I recently bought an external hard drive, a Seagate Backup Plus. Is it
vulnerable to magnets? I know that internal hard drives are vulnerable, but I’m
not sure about the external ones. Also, if they are vulnerable, do all external
hard drives become vulnerable as well or just certain models?
In this excerpt from
Answercast #76, I look at how paranoid we (as normal computer users) need to
be about magnets and hard drives.
Magnets damaging hard drives
You know, to be honest, magnetics is something that I have never, ever worried about. There’s… I don’t know if I want to call it an “urban myth” or just a misconception that a magnet will do hard drive damage.
The best way to describe this idea is to trace it back to its roots. Back in the day, we didn’t use hard drives; we used floppy disks. Floppy disks were media that were enclosed in a kind-of plastic wrapper. You could get a magnet very, very close to the magnetic media so that even so a small magnet could scramble the data on the media… if you were intent on it, if you really ran it around a little bit.
It certainly wasn’t the case that data, even then, was easily erased. But it definitely was possible to erase it, even with a small magnet.
In fact, there were bulk erasers, big magnets that you could get that would allow you to demagnetize or scramble the data on a stack of floppies all at once. It was using, like I said, a big external magnet, a big heavy thing.
Once we moved to hard drives, while technically, hard drives are magnetic media, the magnets that you and I typically have aren’t nearly powerful enough to have any noticeable impact on what goes on inside the hard drive itself. I don’t care whether the hard drive is internal to your PC or in an external enclosure; the magnets that you and I have simply don’t have the power to do any serious damage.
Now, there’s still a lot of debate on whether or not that big, heavy bulk-erasing magnet actually does anything to external hard drives. So, the fact that there’s a debate should right away tell you that it’s not the most effective way to erase hard drives.
And in fact, what it should also tell you is that, gosh, hard drives, if there’s even a question, aren’t really that sensitive to magnetism as perhaps we thought. External magnetism, that is. So, I certainly don’t recommend bulk erasers as a way to erase the data on your hard drive. I don’t believe it’s effective.
I don’t believe it’s a guaranteed erase by any stretch.
How big is your magnet?
And day to day, I mean, you’re not putting bulk erasers next to you external hard drive or next to your PC. You’re not putting magnets anywhere near that kind of power, near the devices you’re concerned about.
So practically, it’s just not something you and I need to worry about on a day-to-day basis.
So, the short answer is no. Don’t worry about it. Keep the big magnet that you might be using (like at the back of your super, large speakers, or the bulk eraser that you had from 30 years ago), keep that somewhere else – but for day-to-day stuff, for the average person, for practical use, no. It’s not even something to be worried about.
(Transcript lightly edited for readability.)
Next from Answercast 76 – Are hibernate and standby easier on a computer than rebooting it from scratch?