If you are going to sell your Mac or often work with files and documents of the utmost importance, you may be interested in your data to be safely hidden from other people. However, even the complete removal of the files cannot provide a high level of protection, since they remain on the hard disk as long as the space is completely filled. So, by the complicated manipulation the information can be restored.
To avoid this, after the removal of these files, you must clean the free hard disk space. Fortunately, there is “Disk Utility” in OS X which is reliable for this operation.
To start the “Disk Utility” you need to go to the “Utilities” in the software of your Mac and select the appropriate application. Then select the tab “Delete”, the button “Erase Free Space” appears in the lower left corner.
There are three erasing methods in OS X which differ not only in speed, but also the degree of data protection.
The fastest method
If you choose this option, zeros will be written automatically over the unused disk space. It takes the least time and provides an acceptable level of safety.
The golden mean
This option provides the maximum level of security during data erasure. This method is also called the method of “cleaning in seven steps.”
- Connection to the Internet. Check if it’s OK.
- Power on your Mac, choose Apple Menu-Restart. You should hold down the key combination “Command – R” while it is restarting. Release the keys when you see the logo Apple.
- When it has booted, select Utilities-Disk Utility.
- You’ll the startup disk in the list on the left, select it and click the tab Erase.
- Then, using Format Menu, select Mac OS Extended. You should type the factory name (Macintosh HD). Click Erase.
- After erasing, click Disk Utility-Quit Disk Utility. Or, as an alternative, just click the red circle at the top left window corner.
- The Mac will restart and launch the customizing wizard. Press the key combination Command-Q and select Switch Off. A new owner, being connected to the Internet, will be able to complete the reinstallation of Mac OS X setting his own data.
On the whole, this method is often used and protects your files and documents from recovery, and moreover, doesn’t take up much time.
The most secure
As you can see, this method protects your data much better than their predecessors. Clearing space occurs in 35 runs: in other words, data are written on top of the disc 35 times.
Now you know all the methods to format the Mac’s hard drive and what method to choose is up to you!