Wednesday, June 24, 2009

Don't dump old drives!

kw: observations, recycling, computer security

A local PBS station, WHYY in Philadelphia, had a segment on Frontline/World last evening about e-waste and electronics recycling. When old electronics go to a "recycler", they are likely to wind up in a place such as Ghana or southern China, where two main industries flourish on our waste.

Firstly, the metals are reclaimed. This is done by burning the plastics off the metals and reclaiming iron and copper. Magnets from old speakers are used to sift through debris for iron bits that would otherwise be missed. Circuit boards usually get special treatment: they are cooked to remove the chips, which often contain gold in their traces (internal wiring) or contacts.

Secondly, the disk drives are put up for sale. Some are used to upgrade local computers, but many are plundered for their remaining data. Even if the files have been "erased", their content is still sitting on the disk, and "file recovery" or "unerase" programs can reconnect the data with the file's header in the folder. There was a disturbing sequence showing how easy it was for a technician to read personal information from a discarded hard drive.

People, if you are going to discard an old computer, first go to fileshredder.org and download FileShredder. Run it against everything it will let you shred. Then it might be safe to discard the hardware. If you want to be really sure, remove the hard drive and either keep it or remove its top and pour in a spoonful of Comet® cleanser (abrasive)…or just smash the platters with a hammer.

These are some of the old disk drives I've kept. Their sizes are 40Mby, 511Mby, and 2.5Gby, from left to right. I took the top off the 511Mby one to show the platters and reading head. In the closeup below you ought to be able to see that this one has two platters. There are four heads to cover the four surfaces on which data goes.

Back when 40Mby was a lot of disk, I managed to fill the first one pretty full. I haven't opened it to see how many platters there are, but I suspect it is either three or two. I find it amazing that my son just bought, for less than $100, a disk drive that holds a Terabyte; that's 25,000 times the capacity. One drive I don't show is a disk pack from a CDC 6400, a removable pack that holds 50Mby; it is more than a foot in diameter and seven inches tall. I'm pretty safe with it; the drive needed to read it doesn't exist any more.

Before I stopped using each computer, I copied all the data to its replacement machine. We have one more old machine that we will discard, maybe soon. I've already copied the data to a newer machine's secondary drive. I've gotten smarter over the years, and now keep most data on an external drive. Whenever I move a block of files to it, I back them up to a DVD. That way I have all our documents since we began using home computers in the early 1980s. But I don't let copies of old data get out of doors! And neither should you!!

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