Instructions apply to Mac OS X Leopard (10.5.8) and later.
Do not attempt to use earlier versions of Disk Utility for the process provided here.
Open Disk Utility, which is located in/Applications/Utilities/.
Internal drives and volumes appear in the Disk Utility sidebar.
Physical drives are listed with a generic disk icon.
Volumes are listed below their associated physical drive.
In the sidebar, opt for volume you want to resize, then selectPartition.
If you’re using Apple File System (APFS), Apple recommends not partitioning your disk.
Instead, you should create however many APFS volumes you need within the single disk partition.
To add a new partition to an existing disk, complete the following steps:
OpenDisk Utilityat/Applications/Utilities/.
Current drives and volumes appear in the Disk Utility sidebar underInternalorExternal, as appropriate.
In the sidebar, select a volume, then selectPartition.
SelectPartitionfrom the pop-up window.
SelectAdd(the plus sign).
Then, in theNamefield, punch in a name for the new partition.
From theFormatlist, pick the file system format you want to use.
InSize, key in a size in gigabytes for the new partition.
Or, you might drag the line control between the two resulting partitions to change their sizes.
To reject the changes you’ve made, selectRevert.
To accept the changes and repartition the drive, selectApply.
Disk Utility will display a confirmation sheet that lists how the partitions will be changed.
SelectPartition, then selectContinue.
When the new partitions appear, selectDone.
Icons for each partition appear in sidebars of both Disk Utility and Finder.
For example, say that you’ve partitioned a drive into two volumes namedvol1andvol2.
it’s possible for you to deletevol2and resizevol1to take over the available space without losing the data onvol1.
The opposite, however, is not true.
Deletingvol1doesn’t allowvol2to expand to fill the space thatvol1use to occupy.
When you delete a partition, you lose all the data on it.
So, be sure to back up everything on it first.
To delete an existing partition, complete the following steps:
Open Disk Utility, which is located in/Applications/Utilities/.
Current drives and volumes will appear in the Disk Utility sidebar.
Drives have a generic disk icon.
Partitions appear beneath their associated drive.
In the sidebar, pick the partition you want to delete, then selectPartition.
In the pie chart, go for the existing partition you want to delete, then selectDelete.
Disk Utility will display a confirmation sheet listing how the partitions will be changed.
SelectApply, then selectPartition.
When the partition disappears, selectDone.
