Summary: The post explains the method to delete a partition as well as merge two partitions on the Mac hard drive. It also describes the method to boot Mac from OS X Yosemite using a bootable USB drive to delete and merge the partitions.
Hard drives can be partitioned either to store system files separately from user data or to install to another Operating system such as Windows or Mac. You may have stored your data on the drive in a very organized manner, when all of sudden, you realize the need for merging two partitions. Mac OS X El Capitan offers a simple and precise way to partition Mac, delete partitions, as well as merge partitions via Disk Utility. Now the thumb rule is, if you need to merge two partitions, you may have to delete one first. For instance, to merge partition A1 and B1, you need to delete the latter one i.e. B1.
Let?s now look at how we can delete Mac partitions. Since manual methods are prone to data loss, it is recommended to backup partitions before following any of the steps below:
Delete Partition with Disk Utility
Step 1: Launch Disk Utility and select the partition that needs to be deleted under logical menu
Step 2: Click on the Partition tab
Step 3: Now, highlight the partition that has to be deleted
Step 4: Next, click on the minus (-) sign and then select Remove
When the procedure completes, exit the Disk Utility. With this, the selected Partition B1 is deleted from the Mac hard drive.
Merge Mac Partition with Disk Utility
Let?s access the two partitions that have to be deleted in the partition pie chart and then delete and merge them right from the utility window.
Step 1: From the Disk Utility window, select the drive where the two partitions (that are to be merged) exists
Step 2: Click on Partitions tab, a pie chart will appear with partitions details
Step 3: You can click on Partition pie chart to view the details of both the partitions.
Step 4: Select the partition that needs to be deleted. Taking the earlier example ? Partition B1
Note: Remember to back up the partition else you will lose the data existing in that partition.
Step 5: Click on the minus (-) sign and your partition will be deleted
Step 6: Select Partition A1 and click and hold its corner to drag it for covering the area previously covered by Partition B1.
Now you will notice that entire volume which is previously allocated to Partition A1 and partition B1 is now taken over by Partition A1.
If you are unable to access Disk Utility via Applications folder, you can select to access it from the boot menu. For this, you need to go through the next section.
Open Disk Utility from Boot Menu
1. Restart Mac
2. While its starting up, press and hold Command + R keys altogether
Boot Mac from OS X Yosemite
Disk Utility in El Capitan is the renewed version of what it used to be in the earlier editions of Mac OS X. Although it comes with several new features, it incorporates several functionality issues as well.
The procedure to merge and delete Mac partition must work as expected; if no, then you may create a bootable external drive with OS X Yosemite. Next, boot your Mac using this USB drive as it will allow you to access and work with the older version of Disk Utility.
To get started with the previous version, follow the steps below:
Step 1: Copy all the contents of Partition B1. This recommended only if enough space is available, else take the backup of the respective partition
Step 2: Boot from the external drive. From the given options, select Disk Utility
Step 3: Next, select the particular drive where the partitions need to be merged
Step 4: From the partition pie chart, select and delete Partition B1 by clicking on the given minus (-) sign
Step 5: Next, click on the corner of Partition A1 and then select and drag it over the area previously acquired by Partition B1
Even though deleting and merging Mac partitions using Disk Utility is the easiest method for organizing partitions as desired, you can also execute these tasks through Command line interface. But the procedure can be quite complicated. This is because if any of the commands are entered incorrectly in the terminal window, it may affect the entire partition as well as the incorporated data contents.