Ah computers, we have invested our dollars in them for gaming and or for work, and storing our information, those nifty pictures of your trip out of the country, the beautifull visages, mountain ranges and the memories with your loved ones, and all this can dissapear in a second!
You see, we often overlook the fragility of a hard drive, the magic that happens every time we boot up our system, how the drive heads float and glide across the disks surfaces on a small bead of air, how the magnetic fields are read, interpreted, in a well orchestrated fashion. time after time, without failure, a work of art, but things can always fail, and hard drives are not meant to work perfectly forever!.
Since the dawn of computing, computers where used to calculate data and get results, but there was also the need to store information in a way that could be readable at a later time, the binary system has always been the way to go, in the form of circuity inside the computer processors, switches that have 2 states (binary), on and off, data is broken down in binary code, zeros and ones, and soon it was possible to store data, in the form of "punch" cards, thick paper cards with holes in them to store a 1 (a hole) and a 0 (no hole), and soon in the form of magnetic media, a positive magnetic field for a 1 and negative field for a 0, magnetic tapes, magnetic disks, all you needed was head that reads and writes the magnetic field accordingly, and this method became the mainstream even to our days (flash memory media came to aid us, but more on that later)
Just as a magnetic head would send pulses of positive or negative energy along a magnetic tape, the same method was applied, take the strip , lay it down and bend it to form a flat circle, you got yourself a track!, now bunch up a lot of tracks together, and you have yourself the basic principle of magnetic disk media, From the old 8" 1/2 , 5" 1/4 or 3" 1/2 floppy drives, up to metal hard disks, a round plate surface full of tracks, in which you can store data with magnetic pulses.
WHERE IT FAILS
in order to access information, the write/read head needs to move along the "tracks" reading the magnetic fields, a succession of ones and zeros , its easier to spin the disk, and have the head, move up and down along the tracks reading your data, and the head needs to move back and forth FAST!, also, in order to store more 1's and 0's on the plate surface, you need to get the head closer, but if you get too close you scratch the disk and loose your data!, as the platter spins, it crates a small air bed, a microscopic "pillow" of air in which the head floats, a space thinner than a humans hair!, and while HArd drive manufacturers do a great job at this, i think you can already see where i am going with this:
1-The platter spins due to a Magnetic Motor, and as calibrated and reliable as it is, it could one day start slowing down, or fail to function, this means you can access your data anymore
2-The heads are controlled by a magnetic motor as well, and move the head with great precision, up and down across the platter, but it can too fail and become unable to travel the tracks and read your data
3-The heads float on the platter, given its spinning fast enough, there are systems to protect it in the case of power failure so the heads do not "crash" into the drive, but nothing last forever and this happens.. a lot!, scratched platter = loss of data
Hard drives are sold with a MTBF, a Mean Time Between Failures, basically the company estimates how many hours the drive will hold up until it becomes unstable and fails, commercial drives are sold with a MTBF of around 30,000 hours, that means the drive is expected to work correctly for about 3 years turned on before it can start failing, pricier Enterprise class hard drives are sold with a MTBF of around million hours, estimating a life of 100 years!
But.. these are just estimates, you can go and buy a new hard drive and have it fail the next day, and you can also have a 10 year old computer, with its hard drive functioning well over its MTBF and have no problems!
GET TO THE POINT ALREADY
What do you do, with the impending notion that a hard drive could die at any time? SIMPLE, make COPIES of whatever is valuable to you! :D
Those 4 Gigabytes of pictures and videos of your last vacation sitting on your Desktop? Burn them to a DVD, store it in a safe place (a SAFE too, get it?) Its always wise to have a copy because you never know when your hard drive might die, or in the case of laptops your computer could get stolen, or lost ( but hopefully this never happens to you!)
Just as you have a copy of your birth certificates, school papers, car or house documents, a copy of your valuable data is your best bet against hard drive failures!
because remember, only humans make mistakes... and humans also make computers... what..?
See you soon :D