Deleting Data Know How – Tech Tuesday
Recently, the hard drive in my iMac was showing the early signs of it failing. It was taking longer to start up, and shut down, as well as it taking forever for programs and files to open. The many things I tried to correct the problem didn't work, so I decided to replace it. But what about the data on the old drive? How would I get rid of the drive without worrying about the data falling into someone hands?
If you're a little security conciseness like me, you've thought about how to protect your personal data. Digital tax returns and and other files of a sensitive nature you just don't want everybody to be able to see. But just dragging the file to the trash is not enough sometimes. Those files could be recovered even after your delete them. For example, I was given an old computer by someone, with the original hard drives, that had been reformatted, still in them. Being the curious type I wanted to see if I could recover data from the drives, just to see if I could do. Using a free utility I downloaded, I was able to retrieve documents, pictures and even a few porn pictures that were once saved on the drive.
At that point I figured knowing how to delete data was a good idea. So I did some research and found that when you delete a file on your computer, it doesn't erase it. It just makes a note in the file keeping part of the hard drive that the area where the file was is open for use, and just overwrites the data if it needs the space to save a file to. So you could delete something 6 months ago and the files are still there because the hard drive hasn't written anything to that area. This was by design to save system resources. But you can download programs to overwrite that area multiple times to make sure it's gone.
But a quick tip with new solid state drives: These methods don't work as they write and read data differently. On these types of drives, doing the basic erase actually makes the file unrecoverable. Solid state drives have a limited read and write lifetime, so you would be shortening the life of your solid state drive if you constantly did "secure deletion".
Over writing the area two times is enough to make the data virtually unrecoverable, or too much of an investment for someone to want to retrieve the data. Some programs offer a "secure" wipe that over writes the area thirty times or more! This is kind of overdoing it and takes up time and resources the computer could use for other things. But if that is your thing, go for it. But a simple program that over writes the data two or 3 times is enough. Unless you're a complete security nut or the United States military in which case, secure data erasure is simply destroying the hard drive physically with an industrial grade shredder. But if you don't have that kind of money, a sledge hammer or drilling a hole or two in the drive will do nicely. And makes you feel better, Office Space style.