Securely Erasing a Bad / Dead Hard Drive

Here’s the situation, your hard drive died and you’re about to take it to the Apple Store for repairs. You have a backup handy because you’re a good computer user and Time Machine is so easy to use. You don’t need any Data Recovery.

The Apple Technician is going to do two things. First, they are going to replace your drive – if it’s covered under warranty / AppleCare. Then, they are going to keep your old one and send it back either to Apple or the manufacturer – Seagate, Fuji, Hitachi, etc. Since your drive has sensitive information on it, like bank records, tax returns and pictures of you in a swimsuit, what do you do?

Erasing a Drive that Doesn’t Work:

You already know how to securely erase a hard drive but that’s if the drive can still spin and the heads function. In the case of bad sectors, a secure erase will still work but be prepared for it to take forever.

A dead drive will just power on and click – if it powers on at all.

What do you do? Smash it with a hammer? Thermite? Throw it off a cliff into the ocean? Environmental and safety concerns aside, if someone wanted to recover your data, they still can. Well, maybe not with the thermite.. Most important though, Apple’s definitely not going to warranty a smashed, pile of ashes that went for a swim.

You’ll need to Degauss the drive.

What is Degaussing:

Degaussing is subjecting your drive to such a strong magnetic field that all the sectors on your drive lose their data. It’s quick, painless and works. It’s also relatively inexpensive. However you’ll have to take the drive to either a TV / Electronics or a Computer repair shop to get it done. Corporate data destroying companies also do this, but usually for large amounts of drives or backup tapes. I don’t recommend buying one unless you plan on entering the degaussing business – they’re pretty expensive.

How to avoid ever needing this?

What you can do to avoid a headache like this is to use encryption. By turning on FileVault, your entire home folder will be encrypted. You can enable this for all accounts on your Mac.

Note: If you use FileVault, just remember Time Machine won’t back up the encrypted folder until you log out.

Now in the case of a completely dead hard drive, any type of data recovery is next to impossible with encryption. Why? Because in addition to dealing with the pain of standard data recovery, whatever is recovered is encrypted.

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