The Things to Know About Hard Disks

1. The hard disk’s spindle system relies on air pressure inside the drive to support the heads at their proper flying height while the disk is in motion. A hard disk drive requires a certain range of air pressures in order to operate properly. The connection to the external environment and pressure occur through a small hole in the enclosure (about 1/2 mm in diameter), usually with a carbon filter on the inside. If the air pressure is too low, there will not be enough lift for the flying head, the head will not be at the proper height, and there is a risk of head crashes and data loss. Modern drives include temperature sensors and adjust their operation to the operating environment.

2. Very high humidity for extended periods can cause accelerated wear of the drive’s heads and disks by corrosion. If the drive uses «Contact Start/Stop» (CSS) technology to park its heads on the disk when not operating, increased humidity can also lead to increased sticking (the tendency for the heads to stick to the disk surface). This can cause physical damage to the disk and spindle motor and can also lead to head crash.

3. Due to the extremely close spacing between the heads and the disk surface, any contamination of the read-write heads or disk platters can lead to a head crash – a failure of the disk in which the head scrapes across the platter surface, often grinding away the thin magnetic film. For giant magneto-resistive (GMR) heads in particular, a minor head crash from contamination (that does not remove the magnetic surface of the disk) will still result in the head temporary overheating, due to friction with the disk surface, and can render the data unreadable for a short period until the head temperature stabilizes. Head crashes can be caused by electronic failure, a sudden power failure, physical shock, wear and tear, corrosion, or poorly manufactured disks and heads. In most desktop and server drives, when powering down, the heads are moved to a landing zone, an area of the disk usually near its inner diameter, where no data is stored. This area is called the CSS (Contact Start/Stop) zone. However, especially in old models, sudden power interruptions or a power supply failure can sometimes result in the drive shutting down with the heads in the data zone, which increases the risk of data loss. In fact, it used to be procedure to «park» the hard drive before shutting down your computer. Newer drives are designed such that either a spring (at first) and then rotational inertia in the platters is used to safely park the heads in the case of unexpected power loss.

4. The hard disk’s electronics control the movement of the actuator and the rotation of the disk, and perform reads and writes on demand from the disk controller. Modern drive firmware is capable of scheduling reads and writes efficiently on the disk surfaces and remapping sectors of the disk which have failed. Also, most major hard drive and motherboard vendors now support self-monitoring, analysis, and reporting technology (SMART), by which impending failures can be predicted, allowing the user to be alerted to prevent data loss.

Notes:

enclosure	корпус
sticking	прилипание
read-write head	головка считывания-записи данных
platter	один из магнитных дисков в дисковом пакете (их может быть до 11)
firmware	встроенное ПО, записанное в ППЗУ/ПЗУ ПО
self-monitoring, analysis, and reporting technology (SMART.)	технология самоконтроля и составления диагностических отчетов, технология SMART

5. Укажите, какие из данных утверждений соответствуют содержанию текста.

1. Low pressure in the HD enclosure can increase the risk of head crashes and data loss.

2. Very high humidity can prevent the drive’s heads and disks from corrosion.

3. Increased sticking of the head to the disk surface can lead to the damage of the disk and spindle motor.

6. Выберите правильные ответы на вопросы.

1. Is the distance between the head and disk surface large or small?

(a) large;

(b) extremely small.

2. Is the head landing zone situated near its outer or inner diameter?

(a) near to its outer diameter;

(b) near to its inner diameter.

7. Прочтите предложения. Выберите правильный вариант перевода.

1. Very high humidity for extended periods can cause accelerated wear of the drive’s heads and disks by corrosion.

(a) Очень высокая влажность в течение продолжительного периода времени может привести к ускоренному износу головок и дисков по причине их коррозии.

(b) Очень высокая влажность на расширенные периоды может вызвать ускоренный износ головок и дисков коррозией.

2. Temporary overheating of the head due to friction with the disk surface can render the data unreadable for a short period until the head temperature stabilizes.

(a) Временный перегрев головки по причине трения с поверхностью диска может передавать данные, нечитаемыми в течение короткого периода времени, до тех пор, пока температура головки не стабилизируется.

(b) Временный перегрев головки по причине трения с поверхностью диска может привести к тому, что какие-то данные не будут считываться до тех пор, пока температура не стабилизируется.

3. In fact, in old models there used to be procedure to «park» the hard drive before shutting down your computer.

a) Действительно, в старых моделях существовала процедура для остановки диска до того, как выключался компьютер.

b) Действительно, в старых моделях использовали процедуру для остановки диска до отключения компьютера.