Add, delete or erase APFS volumes in Disk Utility on Mac
Apple File System (APFS) allocates disk space on demand. When a single APFS container (partition) has multiple volumes, the container’s free space is shared and can be allocated to any of the individual volumes as needed. Each volume uses only part of the overall container, so the available space is the total size of the container, minus the size of all volumes in the container.
On your computer, macOS is installed on a set of volumes known as a volume group. The volume group consists of one volume used for the system files (named Macintosh HD) and another volume used for data (named Macintosh HD - Data).
Add an APFS volume
Each volume you add to an APFS container can have a different APFS format, if needed.
Go to the Disk Utility app
on your Mac.If Disk Utility isn’t open, click
in the Dock, type Disk Utility in the Search field, then click .Select an existing APFS volume in the sidebar, then click
in the toolbar.Enter a name for the new APFS volume.
Click the Format pop-up menu, then choose an APFS format.
If you want to manually manage APFS volume allocation, click Size Options, enter values in the fields, then click OK.
Reserve Size: The optional reserve size ensures that the amount of storage remains available for this volume.
Quota Size: The optional quota size limits how much storage the volume can allocate.
Click Add.
When the operation is finished, click Done.
Delete an APFS volume
When you delete a volume, all the data on the volume is permanently erased and the volume is removed from the container.
Go to the Disk Utility app
on your Mac.If Disk Utility isn’t open, click
in the Dock, type Disk Utility in the Search field, then click .Select the APFS volume you want to delete in the sidebar.
Click
in the toolbar.If the button is dimmed, the selected volume can’t be deleted because it’s in use. To delete the volume, you need to open Disk Utility in macOS Recovery. See the Apple Support article If you can’t start up from macOS Recovery.
Do one of the following:
If you selected a volume group: Click Delete to delete the volume group.
If you selected a volume that’s a member of a volume group: Click Delete Volume Group to delete the volume group, or click Delete to delete only the selected volume.
If you selected a volume that isn’t a member of a group: Click Delete to delete the volume.
When the operation is finished, click Done.
Erase an APFS volume
When you erase a volume, all the data on the volume is permanently erased and the empty volume remains in the container.
Go to the Disk Utility app
on your Mac.If Disk Utility isn’t open, click
in the Dock, type Disk Utility in the Search field, then click .Select the APFS volume you want to erase in the sidebar.
Click
in the toolbar.If the button is dimmed, the selected volume can’t be erased because it’s in use. To erase the volume, you need to run Disk Utility in macOS Recovery. See the Apple Support article If you can’t start up from macOS Recovery.
Enter a new name for the volume, if desired.
If you want to change the format, click the Format pop-up menu, then choose an APFS format.
Do one of the following:
If you selected a volume that’s a member of a volume group: Click Erase Volume Group to erase all volumes in the group, or click Erase to erase only the selected volume.
If you selected a volume that isn’t a member of a group: Click Erase to erase the selected volume.
When the operation is finished, click Done.
You can’t delete or erase your startup volume. See Erase and reformat a storage device.