Securely Erase Your Mac’s Solid State Hard Drive

Do you want to either sell or retire a Mac that has a solid state hard drive (aka Flash Storage)? If so, it is prudent to securely erase the hard drive beforehand. Here are instructions on how to do this. This procedure will make all of your personal data inaccessible. During this process we will be enabling FileVault, which encrypts everything on your Mac’s hard drive. Then we will reformat the hard drive which prevents anybody from accessing anything that was stored on the hard drive.

These instructions assume your Mac is using OS X Lion (aka OS X 10.7) or newer.

Note: This process can take many hours so you may want to start the encryption at the end of one day and let your Mac’s hard drive get encrypted overnight.

  1. Click on the Apple menu and select System Preferences
  2. Click on Security & Privacy
  3. Click on the FileVault tab
  4. Click the padlock icon in the lower left corner to unlock this window so you can make changes. You’ll be prompted to enter your Mac user account’s password.
  5. Click the button to Turn On FileVault encryption
  6. Follow the prompts to enable FileVault. [You’ll see prompts about creating a Recovery Key and storing it with Apple. You don’t need to do this since you’re going to be erasing everything when you reformat the hard drive, in a few steps.]
  7. Restart your Mac when prompted to let the encryption process begin.
  8. Sit back and wait while everything on the Mac’s hard drive is encrypted. This can take many hours. You can open up the Security & Privacy system preference pane to monitor progress and view a time estimate.
  9. After FileVault has finished encrypting the hard drive then click on the Apple menu, select Restart
  10. Immediately press and the Command and R keyboard keys. This’ll trigger the Mac to startup from its Recovery Partition.
  11. When it has started up you should see a window similar to this one:Recovery Partition Options
  12. Click on Disk Utility from the list of options.
  13. Select your Mac’s hard drive and click the Erase tab
  14. Set the Format to Mac OS Extended (Journaled) and then click Erase
  15. Wait about 20-30 seconds for the hard drive to be erased
  16. Quit Disk Utility
  17. Optionally, click on Reinstall Mac OS X from the list of options. Follow the prompts to re-install the Mac operating system. This process typically takes about an hour.