Thursday, 27 November 2014

What Erase free spaces on Mac HD indicates?

The Macintosh hard drive incorporates huge amount of spaces for the files or folders to be stored on. The entire hard drive space is commonly segregated into Used and Free spaces. The OS X assigns data in the form of files and folders to spaces, which becomes occupied or used. The unoccupied spaces on the OS X hard drive is now to be know as free spaces. But, this is not the terminology always. When an application is uninstalled or a file is removed from it’s location then that location becomes a free space. This free space will be free till OS X writes another set of data onto it. And when it does, new files overwrite the free space.

What overwriting does to free spaces?

Whenever, a file is deleted from the hard drive, it remains on its location, though invisible to the user. The user believes the file is gone since OS X has removed it but it remains in dormant form on its drive location. Such deleted files can be restored later with the help of powerful Mac deleted files recovery software. But if the OS X manages to overwrite deleted file information with the help of overwriting new files, then chances of file recovery are null.

Since hard drive has millions of sectors, user on its own term cannot ask OS X to overwrite a specific location that is holding deleted file information. On the other hand OS X too randomly assigns drive location to a new file. So, it may or may not overwrite a file which user doesn’t want to be recovered.

How to erase free spaces on OS X Mac?

Finder << Application << Utilities << Disk Utility

Follow the above path to launch Disk Utility. When windows show up, switch to ‘ERASE’ tab.

Select Macintosh HD. You may also select a partition if the hard drive is segregated. In below case, I selected one of my partitions to erase all free spaces from it.

  • Once Macintosh HD or a partition is chosen, the buttons in the tab will activate. Among them, can be seen ‘ERASE FREE SPACE…’. This is the one button to do today’s job of erasing free spaces.

  • Do carefully read the text, which is displayed on the minor window that pops-up. It says, OS X will erase all unused spaces on the selected disk to halt recovery of deleted files.  Once sure, click the button to start the process.

Disk utility will take some time to complete the task of erasing free spaces. In between you can terminate the process abruptly by clicking on ‘SKIP’ button.