Factors that can hurt a drive
- Let's talk about factors that can harm hard drives. Probably the biggest one is heat. And a lot of that depends on the actual enclosure the drive is in. If it's in a computer the engineers that have built the computer have already pretty much figured out air flow and cooling. So that's very rarely an issue. If you have an external hard drive like this one, this one happens to be enclosed in plastic, and the problem with the plastic hard drive is that plastic is an insulator. A good choice of material for enclosing a hard drive is aluminum, which is a very good conductor of heat and it will tend to wick the heat away from the drive itself.
This kind of a drive, (knocking) is plastic as I said, and since plastic is an insulator it's going to contain the heat more. The physical position of a hard drive is also very important. Where you locate an external drive is a big factor when it comes to heat, particularly if it's sitting on a desk in sunlight. Sunlight can heat up a drive so fast that you would not believe how quickly you can bake the insides of it.
And a hot drive is a failing drive. The next factor involved is movement. Remember the platters that we talked about that are spinning at about 67 miles an hour on the edge? They act just like a toy gyroscope like this one. I'm going to spin it up to give you an example. As it spins, it's going to fight the tendency to tip over. If I try to move it it's going to fight me. That's fine for a toy, but in a hard drive if I do this, the problem I'm going to have is that I'm affecting those platters and they could cause the heads to crash, destroying data.
So fast movements of a hard drive is also a really bad idea. The best way to keep a hard drive from failing by twisting it is to keep it parallel to the surface you picked it up from. Another factor that affects hard drives is its location. Altitude is a factor. If you go above a certain height, and it depends on the drives, if you go above a certain height they're going to fail because most hard drives breathe and the vacuum can be a problem.
Some of the newer drives like the Heliums, actually have that gas inside which protects them from altitude. But those are not in the mainstream yet. Another factor is humidity. If the drive is maintained in a very humid climate it's going to tend to corrode, particularly if you let it sit around. Sudden temperature changes are another thing, because inside the drive the moisture will condense on the platter and cause drive failures with the heads.
And finally, of course, vibration. If you shoot a lot of photographs or travel a lot in helicopters, it's not a really good idea to have the hard drive sitting on a vibrating surface, because again, it can cause the head to crash. Another set of factors that affect hard drives are simply old age. They have a lifespan. Hard drives are set up with something called an MTBF, mean time between failures. Mean is a term, a mathematical term, that means average.
So the average time between failures is measured in hours. So the mean time between failure can be one that fails right out of the box or runs continuously for a million hours. Another factor is spinning the drive up and spinning it down. That means turning it on and turning it off. The more times you do that the shorter the drive's lifespan. And finally long-term storage. If you take the drive, put it on a shelf, and let it sit no one really knows how long that drive is going to last or if it will even spin up at all.
In the next section of this course we will look into some of the factors and what happens when hard drives sit for a really long time. I actually have a whole bunch to show you.
