Tuesday, October 14, 2008

It's a hard drive gonna fail

Ever wonder what makes a hard drive suddenly give up the ghost? In almost every situation that the "heart" of a computer goes south, I am amazed. It is not unlike people who have atherosclerotic heart disease. One minute they appear healthy and robust and the next minute they have keeled over suffering from a myocardial infarction. As any schoolchild can tell you (and you can never find one when you need one), a hard disk drive (or HDD) is a collection of spinning disks that revolve at very fast speeds, typically from 5400 to 7200 rpm (revolutions per minute), for most consumer models to extremely fast enterprise models that cruise at 10,000 rpm or more. Because of the stability of hard drives and for processors to be able to read and transfer data to them, the most modern computers demand larger hard drives and faster speeds to be able to access the data more readily. The faster the disk drives spin, the more heat is generated and the greater the demand for cooling inside. Except for a small hole designed to vent the pressure that rises inside, hard drives are sealed. Most people have never seen the insides of these marvelous devices, but they are exquisite in the simplicity of their design. But therein lies the rub. The simplicity of their design belies the complexity of technology that make hard drive disks perform so well. There is a motor that physically spins the disks and a very light head that reads them as they spin. Oftentimes the motor will fail due to an electrical short or the arm that holds the head may fail to find its "landing spot" and may score the platters, which are very similar in appearance to CD ROMs or DVDs. Hard disk drives have evolved through the years from SCSI (small computer serial interface) types to PATA types (IDE and EIDE drives) to the more recent ATA and SATA (Serial ATA) types. Yet, they are all remarkably similar. When they fail, they fail abruptly, many times with no advance warning. It boggles the mind what it is. If RAM (memory) is too low for an operating system, it may result in excessive paging to the hard drive. This extra overhead and the physical constraints of having to keep paging files on the drive have often contributed to hard drive failures that I have seen. One unfortunate fellow replaced his hard drive three times before I insisted he upgrade the memory in his Windows 2000 computer to 1GB RAM. He hasn't had any problem with his hard drive since. An occasional defragmentation of a hard drive is a good practice, but with the larger drives that abound today, less defragmentation seems to be the rule. Windows XP and Vista operating systems analyze drives prior to defragmentation and more times than not don't recommend drives to undergo defragmentation. Deleting unnecessary and temporary files is also a good rule to follow to get hard drives to work at optimum speed. One of the best things to do to maintain a hard drive, though, is to get a good surge protector. More times than not a small surge through an AC line will jump the power supply and the motherboard and kill the hard drive. Don't ask me why. Suffice it for me to say it just happens. The main rule to remember, though, is backup the data regularly. Like the humans that invented them, hard disk drives are all destined to die one day. It's not if it will fail, it's when. Remembering to upgrade RAM, using a good surge protector or UPS (uninterruptible power supply), and performing occasional deletion of files and defragmentations are all good starts. Keeping your fingers crossed is also highly recommended.

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