By properly, we mean deleting the unwanted partition and returning that disk space back to your primary partition, without any data loss.
For whatever reason, you’ve created a second partition on your Mac, you now want to delete it and have the space it took up returned to your primary partition. No problem – just follow these steps:
- Run a Time Machine backup. Yes it’s a pain, but you cannot be too safe when it comes to altering partitions. This is critically important.
- Close any open Apps and save your work. Restart your Mac, but as it starts up, hold down the Apple key (⌘) and the r key at the same time (⌘+r). This will start your Mac in “Recovery Mode”.
You’ll be presented with a screen asking you to select your language. Do so, and then click the “arrow button” to continue.
- From the OS X Utilities menu, select Disk Utility and then click the Continue button.
- Select the disk that has the partition you want to delete (not the partition itself).
- Now click the Partition menu, and in the Partition Layout section, select the partition you want to delete by clicking on it once.
- As illustrated in the screenshot below, the partition I want to delete is called Other Partition (yes rather aptly named). You’ll know it has been properly selected because a ‘blue bar’ will surround it. Now click the small “minus button” ( – ) to delete this unwanted partition.
- Make sure that the notification window has the correct information. That the This partition will be erased: line contains the correct partition, and the This partition won’t be erased: partition is the one you do not want deleted. Now, click the Remove button.
- Once the partition has been deleted, you’ll notice that even though your “primary” (and now only) partition is selected, it’s still not displaying the correct size. Let’s fix that.
- In the Partition Information section, enter in a number that’s larger that your drive is. As you can see in the screenshot below, I entered 133 – even though my hard drive is only 128 GB. Now, hit the enter (return) key on your keyboard.
- The number will change to the correct size – all of the space that the old partition took up has now been returned to your primary one. Click the Apply button in the bottom right corner of the Disk Utility screen.
- Make sure that the correct partition is listed on the This partition will be resized: line. Make absolute certain that the ‘warning’ window says noting about erasing or losing data. Now click the Partition button.
- You’re done! Close the Disk Utility and restart your Mac by selecting the Apple Button and then Restart
- Let your Mac boot normally, and once it’s up and running – check Finder and/or Disk Utility to confirm that both the old/unwanted partition is gone, and it’s space has been returned to your drive. That’s it!