden Pearce's quest for revenge after the killing of his niece. An online multiplayer mode allows up to eight players to engage in cooperative and competitive gameplay. Development of the game began in 2009, and continued for over five years. Duties were shared by many of Ubisoft's studios worldwide, with more than a thousand people involved. The developers visited Chicago to conduct field research on the setting, and used regional language for authenticity. Hacking features were created in consultation with the cyber-security company Kaspersky Lab, and the in-game control system wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Click Of Death
Click of death is a term that had become common in the late 1990s referring to the clicking sound in disk storage systems that signals a disk drive has failed, often catastrophically. The clicking sound itself arises from the unexpected movement of the disk's read/write actuator. At startup, and during use, the disk head must move correctly and be able to confirm that it is correctly tracking data on the disk. If the head fails to move as expected or upon moving cannot track the disk surface correctly, the disk controller may attempt to recover from the error by returning the head to its home position and then retrying, at times causing an audible "click". In some devices, the process automatically retries, causing a repeated or rhythmic clicking sound, sometimes accompanied by the whirring sound of the drive plate spinning. Origin of the term The phrase "click of death" originated to describe a failure mode of the Iomega ZIP drives, appearing in print as early as January 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Hard-drive Defect Management
Internal hard drive defect management is a system present in hard drives for handling of bad sector Bad Sector is an ambient/noise project formed in 1992 in Tuscany, Italy by Massimo Magrini. While working at the Computer Art Lab of ISTI in Pisa (one of the CNR institutes), he developed original gesture interfaces that he uses in live pe ...s. The systems are generally proprietary and vary from manufacturer to manufacturer, but typically consist of a "P" (for "permanent" or "primary") list of bad sectors detected in the manufacturing stage and a "G" (for "growth") list of bad sectors that crop up after manufacturing. Many disk/controller subsystems reserve storage to remap defective disk sectors. The drive automatically creates its initial remapping information and has the additional ability to dynamically remap "grown" defects. Because the drive is remapping its own bad sectors, software may not detect growing numbers of bad sectors until later stages of gradual hard-disk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIOS POST
A power-on self-test (POST) is a process performed by firmware or software routines immediately after a computer or other digital electronic device is powered on. POST processes may set the initial state of the device from firmware and detect if any hardware components are non-functional. The results of the POST may be displayed on a panel that is part of the device, output to an external device, or stored for future retrieval by a diagnostic tool. In some computers, an indicator lamp or a speaker may be provided to show error codes as a sequence of flashes or beeps in the event that a computer display malfunctions. POST routines are part of a computer's pre-boot sequence. If they complete successfully, the bootstrap loader code is invoked to load an operating system. In IBM PC compatible computers, the main duties of POST are handled by the BIOS or UEFI. IBM-compatible PC POST In IBM PC compatible computers, the main duties of POST are handled by the BIOS or UEFI, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CMOS Setup
Nonvolatile BIOS memory refers to a small memory on PC motherboards that is used to store BIOS settings. It is traditionally called CMOS RAM because it uses a volatile, low-power complementary metal–oxide–semiconductor (CMOS) SRAM (such as the Motorola MC146818 or similar) powered by a small battery when system and standby power is off. It is referred to as non-volatile memory or NVRAM because, after the system loses power, it does retain state by virtue of the CMOS battery. When the battery fails, BIOS settings are reset to their defaults. The battery can also be used to power a real time clock (RTC) and the RTC, NVRAM and battery may be integrated into a single component. The name CMOS memory comes from the technology used to make the memory, which is easier to say than NVRAM. The CMOS RAM and the real-time clock have been integrated as a part of the southbridge chipset and they may not be standalone chips on modern motherboards. In turn, the southbridge has been int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catastrophic Failure
A catastrophic failure is a sudden and total failure from which recovery is impossible. Catastrophic failures often lead to cascading systems failure. The term is most commonly used for structural failures, but has often been extended to many other disciplines in which total and irrecoverable loss occurs, such as a head crash occurrence on a hard disk drive. For example, catastrophic failure can be observed in steam turbine rotor failure, which can occur due to peak stress on the rotor; stress concentration increases up to a point at which it is excessive, leading ultimately to the failure of the disc. In firearms, catastrophic failure usually refers to a rupture or disintegration of the barrel or receiver of the gun when firing it. Some possible causes of this are an out-of-battery gun, an inadequate headspace, the use of incorrect ammunition, the use of ammunition with an incorrect propellant charge, a partially or fully obstructed barrel, or weakened metal in the barrel o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
