by Martin Haschka

Created on: September 22, 2009

Imagine a plane flying 5 yards above the ground on autopilot at 600 miles per hour .... A scary thought, isn't it? You would neither want to be a passenger in that plane, nor would you care to be anywhere near its path.

What is going on inside your hard drive is pretty much the same. Thankfully nobody lives inside that hazardous environment who might come to harm during such a stunt. But a crash of the plane that cruises above the precious data stored on your hard disk still comes at a high price.

A hard drive typically consists of a stack of magnetic disks inside a sealed box. Each disk has a diameter of 3.5 inches and contains your data as well as your installed software. Above each disk, attached to a sideways moving arm, is a read/write head, which reads the data on the disk or writes new data onto it while the disk below it rotates.

Most modern hard drives operate at a speed of 7200 rpm or above, which simply means the magnetic disks inside your hard drive rotate around their centre 7200 times per minute. With the diameter of the disk given you can quickly work out that the outer rims of those disks move at a speed exceeding 75 miles per hour when in full motion.

The read/write head hovers only one thousandth of a millimetre above the disk. A human hair has a diameter of one tenth of a millimetre, and even a dust particle or a fingerprint are larger than the distance between the hard disk and the read/write head. Therefore it's not a good idea to open up a hard drive to look what inside it. Also the bold initiative to repair your hard drive yourself is bound to cause more harm than good, as inevitably dust or other foreign particles will get into the formerly sealed unit. If they do, it's a perfect recipe for disaster, for sooner or later those foreign particles will get caught between the disk and the read/write head, causing damage to both, in some cases even forcing the head to touch the disk itself. In the aftermath of this unwanted contact your hard drive is about to meet up with destiny.

Once the read/write head crashes on to the disk a self increasing process is triggered: tiny splinters break lose, hit the rotating disk, get sped up, crash back onto the disk again causing more tiny splinters to break lose. Every single one of those splinters used to contain a little of your data, now it's turning against the rest of your files, destroying them in the process.

Assuming you don't plan to open up your hard drive to verify the above information, what

• 1
• 2
• 3
• Next Page >>